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Posted to dev@sling.apache.org by GitBox <gi...@apache.org> on 2020/07/15 16:48:41 UTC
[GitHub] [sling-org-apache-sling-discovery-support] stefan-egli opened a new pull request #1: SLING-9589 : expose discovery metrics
stefan-egli opened a new pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1
Metrics are exposed via dropwizard, and only using a TopologyEventListener without any further changes needed. Hence the change is actually in the support bundle, not in the main implementation bundle.
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[GitHub] [sling-org-apache-sling-discovery-support] stefan-egli commented on a change in pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
stefan-egli commented on a change in pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#discussion_r468711823
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
+ propertyChangedEvents.incrementAndGet();
+
+ updateProperties(newView);
+ }
+
+ private void updateLocalClusterInstances(TopologyView oldViewOrNull, TopologyView newView) {
+ final ClusterView newLocalClusterView = newView.getLocalInstance().getClusterView();
+ localClusterInstances.set(newLocalClusterView.getInstances().size());
+
+ if (oldViewOrNull == null) {
+ localClusterJoins.addAndGet(newLocalClusterView.getInstances().size());
+ } else {
+ final ClusterView oldLocalClusterView = oldViewOrNull.getLocalInstance().getClusterView();
+ final InstancesDiff diff = new InstancesDiff(oldLocalClusterView, newLocalClusterView);
+ final Collection<InstanceDescription> added = diff.added().get();
+ final Collection<InstanceDescription> removed = diff.removed().get();
+
+ if (added != null && added.size() > 0) {
Review comment:
+1, removed
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
+ propertyChangedEvents.incrementAndGet();
+
+ updateProperties(newView);
+ }
+
+ private void updateLocalClusterInstances(TopologyView oldViewOrNull, TopologyView newView) {
+ final ClusterView newLocalClusterView = newView.getLocalInstance().getClusterView();
+ localClusterInstances.set(newLocalClusterView.getInstances().size());
+
+ if (oldViewOrNull == null) {
+ localClusterJoins.addAndGet(newLocalClusterView.getInstances().size());
+ } else {
+ final ClusterView oldLocalClusterView = oldViewOrNull.getLocalInstance().getClusterView();
+ final InstancesDiff diff = new InstancesDiff(oldLocalClusterView, newLocalClusterView);
+ final Collection<InstanceDescription> added = diff.added().get();
+ final Collection<InstanceDescription> removed = diff.removed().get();
+
+ if (added != null && added.size() > 0) {
+ localClusterJoins.addAndGet(added.size());
+ }
+ if (removed != null && removed.size() > 0) {
Review comment:
+1, removed
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[GitHub] [sling-org-apache-sling-discovery-support] stefan-egli merged pull request #1: SLING-9589 : expose discovery metrics
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URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1
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[GitHub] [sling-org-apache-sling-discovery-support] mreutegg commented on a change in pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
mreutegg commented on a change in pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#discussion_r468523625
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
+ propertyChangedEvents.incrementAndGet();
+
+ updateProperties(newView);
+ }
+
+ private void updateLocalClusterInstances(TopologyView oldViewOrNull, TopologyView newView) {
+ final ClusterView newLocalClusterView = newView.getLocalInstance().getClusterView();
+ localClusterInstances.set(newLocalClusterView.getInstances().size());
+
+ if (oldViewOrNull == null) {
+ localClusterJoins.addAndGet(newLocalClusterView.getInstances().size());
+ } else {
+ final ClusterView oldLocalClusterView = oldViewOrNull.getLocalInstance().getClusterView();
+ final InstancesDiff diff = new InstancesDiff(oldLocalClusterView, newLocalClusterView);
+ final Collection<InstanceDescription> added = diff.added().get();
+ final Collection<InstanceDescription> removed = diff.removed().get();
+
+ if (added != null && added.size() > 0) {
+ localClusterJoins.addAndGet(added.size());
+ }
+ if (removed != null && removed.size() > 0) {
Review comment:
Same as above.
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
Review comment:
```suggestion
* There shouldn't be an awful lot of properties, so int sounds more than enough
```
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
Review comment:
Remove `oldView` because it is unused?
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
+ propertyChangedEvents.incrementAndGet();
+
+ updateProperties(newView);
+ }
+
+ private void updateLocalClusterInstances(TopologyView oldViewOrNull, TopologyView newView) {
+ final ClusterView newLocalClusterView = newView.getLocalInstance().getClusterView();
+ localClusterInstances.set(newLocalClusterView.getInstances().size());
+
+ if (oldViewOrNull == null) {
+ localClusterJoins.addAndGet(newLocalClusterView.getInstances().size());
+ } else {
+ final ClusterView oldLocalClusterView = oldViewOrNull.getLocalInstance().getClusterView();
+ final InstancesDiff diff = new InstancesDiff(oldLocalClusterView, newLocalClusterView);
+ final Collection<InstanceDescription> added = diff.added().get();
+ final Collection<InstanceDescription> removed = diff.removed().get();
+
+ if (added != null && added.size() > 0) {
Review comment:
`diff.added().get()` is annotated with Nonnull. The null check here is unnecessary.
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
Review comment:
Remove `oldView` because it is unused?
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[GitHub] [sling-org-apache-sling-discovery-support] stefan-egli commented on a change in pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
stefan-egli commented on a change in pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#discussion_r468710146
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
+ changingEvents.incrementAndGet();
+ topologyIsUndefined.set(1);
+ }
+
+ private void handleChanged(TopologyView oldView, TopologyView newView) {
+ changedEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(oldView, newView);
+
+ updateLeaderSwitch(oldView, newView);
+
+ updateProperties(newView);
+ updateRemote(newView);
+ }
+
+ private void handlePropertiesChanged(TopologyView oldView, TopologyView newView) {
Review comment:
agreed, can always add it back if needed later, removed now.
##########
File path: src/main/java/org/apache/sling/discovery/impl/support/MetricReporter.java
##########
@@ -0,0 +1,429 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.sling.discovery.impl.support;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.Service;
+import org.apache.sling.discovery.ClusterView;
+import org.apache.sling.discovery.InstanceDescription;
+import org.apache.sling.discovery.TopologyEvent;
+import org.apache.sling.discovery.TopologyEventListener;
+import org.apache.sling.discovery.TopologyView;
+import org.apache.sling.discovery.commons.InstancesDiff;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.MetricRegistry;
+
+/**
+ * MetricReporter is in charge of listening to TopologyEvents
+ * (by virtue of being a TopologyEventListener) and exposing
+ * metrics (via dropwizard).
+ */
+@Service(value = { TopologyEventListener.class })
+@Component(immediate = true)
+public class MetricReporter implements TopologyEventListener {
+
+ // event counters
+ static final String METRICS_NAME_TOPOLOGY_CHANGING_EVENTS = "discovery.oak.topology.changing.events";
+ static final String METRICS_NAME_TOPOLOGY_INIT_EVENTS = "discovery.oak.topology.init.events";
+ static final String METRICS_NAME_TOPOLOGY_CHANGED_EVENTS = "discovery.oak.topology.changed.events";
+ static final String METRICS_NAME_PROPERTY_CHANGED_EVENTS = "discovery.oak.property.changed.events";
+
+ static final String METRICS_NAME_TOPOLOGY_IS_UNDEFINED = "discovery.oak.topology.is.undefined";
+
+ static final String METRICS_NAME_LOCAL_CLUSTER_INSTANCES = "discovery.oak.local.cluster.instances";
+ static final String METRICS_NAME_LOCAL_CLUSTER_JOINS = "discovery.oak.local.cluster.joins";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEAVES = "discovery.oak.local.cluster.leaves";
+ static final String METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES = "discovery.oak.local.cluster.leader.switches";
+ static final String METRICS_NAME_LOCAL_CLUSTER_PROPERTIES = "discovery.oak.local.cluster.properties";
+
+ static final String METRICS_NAME_OWN_IS_LEADER = "discovery.oak.own.is.leader";
+ static final String METRICS_NAME_OWN_PROPERTIES = "discovery.oak.own.properties";
+
+ static final String METRICS_NAME_REMOTE_CLUSTERS = "discovery.oak.remote.cluster";
+ static final String METRICS_NAME_REMOTE_INSTANCES = "discovery.oak.remote.instances";
+
+ private final Logger logger = LoggerFactory.getLogger(getClass());
+
+ @Reference(target = "(name=sling)")
+ MetricRegistry metricRegistry;
+
+ private final List<String> registeredGaugeNameList = new LinkedList<String>();
+
+ /**
+ * for init there would really only be 2 values needed: 0 and 1
+ * as there should only ever be 1 TOPOLOGY_INIT event.
+ * But for monitoring reasons it might be interesting to use a
+ * counter here nevertheless and ensure that it never goes above 1.
+ */
+ private final AtomicInteger initEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGING events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changingEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events. An int should be enough,
+ * if there is 1 event per second this lasts 68 years
+ */
+ private final AtomicInteger changedEvents = new AtomicInteger(0);
+
+ /**
+ * counts number of TOPOLOGY_CHANGED events.
+ * With a long if there is 1 event per millisecond it lasts 292471208 years
+ */
+ private final AtomicLong propertyChangedEvents = new AtomicLong(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that if the topology is undefined the localLeader is also undefined
+ * (but still represents the previous value).
+ * This one starts off as 1 until TOPOLOGY_INIT is received.
+ */
+ private final AtomicInteger topologyIsUndefined = new AtomicInteger(1);
+
+ /**
+ * Keeps track of number of instances in local cluster.
+ * There should really only be a small number, but even so an int is certainly enough.
+ */
+ private final AtomicInteger localClusterInstances = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that joined the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances joining per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterJoins = new AtomicInteger(0);
+
+ /**
+ * Counts the number of instances that left the local cluster, over time.
+ * The order of magnitude is number of TOPOLOGY_CHANGED events multiplied
+ * by number of instances leaving per such event. Still, an int sounds more than enough.
+ */
+ private final AtomicInteger localClusterLeaves = new AtomicInteger(0);
+
+ /**
+ * The number of leader changes should be smaller or equal to
+ * TOPOLOGY_CHANGED events +1.
+ * So an int seems more than enough.
+ * Note that this counts only actual changes, not a leader being announced via TOPOLOGY_INIT.
+ */
+ private final AtomicInteger localClusterLeaderSwitches = new AtomicInteger(0);
+
+ /**
+ * The order of magnitude here is number of properties multiplied by number of instances in the local cluster.
+ * So this is an order of magnitude higher than ownPropertiesCount -
+ * but still, an int should be enough, really.
+ */
+ private final AtomicInteger localClusterProperties = new AtomicInteger(0);
+
+ /**
+ * This is either 0 or 1 - but since the Gauge should be as fast as possible
+ * we maintain an int.
+ * Note that localLeader is only valid if the topology is not changing currently
+ * (otherwise it is undefined).
+ */
+ private final AtomicInteger ownIsLeader = new AtomicInteger(0);
+
+ /**
+ * There shouldn't be an aweful lot of properties, so int sounds more than enough
+ */
+ private final AtomicInteger ownProperties = new AtomicInteger(0);
+
+ /**
+ * Attached/remote clusters aren't probably too many, so again, int is enough
+ */
+ private final AtomicInteger remoteClusters = new AtomicInteger(0);
+
+ /**
+ * Attached/remote instances (sum of instances in remote clusters) -
+ * probably aren't too many, int is enough
+ */
+ private final AtomicInteger remoteInstances = new AtomicInteger(0);
+
+ @Activate
+ protected void activate() {
+ logger.debug("activate: start");
+
+ createGauge(METRICS_NAME_TOPOLOGY_INIT_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return initEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGING_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changingEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_CHANGED_EVENTS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return changedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_PROPERTY_CHANGED_EVENTS, new Gauge<Long>() {
+ @Override
+ public Long getValue() {
+ return propertyChangedEvents.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_TOPOLOGY_IS_UNDEFINED, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return topologyIsUndefined.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterInstances.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_JOINS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterJoins.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEAVES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaves.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_LEADER_SWITCHES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterLeaderSwitches.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_LOCAL_CLUSTER_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return localClusterProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_IS_LEADER, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownIsLeader.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_OWN_PROPERTIES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return ownProperties.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_CLUSTERS, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteClusters.get();
+ }
+ });
+
+ createGauge(METRICS_NAME_REMOTE_INSTANCES, new Gauge<Integer>() {
+ @Override
+ public Integer getValue() {
+ return remoteInstances.get();
+ }
+ });
+
+ logger.info("activate: done.");
+ }
+
+ @SuppressWarnings("rawtypes")
+ private void createGauge(String gaugeName, Gauge gauge) {
+ logger.debug("createGauge: registering gauge : " + gaugeName);
+ this.metricRegistry.register(gaugeName, gauge);
+ registeredGaugeNameList.add(gaugeName);
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ logger.debug("deactivate: deactivating.");
+ unregisterGauges();
+ logger.info("deactivate: done.");
+ }
+
+ private void unregisterGauges() {
+ for (String registeredGaugeName : registeredGaugeNameList) {
+ logger.debug("unregisterGauges : unregistering gauge : " + registeredGaugeName);
+ metricRegistry.remove(registeredGaugeName);
+ }
+ }
+
+ @Override
+ public void handleTopologyEvent(TopologyEvent event) {
+ if (event == null) {
+ // this should not occur
+ return;
+ }
+
+ try {
+ switch (event.getType()) {
+ case TOPOLOGY_INIT: {
+ handleInit(event.getNewView());
+ return;
+ }
+ case TOPOLOGY_CHANGING: {
+ handleChanging(event.getOldView());
+ return;
+ }
+ case TOPOLOGY_CHANGED: {
+ handleChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ case PROPERTIES_CHANGED: {
+ handlePropertiesChanged(event.getOldView(), event.getNewView());
+ return;
+ }
+ }
+ } catch (Exception e) {
+ // we should not really see any of those, but just in case..:
+ logger.error("handleTopologyEvent: got Exception " + e, e);
+ }
+ }
+
+ private void handleInit(TopologyView newView) {
+ initEvents.incrementAndGet();
+ topologyIsUndefined.set(0);
+
+ updateLocalClusterInstances(null, newView);
+
+ updateProperties(newView);
+ updateOwnIsLeader(newView);
+ updateRemote(newView);
+ }
+
+ private void handleChanging(TopologyView oldView) {
Review comment:
agreed, can always add it back if needed later, removed now.
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[GitHub] [sling-org-apache-sling-discovery-support] stefan-egli commented on pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
stefan-egli commented on pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#issuecomment-672073971
Thx @mreutegg for the review, I've applied all findings, incl
> Did you consider using Sling Metrics instead of introducing a dependency to dropwizard directly?
yea, I agree, it's nicer to depend on sling.commons.metrics, done that now [here](https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1/commits/ae26769f02134aabedada3dcfe5dbf3ed5e64132)
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[GitHub] [sling-org-apache-sling-discovery-support] sonarcloud[bot] commented on pull request #1: SLING-9589 : expose discovery metrics
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URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#issuecomment-671536663
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[GitHub] [sling-org-apache-sling-discovery-support] sonarcloud[bot] commented on pull request #1: SLING-9589 : expose discovery metrics
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sonarcloud[bot] commented on pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#issuecomment-672091044
Kudos, SonarCloud Quality Gate passed!
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[GitHub] [sling-org-apache-sling-discovery-support] sonarcloud[bot] commented on pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
sonarcloud[bot] commented on pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#issuecomment-672094905
Kudos, SonarCloud Quality Gate passed!
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[GitHub] [sling-org-apache-sling-discovery-support] sonarcloud[bot] commented on pull request #1: SLING-9589 : expose discovery metrics
Posted by GitBox <gi...@apache.org>.
sonarcloud[bot] commented on pull request #1:
URL: https://github.com/apache/sling-org-apache-sling-discovery-support/pull/1#issuecomment-658877784
Kudos, SonarCloud Quality Gate passed!
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<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/common/message_warning.png' alt='warning' width='16' height='16' /> The version of Java (1.8.0_252) you have used to run this analysis is deprecated and we will stop accepting it from October 2020. Please update to at least Java 11.
Read more [here](https://sonarcloud.io/documentation/upcoming/)
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