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Posted to reviews@helix.apache.org by GitBox <gi...@apache.org> on 2020/12/21 23:35:05 UTC
[GitHub] [helix] xyuanlu commented on a change in pull request #1532: Per replica throttle
xyuanlu commented on a change in pull request #1532:
URL: https://github.com/apache/helix/pull/1532#discussion_r546984789
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File path: helix-core/src/main/java/org/apache/helix/controller/stages/PerReplicaThrottleStage.java
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@@ -0,0 +1,956 @@
+package org.apache.helix.controller.stages;
+
+/*
+ * 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.
+ */
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.helix.HelixDefinedState;
+import org.apache.helix.HelixException;
+import org.apache.helix.HelixManager;
+import org.apache.helix.api.config.StateTransitionThrottleConfig;
+import org.apache.helix.controller.LogUtil;
+import org.apache.helix.controller.common.PartitionStateMap;
+import org.apache.helix.controller.common.ResourcesStateMap;
+import org.apache.helix.controller.dataproviders.ResourceControllerDataProvider;
+import org.apache.helix.controller.pipeline.AbstractBaseStage;
+import org.apache.helix.controller.pipeline.StageException;
+import org.apache.helix.model.BuiltInStateModelDefinitions;
+import org.apache.helix.model.ClusterConfig;
+import org.apache.helix.model.IdealState;
+import org.apache.helix.model.MaintenanceSignal;
+import org.apache.helix.model.Message;
+import org.apache.helix.model.Partition;
+import org.apache.helix.model.Resource;
+import org.apache.helix.model.StateModelDefinition;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+public class PerReplicaThrottleStage extends AbstractBaseStage {
+ private static final Logger logger =
+ LoggerFactory.getLogger(PerReplicaThrottleStage.class.getName());
+
+ private boolean isEmitThrottledMsg = false;
+
+ public PerReplicaThrottleStage() {
+ this(false);
+ }
+
+ protected PerReplicaThrottleStage(boolean enableEmitThrottledMsg) {
+ isEmitThrottledMsg = enableEmitThrottledMsg;
+ }
+
+ @Override
+ public void process(ClusterEvent event) throws Exception {
+ _eventId = event.getEventId();
+
+ CurrentStateOutput currentStateOutput = event.getAttribute(AttributeName.CURRENT_STATE.name());
+
+ MessageOutput selectedMessages = event.getAttribute(AttributeName.MESSAGES_SELECTED.name());
+ LogUtil.logDebug(logger, _eventId, String.format("selectedMessages is: %s", selectedMessages));
+
+ Map<String, Resource> resourceToRebalance =
+ event.getAttribute(AttributeName.RESOURCES_TO_REBALANCE.name());
+ ResourceControllerDataProvider cache =
+ event.getAttribute(AttributeName.ControllerDataProvider.name());
+
+ if (currentStateOutput == null || selectedMessages == null || resourceToRebalance == null
+ || cache == null) {
+ throw new StageException(String.format("Missing attributes in event: %s. "
+ + "Requires CURRENT_STATE (%s) |BEST_POSSIBLE_STATE (%s) |RESOURCES (%s) |DataCache (%s)",
+ event, currentStateOutput, selectedMessages, resourceToRebalance, cache));
+ }
+
+ ResourcesStateMap retracedResourceStateMap = new ResourcesStateMap();
+ List<Message> throttledRecoveryMsg = new ArrayList<>();
+ List<Message> throttledLoadMsg = new ArrayList<>();
+ MessageOutput output =
+ compute(event, resourceToRebalance, currentStateOutput, selectedMessages, retracedResourceStateMap, throttledRecoveryMsg, throttledLoadMsg);
+
+ if (logger.isDebugEnabled()) {
+ LogUtil.logDebug(logger, _eventId, String.format("output is"));
+ for (String resource : resourceToRebalance.keySet()) {
+ if (output.getResourceMessages(resource) != null) {
+ LogUtil.logDebug(logger, _eventId, String.format("resource: %s", resource));
+ Map<Partition, List<Message>> partitionListMap = output.getResourceMessages(resource);
+ for (Partition partition : partitionListMap.keySet()) {
+ for (Message msg : partitionListMap.get(partition)) {
+ LogUtil.logDebug(logger, _eventId, String
+ .format("\tresource: %s, partition: %s, msg: %s", resource, partition, msg));
+ }
+ }
+ }
+ }
+ }
+ event.addAttribute(AttributeName.PER_REPLICA_OUTPUT_MESSAGES.name(), output);
+ LogUtil.logDebug(logger,_eventId, String.format("retraceResourceStateMap is: %s", retracedResourceStateMap));
+ event.addAttribute(AttributeName.PER_REPLICA_RETRACED_STATES.name(), retracedResourceStateMap);
+
+ if (isEmitThrottledMsg) {
+ event.addAttribute(AttributeName.PER_REPLICA_THROTTLED_RECOVERY_MESSAGES.name(), throttledRecoveryMsg);
+ event.addAttribute(AttributeName.PER_REPLICA_THOTTLED_LOAD_MESSAGES.name(), throttledLoadMsg);
+ }
+
+ // Make sure no instance has more replicas/partitions assigned than maxPartitionPerInstance. If
+ // it does, pause the rebalance and put the cluster on maintenance mode
+ int maxPartitionPerInstance = cache.getClusterConfig().getMaxPartitionsPerInstance();
+ if (maxPartitionPerInstance > 0) {
+ validateMaxPartitionsPerInstance(retracedResourceStateMap, maxPartitionPerInstance, cache, event);
+ }
+
+ //TODO: add metrics
+ }
+
+ /**
+ * Go through every instance in the assignment and check that each instance does NOT have more
+ * replicas for partitions assigned to it than maxPartitionsPerInstance. If the assignment
+ * violates this, put the cluster on maintenance mode.
+ * @param retracedResourceStateMap
+ * @param maxPartitionPerInstance
+ */
+ private void validateMaxPartitionsPerInstance(ResourcesStateMap retracedResourceStateMap,
+ int maxPartitionPerInstance, ResourceControllerDataProvider cache, ClusterEvent event) {
+ Map<String, PartitionStateMap> resourceStatesMap = retracedResourceStateMap.getResourceStatesMap();
+ Map<String, Integer> instancePartitionCounts = new HashMap<>();
+
+ for (String resource : resourceStatesMap.keySet()) {
+ IdealState idealState = cache.getIdealState(resource);
+ if (idealState != null
+ && idealState.getStateModelDefRef().equals(BuiltInStateModelDefinitions.Task.name())) {
+ // Ignore task here. Task has its own throttling logic
+ continue;
+ }
+
+ PartitionStateMap partitionStateMap = resourceStatesMap.get(resource);
+ Map<Partition, Map<String, String>> stateMaps = partitionStateMap.getStateMap();
+ for (Partition p : stateMaps.keySet()) {
+ Map<String, String> stateMap = stateMaps.get(p);
+ for (String instance : stateMap.keySet()) {
+ // If this replica is in DROPPED state, do not count it in the partition count since it is
+ // to be dropped
+ String state = stateMap.get(instance);
+ if (state.equals(HelixDefinedState.DROPPED.name())) {
+ continue;
+ }
+ if (!instancePartitionCounts.containsKey(instance)) {
+ instancePartitionCounts.put(instance, 0);
+ }
+ int partitionCount = instancePartitionCounts.get(instance);
+ // Number of replicas (from different partitions) held in this instance
+ partitionCount++;
+ if (partitionCount > maxPartitionPerInstance) {
+ HelixManager manager = event.getAttribute(AttributeName.helixmanager.name());
+ String errMsg = String.format(
+ "Problem: according to this assignment, instance %s contains more "
+ + "replicas/partitions than the maximum number allowed (%d). Pipeline will "
+ + "stop the rebalance and put the cluster %s into maintenance mode",
+ instance, maxPartitionPerInstance, cache.getClusterName());
+ if (manager != null) {
+ if (manager.getHelixDataAccessor()
+ .getProperty(manager.getHelixDataAccessor().keyBuilder().maintenance()) == null) {
+ manager.getClusterManagmentTool().autoEnableMaintenanceMode(
+ manager.getClusterName(), true, errMsg,
+ MaintenanceSignal.AutoTriggerReason.MAX_PARTITION_PER_INSTANCE_EXCEEDED);
+ }
+ LogUtil.logWarn(logger, _eventId, errMsg);
+ } else {
+ LogUtil.logError(logger, _eventId,
+ "HelixManager is not set/null! Failed to pause this cluster/enable maintenance"
+ + " mode due to an instance being assigned more replicas/partitions than "
+ + "the limit.");
+ }
+ throw new HelixException(errMsg);
+ }
+ instancePartitionCounts.put(instance, partitionCount);
+ }
+ }
+ }
+ }
+
+ /**
+ * Go through each resource, and based on messageSelected and currentState, compute
+ * messageOutput while maintaining throttling constraints (for example, ensure that the number
+ * of possible pending state transitions does NOT go over the set threshold).
+ * @param event
+ * @param resourceMap
+ * @param currentStateOutput
+ * @param selectedMessage
+ * @param retracedResourceStateMap out
+ * @return
+ */
+ private MessageOutput compute(ClusterEvent event, Map<String, Resource> resourceMap,
+ CurrentStateOutput currentStateOutput, MessageOutput selectedMessage,
+ ResourcesStateMap retracedResourceStateMap,
+ List<Message> throttledRecoveryMsg, List<Message> throttledLoadMsg) {
+ MessageOutput output = new MessageOutput();
+
+ ResourceControllerDataProvider dataCache =
+ event.getAttribute(AttributeName.ControllerDataProvider.name());
+
+ StateTransitionThrottleController throttleController =
+ new StateTransitionThrottleController(resourceMap.keySet(), dataCache.getClusterConfig(),
+ dataCache.getLiveInstances().keySet());
+
+ // Resource level prioritization based on the numerical (sortable) priority field.
+ // If the resource priority field is null/not set, the resource will be treated as lowest
+ // priority.
+ List<ResourcePriority> prioritizedResourceList = new ArrayList<>();
+ for (String resourceName : resourceMap.keySet()) {
+ prioritizedResourceList.add(new ResourcePriority(resourceName, Integer.MIN_VALUE));
+ }
+ // If resourcePriorityField is null at the cluster level, all resources will be considered equal
+ // in priority by keeping all priorities at MIN_VALUE
+ String priorityField = dataCache.getClusterConfig().getResourcePriorityField();
+ if (priorityField != null) {
+ for (ResourcePriority resourcePriority : prioritizedResourceList) {
+ String resourceName = resourcePriority.getResourceName();
+
+ // Will take the priority from ResourceConfig first
+ // If ResourceConfig does not exist or does not have this field.
+ // Try to load it from the resource's IdealState. Otherwise, keep it at the lowest priority
+ if (dataCache.getResourceConfig(resourceName) != null
+ && dataCache.getResourceConfig(resourceName).getSimpleConfig(priorityField) != null) {
+ resourcePriority.setPriority(
+ dataCache.getResourceConfig(resourceName).getSimpleConfig(priorityField));
+ } else if (dataCache.getIdealState(resourceName) != null
+ && dataCache.getIdealState(resourceName).getRecord().getSimpleField(priorityField)
+ != null) {
+ resourcePriority.setPriority(
+ dataCache.getIdealState(resourceName).getRecord().getSimpleField(priorityField));
+ }
+ }
+ prioritizedResourceList.sort(new ResourcePriorityComparator());
+ }
+
+ List<String> failedResources = new ArrayList<>();
+
+ // Priority is applied in assignment computation because higher priority by looping in order of
+ // decreasing priority
+ for (ResourcePriority resourcePriority : prioritizedResourceList) {
+ String resourceName = resourcePriority.getResourceName();
+
+ BestPossibleStateOutput bestPossibleStateOutput =
+ event.getAttribute(AttributeName.BEST_POSSIBLE_STATE.name());
+ if (!bestPossibleStateOutput.containsResource(resourceName)) {
+ LogUtil.logInfo(logger, _eventId, String.format(
+ "Skip calculating per replica state for resource %s because the best possible state is not available.",
+ resourceName));
+ continue;
+ }
+
+ Resource resource = resourceMap.get(resourceName);
+ IdealState idealState = dataCache.getIdealState(resourceName);
+ if (idealState == null) {
+ // If IdealState is null, use an empty one
+ LogUtil.logInfo(logger, _eventId, String
+ .format("IdealState for resource %s does not exist; resource may not exist anymore",
+ resourceName));
+ idealState = new IdealState(resourceName);
+ idealState.setStateModelDefRef(resource.getStateModelDefRef());
+ }
+
+ Map<Partition, Map<String, String>> retracedPartitionsState = new HashMap<>();
+ try {
+ throttlePerReplicaMessages(idealState, currentStateOutput,
+ selectedMessage.getResourceMessages(resourceName), resourceMap.get(resourceName),
+ bestPossibleStateOutput, dataCache, throttleController, retracedPartitionsState,
+ throttledRecoveryMsg, throttledLoadMsg, output);
+ retracedResourceStateMap.setState(resourceName, retracedPartitionsState);
+ } catch (HelixException ex) {
+ LogUtil.logInfo(logger, _eventId,
+ "Failed to calculate per replica partition states for resource " + resourceName, ex);
+ failedResources.add(resourceName);
+ }
+ }
+
+ return output;
+ }
+
+ /*
+ * Apply per-replica throttling logic and filter out excessive recovery and load messages for a
+ * given resource.
+ * Reconstruct retrace partition states for a resource based on pending and targeted messages
+ * Return messages for partitions of a resource.
+ * Out param retracedPartitionsCurrentState
+ * Out param output
+ */
+ private void throttlePerReplicaMessages(IdealState idealState,
+ CurrentStateOutput currentStateOutput, Map<Partition, List<Message>> selectedResourceMessages,
+ Resource resource, BestPossibleStateOutput bestPossibleStateOutput,
+ ResourceControllerDataProvider cache, StateTransitionThrottleController throttleController,
+ Map<Partition, Map<String, String>> retracedPartitionsStateMap,
+ List<Message> throttledRecoveryMsgOut, List<Message> throttledLoadMessageOut,
+ MessageOutput output) {
+ String resourceName = resource.getResourceName();
+ LogUtil.logInfo(logger, _eventId, String.format("Processing resource: %s", resourceName));
+
+ if (!throttleController.isThrottleEnabled() || !IdealState.RebalanceMode.FULL_AUTO
+ .equals(idealState.getRebalanceMode())) {
+ retracedPartitionsStateMap.putAll(bestPossibleStateOutput.getPartitionStateMap(resourceName).getStateMap());
+ for (Partition partition : selectedResourceMessages.keySet()) {
+ output.addMessages(resourceName, partition, selectedResourceMessages.get(partition));
+ }
+ return;
+ }
+ Map<String, List<String>> preferenceLists =
+ bestPossibleStateOutput.getPreferenceLists(resourceName);
+
+ Set<Partition> partitionsWithErrorStateReplica = new HashSet<>();
+ Set<Partition> partitionsNeedRecovery = new HashSet<>();
+
+ // Step 1: charge existing pending messages and update retraced state map.
+ chargePendingMessages(resource, throttleController, currentStateOutput, bestPossibleStateOutput,
+ idealState, cache, partitionsNeedRecovery, partitionsWithErrorStateReplica,
+ retracedPartitionsStateMap);
+
+ // Step 2: classify all the messages into recovery message list and load message list
+ List<Message> recoveryMessages = new ArrayList<>();
+ List<Message> loadMessages = new ArrayList<>();
+ Map<Message, Partition> messagePartitionMap = new HashMap<>(); // todo: Message may need a hashcode()
+ classifyMessages(resource, currentStateOutput, bestPossibleStateOutput, idealState, cache,
+ selectedResourceMessages, recoveryMessages, loadMessages, messagePartitionMap);
+
+ // Step 3: sorts recovery message list and applies throttling
+ Set<Message> throttledRecoveryMessages = new HashSet<>();
+
+ Map<Partition, Map<String, String>> bestPossibleMap =
+ bestPossibleStateOutput.getPartitionStateMap(resourceName).getStateMap();
+ Map<Partition, Map<String, String>> currentStateMap =
+ currentStateOutput.getCurrentStateMap(resourceName);
+ String stateModelDefName = idealState.getStateModelDefRef();
+ StateModelDefinition stateModelDef = cache.getStateModelDef(stateModelDefName);
+ LogUtil.logDebug(logger, _eventId,
+ String.format("applying recovery rebalance with resource %s", resourceName));
+ applyThrottling(resource, throttleController, currentStateMap, bestPossibleMap, idealState,
+ cache, false, recoveryMessages, messagePartitionMap,
+ throttledRecoveryMessages, StateTransitionThrottleConfig.RebalanceType.RECOVERY_BALANCE);
+
+ // Step 4: sorts load message list and applies throttling
+
+ // calculate error-on-recovery downward flag
+ // If the threshold (ErrorOrRecovery) is set, then use it, if not, then check if the old
+ // threshold (Error) is set. If the old threshold is set, use it. If not, use the default value
+ // for the new one. This is for backward-compatibility
+ int threshold = 1; // Default threshold for ErrorOrRecoveryPartitionThresholdForLoadBalance
Review comment:
I think it could be simplified into
if....else if ....else.
And we don't need he nested if here.
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