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Posted to commits@pulsar.apache.org by GitBox <gi...@apache.org> on 2022/06/30 18:13:18 UTC
[GitHub] [pulsar] heesung-sn commented on a diff in pull request #16281: [feature][broker]Provide new load balance placement strategy implementation based on the least resource usage with weight
heesung-sn commented on code in PR #16281:
URL: https://github.com/apache/pulsar/pull/16281#discussion_r911306976
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
+ private static Logger log = LoggerFactory.getLogger(LeastResourceUsageWithWeight.class);
+
+ // Maintain this list to reduce object creation.
+ private final ArrayList<String> bestBrokers;
+ private final Map<String, Double> brokerAvgResourceUsageWithWeight;
+
+ public LeastResourceUsageWithWeight() {
+ this.bestBrokers = new ArrayList<>();
+ this.brokerAvgResourceUsageWithWeight = new HashMap<>();
+ }
+
+ // Form a score for a broker using its historical load and short-term load data with weight.
+ // Any broker at (or above) the overload threshold will have a score of POSITIVE_INFINITY.
+ private double getScore(final String broker, final BrokerData brokerData, final ServiceConfiguration conf) {
+ final double overloadThresholdPercentage = conf.getLoadBalancerBrokerOverloadedThresholdPercentage();
+ final double maxUsageWithWeightPercentage =
+ updateAndGetMaxResourceUsageWithWeight(broker, brokerData, conf) * 100;
+
+ if (maxUsageWithWeightPercentage > overloadThresholdPercentage) {
+ log.warn("Broker {} is overloaded: max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ return Double.POSITIVE_INFINITY;
+ }
+
+ if (log.isDebugEnabled()) {
+ log.debug("Broker {} has max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ }
+ return maxUsageWithWeightPercentage;
+ }
+
+ /**
+ * Update and get the max resource usage with weight of broker according to the service configuration.
+ *
+ * @param broker the broker name.
+ * @param brokerData The broker load data.
+ * @param conf The service configuration.
+ * @return the max resource usage with weight of broker
+ */
+ private double updateAndGetMaxResourceUsageWithWeight(String broker, BrokerData brokerData,
+ ServiceConfiguration conf) {
+ final double historyPercentage = conf.getLoadBalancerHistoryResourcePercentage();
+ Double historyUsage = brokerAvgResourceUsageWithWeight.get(broker);
+ double resourceUsage = brokerData.getLocalData().getMaxResourceUsageWithWeight(
+ conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(),
+ conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ historyUsage = historyUsage == null
+ ? resourceUsage : historyUsage * historyPercentage + (1 - historyPercentage) * resourceUsage;
+ if (log.isDebugEnabled()) {
+ log.debug(
+ "Broker {} get max resource usage with weight: {}, history resource percentage: {}%, CPU weight: "
+ + "{}, MEMORY weight: {}, DIRECT MEMORY weight: {}, BANDWIDTH IN weight: {}, BANDWIDTH "
+ + "OUT weight: {} ",
+ broker, historyUsage, historyPercentage, conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ brokerAvgResourceUsageWithWeight.put(broker, historyUsage);
+ return historyUsage;
+ }
+
+ /**
+ * Find a suitable broker to assign the given bundle to.
+ *
+ * @param candidates The candidates for which the bundle may be assigned.
+ * @param bundleToAssign The data for the bundle to assign.
+ * @param loadData The load data from the leader broker.
+ * @param conf The service configuration.
+ * @return The name of the selected broker as it appears on ZooKeeper.
+ */
+ @Override
+ public Optional<String> selectBroker(Set<String> candidates, BundleData bundleToAssign, LoadData loadData,
+ ServiceConfiguration conf) {
+ bestBrokers.clear();
+ double minScore = Double.POSITIVE_INFINITY;
+ // Maintain of list of all the best scoring brokers and then randomly
+ // select one of them at the end.
+
+ for (String broker : candidates) {
+ final BrokerData brokerData = loadData.getBrokerData().get(broker);
+ final double score = getScore(broker, brokerData, conf);
+ if (score == Double.POSITIVE_INFINITY) {
+ final LocalBrokerData localData = brokerData.getLocalData();
+ log.warn(
+ "Broker {} is overloaded: CPU: {}%, MEMORY: {}%, DIRECT MEMORY: {}%, BANDWIDTH IN: {}%, "
+ + "BANDWIDTH OUT: {}%, CPU weight: {}, MEMORY weight: {}, DIRECT MEMORY weight: {}, "
+ + "BANDWIDTH IN weight: {}, BANDWIDTH OUT weight: {}",
+ broker, localData.getCpu().percentUsage(), localData.getMemory().percentUsage(),
+ localData.getDirectMemory().percentUsage(), localData.getBandwidthIn().percentUsage(),
+ localData.getBandwidthOut().percentUsage(), conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ if (score < minScore) {
+ bestBrokers.clear();
Review Comment:
Here, one of the edge cases I could think of is that the least loaded broker will be repeatedly selected until the broker load is updated to the leader.
I am wondering if filling `bestBrokers` only with `minScore` brokers is too much limiting the randomization pool.
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
+ private static Logger log = LoggerFactory.getLogger(LeastResourceUsageWithWeight.class);
+
+ // Maintain this list to reduce object creation.
+ private final ArrayList<String> bestBrokers;
+ private final Map<String, Double> brokerAvgResourceUsageWithWeight;
+
+ public LeastResourceUsageWithWeight() {
+ this.bestBrokers = new ArrayList<>();
+ this.brokerAvgResourceUsageWithWeight = new HashMap<>();
+ }
+
+ // Form a score for a broker using its historical load and short-term load data with weight.
+ // Any broker at (or above) the overload threshold will have a score of POSITIVE_INFINITY.
+ private double getScore(final String broker, final BrokerData brokerData, final ServiceConfiguration conf) {
+ final double overloadThresholdPercentage = conf.getLoadBalancerBrokerOverloadedThresholdPercentage();
+ final double maxUsageWithWeightPercentage =
+ updateAndGetMaxResourceUsageWithWeight(broker, brokerData, conf) * 100;
+
+ if (maxUsageWithWeightPercentage > overloadThresholdPercentage) {
+ log.warn("Broker {} is overloaded: max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ return Double.POSITIVE_INFINITY;
+ }
+
+ if (log.isDebugEnabled()) {
+ log.debug("Broker {} has max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ }
+ return maxUsageWithWeightPercentage;
+ }
+
+ /**
+ * Update and get the max resource usage with weight of broker according to the service configuration.
+ *
+ * @param broker the broker name.
+ * @param brokerData The broker load data.
+ * @param conf The service configuration.
+ * @return the max resource usage with weight of broker
+ */
+ private double updateAndGetMaxResourceUsageWithWeight(String broker, BrokerData brokerData,
+ ServiceConfiguration conf) {
+ final double historyPercentage = conf.getLoadBalancerHistoryResourcePercentage();
+ Double historyUsage = brokerAvgResourceUsageWithWeight.get(broker);
+ double resourceUsage = brokerData.getLocalData().getMaxResourceUsageWithWeight(
+ conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(),
+ conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ historyUsage = historyUsage == null
+ ? resourceUsage : historyUsage * historyPercentage + (1 - historyPercentage) * resourceUsage;
+ if (log.isDebugEnabled()) {
+ log.debug(
+ "Broker {} get max resource usage with weight: {}, history resource percentage: {}%, CPU weight: "
+ + "{}, MEMORY weight: {}, DIRECT MEMORY weight: {}, BANDWIDTH IN weight: {}, BANDWIDTH "
+ + "OUT weight: {} ",
+ broker, historyUsage, historyPercentage, conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ brokerAvgResourceUsageWithWeight.put(broker, historyUsage);
+ return historyUsage;
+ }
+
+ /**
+ * Find a suitable broker to assign the given bundle to.
+ *
+ * @param candidates The candidates for which the bundle may be assigned.
+ * @param bundleToAssign The data for the bundle to assign.
+ * @param loadData The load data from the leader broker.
+ * @param conf The service configuration.
+ * @return The name of the selected broker as it appears on ZooKeeper.
+ */
+ @Override
+ public Optional<String> selectBroker(Set<String> candidates, BundleData bundleToAssign, LoadData loadData,
+ ServiceConfiguration conf) {
+ bestBrokers.clear();
+ double minScore = Double.POSITIVE_INFINITY;
+ // Maintain of list of all the best scoring brokers and then randomly
+ // select one of them at the end.
+
+ for (String broker : candidates) {
+ final BrokerData brokerData = loadData.getBrokerData().get(broker);
+ final double score = getScore(broker, brokerData, conf);
+ if (score == Double.POSITIVE_INFINITY) {
+ final LocalBrokerData localData = brokerData.getLocalData();
+ log.warn(
+ "Broker {} is overloaded: CPU: {}%, MEMORY: {}%, DIRECT MEMORY: {}%, BANDWIDTH IN: {}%, "
+ + "BANDWIDTH OUT: {}%, CPU weight: {}, MEMORY weight: {}, DIRECT MEMORY weight: {}, "
+ + "BANDWIDTH IN weight: {}, BANDWIDTH OUT weight: {}",
+ broker, localData.getCpu().percentUsage(), localData.getMemory().percentUsage(),
+ localData.getDirectMemory().percentUsage(), localData.getBandwidthIn().percentUsage(),
+ localData.getBandwidthOut().percentUsage(), conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ if (score < minScore) {
+ bestBrokers.clear();
+ bestBrokers.add(broker);
+ minScore = score;
+ } else if (score == minScore) {
+ bestBrokers.add(broker);
+ }
+ }
+ if (bestBrokers.isEmpty()) {
+ // Assign randomly if all brokers are overloaded.
+ bestBrokers.addAll(candidates);
+ }
+
+ if (bestBrokers.isEmpty()) {
+ // If still, it means there are no available brokers at this point.
Review Comment:
Please add a warn log here. (e.g. `candidates` is empty)
##########
conf/broker.conf:
##########
@@ -1171,6 +1171,9 @@ defaultNamespaceBundleSplitAlgorithm=range_equally_divide
# load shedding strategy, support OverloadShedder and ThresholdShedder, default is ThresholdShedder since 2.10.0
loadBalancerLoadSheddingStrategy=org.apache.pulsar.broker.loadbalance.impl.ThresholdShedder
+# load balance placement strategy, support LeastLongTermMessageRate and LeastResourceUsageWithWeight
+loadBalancerLoadPlacementStrategy=org.apache.pulsar.broker.loadbalance.impl.LeastLongTermMessageRate
Review Comment:
To me, `LeastResourceUsageWithWeight` looks better than `LeastLongTermMessageRate`. What is our plan to make `LeastResourceUsageWithWeight` as the default?
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
+ private static Logger log = LoggerFactory.getLogger(LeastResourceUsageWithWeight.class);
+
+ // Maintain this list to reduce object creation.
+ private final ArrayList<String> bestBrokers;
+ private final Map<String, Double> brokerAvgResourceUsageWithWeight;
+
+ public LeastResourceUsageWithWeight() {
+ this.bestBrokers = new ArrayList<>();
+ this.brokerAvgResourceUsageWithWeight = new HashMap<>();
+ }
+
+ // Form a score for a broker using its historical load and short-term load data with weight.
+ // Any broker at (or above) the overload threshold will have a score of POSITIVE_INFINITY.
+ private double getScore(final String broker, final BrokerData brokerData, final ServiceConfiguration conf) {
+ final double overloadThresholdPercentage = conf.getLoadBalancerBrokerOverloadedThresholdPercentage();
+ final double maxUsageWithWeightPercentage =
+ updateAndGetMaxResourceUsageWithWeight(broker, brokerData, conf) * 100;
+
+ if (maxUsageWithWeightPercentage > overloadThresholdPercentage) {
+ log.warn("Broker {} is overloaded: max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ return Double.POSITIVE_INFINITY;
+ }
+
+ if (log.isDebugEnabled()) {
+ log.debug("Broker {} has max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ }
+ return maxUsageWithWeightPercentage;
+ }
+
+ /**
+ * Update and get the max resource usage with weight of broker according to the service configuration.
+ *
+ * @param broker the broker name.
+ * @param brokerData The broker load data.
+ * @param conf The service configuration.
+ * @return the max resource usage with weight of broker
+ */
+ private double updateAndGetMaxResourceUsageWithWeight(String broker, BrokerData brokerData,
+ ServiceConfiguration conf) {
+ final double historyPercentage = conf.getLoadBalancerHistoryResourcePercentage();
+ Double historyUsage = brokerAvgResourceUsageWithWeight.get(broker);
+ double resourceUsage = brokerData.getLocalData().getMaxResourceUsageWithWeight(
+ conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(),
+ conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ historyUsage = historyUsage == null
+ ? resourceUsage : historyUsage * historyPercentage + (1 - historyPercentage) * resourceUsage;
+ if (log.isDebugEnabled()) {
+ log.debug(
+ "Broker {} get max resource usage with weight: {}, history resource percentage: {}%, CPU weight: "
+ + "{}, MEMORY weight: {}, DIRECT MEMORY weight: {}, BANDWIDTH IN weight: {}, BANDWIDTH "
+ + "OUT weight: {} ",
+ broker, historyUsage, historyPercentage, conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ brokerAvgResourceUsageWithWeight.put(broker, historyUsage);
+ return historyUsage;
+ }
+
+ /**
+ * Find a suitable broker to assign the given bundle to.
+ *
+ * @param candidates The candidates for which the bundle may be assigned.
+ * @param bundleToAssign The data for the bundle to assign.
+ * @param loadData The load data from the leader broker.
+ * @param conf The service configuration.
+ * @return The name of the selected broker as it appears on ZooKeeper.
+ */
+ @Override
+ public Optional<String> selectBroker(Set<String> candidates, BundleData bundleToAssign, LoadData loadData,
+ ServiceConfiguration conf) {
+ bestBrokers.clear();
+ double minScore = Double.POSITIVE_INFINITY;
+ // Maintain of list of all the best scoring brokers and then randomly
+ // select one of them at the end.
+
+ for (String broker : candidates) {
+ final BrokerData brokerData = loadData.getBrokerData().get(broker);
+ final double score = getScore(broker, brokerData, conf);
+ if (score == Double.POSITIVE_INFINITY) {
+ final LocalBrokerData localData = brokerData.getLocalData();
+ log.warn(
+ "Broker {} is overloaded: CPU: {}%, MEMORY: {}%, DIRECT MEMORY: {}%, BANDWIDTH IN: {}%, "
+ + "BANDWIDTH OUT: {}%, CPU weight: {}, MEMORY weight: {}, DIRECT MEMORY weight: {}, "
+ + "BANDWIDTH IN weight: {}, BANDWIDTH OUT weight: {}",
+ broker, localData.getCpu().percentUsage(), localData.getMemory().percentUsage(),
+ localData.getDirectMemory().percentUsage(), localData.getBandwidthIn().percentUsage(),
+ localData.getBandwidthOut().percentUsage(), conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ if (score < minScore) {
+ bestBrokers.clear();
+ bestBrokers.add(broker);
+ minScore = score;
+ } else if (score == minScore) {
+ bestBrokers.add(broker);
+ }
+ }
+ if (bestBrokers.isEmpty()) {
+ // Assign randomly if all brokers are overloaded.
Review Comment:
Please add a warn log here.
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
Review Comment:
I think this logic is similar to(conflicting with) https://github.com/apache/pulsar/pull/14971, which is in PR.
Could you communicate with the author, @[dragonls](https://github.com/dragonls) and decide which one to pursue?
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
+ private static Logger log = LoggerFactory.getLogger(LeastResourceUsageWithWeight.class);
+
+ // Maintain this list to reduce object creation.
+ private final ArrayList<String> bestBrokers;
+ private final Map<String, Double> brokerAvgResourceUsageWithWeight;
+
+ public LeastResourceUsageWithWeight() {
+ this.bestBrokers = new ArrayList<>();
+ this.brokerAvgResourceUsageWithWeight = new HashMap<>();
+ }
+
+ // Form a score for a broker using its historical load and short-term load data with weight.
+ // Any broker at (or above) the overload threshold will have a score of POSITIVE_INFINITY.
+ private double getScore(final String broker, final BrokerData brokerData, final ServiceConfiguration conf) {
+ final double overloadThresholdPercentage = conf.getLoadBalancerBrokerOverloadedThresholdPercentage();
+ final double maxUsageWithWeightPercentage =
+ updateAndGetMaxResourceUsageWithWeight(broker, brokerData, conf) * 100;
+
+ if (maxUsageWithWeightPercentage > overloadThresholdPercentage) {
+ log.warn("Broker {} is overloaded: max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ return Double.POSITIVE_INFINITY;
+ }
+
+ if (log.isDebugEnabled()) {
+ log.debug("Broker {} has max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ }
+ return maxUsageWithWeightPercentage;
+ }
+
+ /**
+ * Update and get the max resource usage with weight of broker according to the service configuration.
+ *
+ * @param broker the broker name.
+ * @param brokerData The broker load data.
+ * @param conf The service configuration.
+ * @return the max resource usage with weight of broker
+ */
+ private double updateAndGetMaxResourceUsageWithWeight(String broker, BrokerData brokerData,
+ ServiceConfiguration conf) {
+ final double historyPercentage = conf.getLoadBalancerHistoryResourcePercentage();
+ Double historyUsage = brokerAvgResourceUsageWithWeight.get(broker);
+ double resourceUsage = brokerData.getLocalData().getMaxResourceUsageWithWeight(
+ conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(),
+ conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ historyUsage = historyUsage == null
+ ? resourceUsage : historyUsage * historyPercentage + (1 - historyPercentage) * resourceUsage;
+ if (log.isDebugEnabled()) {
+ log.debug(
+ "Broker {} get max resource usage with weight: {}, history resource percentage: {}%, CPU weight: "
+ + "{}, MEMORY weight: {}, DIRECT MEMORY weight: {}, BANDWIDTH IN weight: {}, BANDWIDTH "
+ + "OUT weight: {} ",
+ broker, historyUsage, historyPercentage, conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ brokerAvgResourceUsageWithWeight.put(broker, historyUsage);
+ return historyUsage;
+ }
+
+ /**
+ * Find a suitable broker to assign the given bundle to.
+ *
+ * @param candidates The candidates for which the bundle may be assigned.
+ * @param bundleToAssign The data for the bundle to assign.
+ * @param loadData The load data from the leader broker.
+ * @param conf The service configuration.
+ * @return The name of the selected broker as it appears on ZooKeeper.
+ */
+ @Override
+ public Optional<String> selectBroker(Set<String> candidates, BundleData bundleToAssign, LoadData loadData,
+ ServiceConfiguration conf) {
+ bestBrokers.clear();
Review Comment:
nit: please mention that this is not thread-safe.
##########
pulsar-broker/src/main/java/org/apache/pulsar/broker/loadbalance/impl/LeastResourceUsageWithWeight.java:
##########
@@ -0,0 +1,159 @@
+/**
+ * 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.pulsar.broker.loadbalance.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.loadbalance.LoadData;
+import org.apache.pulsar.broker.loadbalance.ModularLoadManagerStrategy;
+import org.apache.pulsar.policies.data.loadbalancer.BrokerData;
+import org.apache.pulsar.policies.data.loadbalancer.BundleData;
+import org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Placement strategy which selects a broker based on which one has the least resource usage with weight.
+ * This strategy takes into account the historical load percentage and short-term load percentage, and thus will not
+ * cause cluster fluctuations due to short-term load jitter.
+ */
+public class LeastResourceUsageWithWeight implements ModularLoadManagerStrategy {
+ private static Logger log = LoggerFactory.getLogger(LeastResourceUsageWithWeight.class);
+
+ // Maintain this list to reduce object creation.
+ private final ArrayList<String> bestBrokers;
+ private final Map<String, Double> brokerAvgResourceUsageWithWeight;
+
+ public LeastResourceUsageWithWeight() {
+ this.bestBrokers = new ArrayList<>();
+ this.brokerAvgResourceUsageWithWeight = new HashMap<>();
+ }
+
+ // Form a score for a broker using its historical load and short-term load data with weight.
+ // Any broker at (or above) the overload threshold will have a score of POSITIVE_INFINITY.
+ private double getScore(final String broker, final BrokerData brokerData, final ServiceConfiguration conf) {
+ final double overloadThresholdPercentage = conf.getLoadBalancerBrokerOverloadedThresholdPercentage();
+ final double maxUsageWithWeightPercentage =
+ updateAndGetMaxResourceUsageWithWeight(broker, brokerData, conf) * 100;
+
+ if (maxUsageWithWeightPercentage > overloadThresholdPercentage) {
+ log.warn("Broker {} is overloaded: max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ return Double.POSITIVE_INFINITY;
+ }
+
+ if (log.isDebugEnabled()) {
+ log.debug("Broker {} has max resource usage with weight percentage: {}%",
+ brokerData.getLocalData().getWebServiceUrl(), maxUsageWithWeightPercentage);
+ }
+ return maxUsageWithWeightPercentage;
+ }
+
+ /**
+ * Update and get the max resource usage with weight of broker according to the service configuration.
+ *
+ * @param broker the broker name.
+ * @param brokerData The broker load data.
+ * @param conf The service configuration.
+ * @return the max resource usage with weight of broker
+ */
+ private double updateAndGetMaxResourceUsageWithWeight(String broker, BrokerData brokerData,
+ ServiceConfiguration conf) {
+ final double historyPercentage = conf.getLoadBalancerHistoryResourcePercentage();
+ Double historyUsage = brokerAvgResourceUsageWithWeight.get(broker);
+ double resourceUsage = brokerData.getLocalData().getMaxResourceUsageWithWeight(
+ conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(),
+ conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ historyUsage = historyUsage == null
+ ? resourceUsage : historyUsage * historyPercentage + (1 - historyPercentage) * resourceUsage;
+ if (log.isDebugEnabled()) {
+ log.debug(
+ "Broker {} get max resource usage with weight: {}, history resource percentage: {}%, CPU weight: "
+ + "{}, MEMORY weight: {}, DIRECT MEMORY weight: {}, BANDWIDTH IN weight: {}, BANDWIDTH "
+ + "OUT weight: {} ",
+ broker, historyUsage, historyPercentage, conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ brokerAvgResourceUsageWithWeight.put(broker, historyUsage);
+ return historyUsage;
+ }
+
+ /**
+ * Find a suitable broker to assign the given bundle to.
+ *
+ * @param candidates The candidates for which the bundle may be assigned.
+ * @param bundleToAssign The data for the bundle to assign.
+ * @param loadData The load data from the leader broker.
+ * @param conf The service configuration.
+ * @return The name of the selected broker as it appears on ZooKeeper.
+ */
+ @Override
+ public Optional<String> selectBroker(Set<String> candidates, BundleData bundleToAssign, LoadData loadData,
+ ServiceConfiguration conf) {
+ bestBrokers.clear();
+ double minScore = Double.POSITIVE_INFINITY;
+ // Maintain of list of all the best scoring brokers and then randomly
+ // select one of them at the end.
+
+ for (String broker : candidates) {
+ final BrokerData brokerData = loadData.getBrokerData().get(broker);
+ final double score = getScore(broker, brokerData, conf);
+ if (score == Double.POSITIVE_INFINITY) {
+ final LocalBrokerData localData = brokerData.getLocalData();
+ log.warn(
+ "Broker {} is overloaded: CPU: {}%, MEMORY: {}%, DIRECT MEMORY: {}%, BANDWIDTH IN: {}%, "
+ + "BANDWIDTH OUT: {}%, CPU weight: {}, MEMORY weight: {}, DIRECT MEMORY weight: {}, "
+ + "BANDWIDTH IN weight: {}, BANDWIDTH OUT weight: {}",
+ broker, localData.getCpu().percentUsage(), localData.getMemory().percentUsage(),
+ localData.getDirectMemory().percentUsage(), localData.getBandwidthIn().percentUsage(),
+ localData.getBandwidthOut().percentUsage(), conf.getLoadBalancerCPUResourceWeight(),
+ conf.getLoadBalancerMemoryResourceWeight(), conf.getLoadBalancerDirectMemoryResourceWeight(),
+ conf.getLoadBalancerBandwithInResourceWeight(),
+ conf.getLoadBalancerBandwithOutResourceWeight());
+ }
+ if (score < minScore) {
+ bestBrokers.clear();
+ bestBrokers.add(broker);
+ minScore = score;
+ } else if (score == minScore) {
+ bestBrokers.add(broker);
+ }
+ }
+ if (bestBrokers.isEmpty()) {
+ // Assign randomly if all brokers are overloaded.
+ bestBrokers.addAll(candidates);
+ }
+
+ if (bestBrokers.isEmpty()) {
+ // If still, it means there are no available brokers at this point.
+ return Optional.empty();
+ }
+ return Optional.of(bestBrokers.get(ThreadLocalRandom.current().nextInt(bestBrokers.size())));
Review Comment:
Please add a debug log under `if (log.isDebugEnabled()) {` to log bestBrokers details(e.g. size) before the return.
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