diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java index 9086ad3ea8c..6d0d1cacbb6 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java @@ -1858,6 +1858,8 @@ public class HMaster extends HRegionServer implements MasterServices { } } } + LOG.info("Balancer is going into sleep until next period in {}ms", getConfiguration() + .getInt(HConstants.HBASE_BALANCER_PERIOD, HConstants.DEFAULT_HBASE_BALANCER_PERIOD)); return successRegionPlans; } diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java index 96902b7e0b5..2e55b9b1839 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java @@ -74,6 +74,8 @@ import org.apache.hbase.thirdparty.com.google.common.collect.Sets; * */ @InterfaceAudience.Private +@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="IS2_INCONSISTENT_SYNC", + justification="Complaint is about isByTable not being synchronized; we don't modify often") public abstract class BaseLoadBalancer implements LoadBalancer { public static final String BALANCER_DECISION_BUFFER_ENABLED = diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.java index 20037c4ae63..da51175ccc6 100644 --- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.java +++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.java @@ -149,7 +149,8 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { private List candidateGenerators; private List costFunctions; // FindBugs: Wants this protected; IS2_INCONSISTENT_SYNC - + // To save currently configed sum of multiplier. Defaulted at 1 for cases that carry high cost + private float sumMultiplier = 1.0f; // to save and report costs to JMX private double curOverallCost = 0d; private double[] tempFunctionCosts; @@ -206,7 +207,6 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { } regionReplicaHostCostFunction = new RegionReplicaHostCostFunction(conf); regionReplicaRackCostFunction = new RegionReplicaRackCostFunction(conf); - costFunctions = new ArrayList<>(); addCostFunction(new RegionCountSkewCostFunction(conf)); addCostFunction(new PrimaryRegionCountSkewCostFunction(conf)); @@ -327,63 +327,65 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { protected boolean needsBalance(TableName tableName, Cluster cluster) { ClusterLoadState cs = new ClusterLoadState(cluster.clusterState); if (cs.getNumServers() < MIN_SERVER_BALANCE) { - if (LOG.isDebugEnabled()) { - LOG.debug("Not running balancer because only " + cs.getNumServers() - + " active regionserver(s)"); - } - if (this.isBalancerRejectionRecording) { - sendRejectionReasonToRingBuffer("The number of RegionServers " + - cs.getNumServers() + " < MIN_SERVER_BALANCE(" + MIN_SERVER_BALANCE + ")", null); - } + LOG.info("Not running balancer because only " + cs.getNumServers() + + " active regionserver(s)"); + sendRejectionReasonToRingBuffer("The number of RegionServers " + cs.getNumServers() + + " < MIN_SERVER_BALANCE(" + MIN_SERVER_BALANCE + ")", null); return false; } if (areSomeRegionReplicasColocated(cluster)) { + LOG.info("Running balancer because at least one server hosts replicas of the same region."); return true; } if (idleRegionServerExist(cluster)){ + LOG.info("Running balancer because cluster has idle server(s)."); return true; } + sumMultiplier = 0.0f; double total = 0.0; - float sumMultiplier = 0.0f; for (CostFunction c : costFunctions) { float multiplier = c.getMultiplier(); - if (multiplier <= 0) { - LOG.trace("{} not needed because multiplier is <= 0", c.getClass().getSimpleName()); - continue; - } + double cost = c.cost(); if (!c.isNeeded()) { LOG.trace("{} not needed", c.getClass().getSimpleName()); continue; } + total += cost * multiplier; sumMultiplier += multiplier; - total += c.cost() * multiplier; + } + if (sumMultiplier <= 0) { + LOG.error("At least one cost function needs a multiplier > 0. For example, set " + + "hbase.master.balancer.stochastic.regionCountCost to a positive value or default"); + return false; } - boolean balanced = total <= 0 || sumMultiplier <= 0 || - (sumMultiplier > 0 && (total / sumMultiplier) < minCostNeedBalance); - if(balanced && isBalancerRejectionRecording){ - String reason = ""; - if (total <= 0) { - reason = "(cost1*multiplier1)+(cost2*multiplier2)+...+(costn*multipliern) = " + total + " <= 0"; - } else if (sumMultiplier <= 0) { - reason = "sumMultiplier = " + sumMultiplier + " <= 0"; - } else if ((total / sumMultiplier) < minCostNeedBalance) { - reason = - "[(cost1*multiplier1)+(cost2*multiplier2)+...+(costn*multipliern)]/sumMultiplier = " + (total - / sumMultiplier) + " <= minCostNeedBalance(" + minCostNeedBalance + ")"; - } - sendRejectionReasonToRingBuffer(reason, costFunctions); - } - if (LOG.isDebugEnabled()) { - LOG.debug("{} {}; total cost={}, sum multiplier={}; cost/multiplier to need a balance is {}", - balanced ? "Skipping load balancing because balanced" : "We need to load balance", - isByTable ? String.format("table (%s)", tableName) : "cluster", - total, sumMultiplier, minCostNeedBalance); - if (LOG.isTraceEnabled()) { - LOG.trace("Balance decision detailed function costs={}", functionCost()); + boolean balanced = (total / sumMultiplier < minCostNeedBalance); + if (balanced) { + if (isBalancerRejectionRecording) { + String reason = ""; + if (total <= 0) { + reason = + "(cost1*multiplier1)+(cost2*multiplier2)+...+(costn*multipliern) = " + total + " <= 0"; + } else if (sumMultiplier <= 0) { + reason = "sumMultiplier = " + sumMultiplier + " <= 0"; + } else if ((total / sumMultiplier) < minCostNeedBalance) { + reason = + "[(cost1*multiplier1)+(cost2*multiplier2)+...+(costn*multipliern)]/sumMultiplier = " + ( + total / sumMultiplier) + " <= minCostNeedBalance(" + minCostNeedBalance + ")"; + } + sendRejectionReasonToRingBuffer(reason, costFunctions); } + LOG.info("{} - skipping load balancing because weighted average imbalance={} <= " + + "threshold({}). If you want more aggressive balancing, either lower " + + "hbase.master.balancer.stochastic.minCostNeedBalance from {} or increase the relative" + + " multiplier(s) of the specific cost function(s). functionCost={}", + isByTable ? "Table specific (" + tableName + ")" : "Cluster wide", total / sumMultiplier, + minCostNeedBalance, minCostNeedBalance, functionCost()); + } else { + LOG.info("{} - Calculating plan. may take up to {}ms to complete.", + isByTable ? "Table specific (" + tableName + ")" : "Cluster wide", maxRunningTime); } return !balanced; } @@ -419,8 +421,8 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { // Allow turning this feature off if the locality cost is not going to // be used in any computations. RegionLocationFinder finder = null; - if ((this.localityCost != null && this.localityCost.getMultiplier() > 0) - || (this.rackLocalityCost != null && this.rackLocalityCost.getMultiplier() > 0)) { + if ((this.localityCost != null && this.localityCost.getMultiplier() > 0) || ( + this.rackLocalityCost != null && this.rackLocalityCost.getMultiplier() > 0)) { finder = this.regionFinder; } @@ -446,21 +448,22 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { long computedMaxSteps; if (runMaxSteps) { computedMaxSteps = Math.max(this.maxSteps, - ((long)cluster.numRegions * (long)this.stepsPerRegion * (long)cluster.numServers)); + ((long) cluster.numRegions * (long) this.stepsPerRegion * (long) cluster.numServers)); } else { - long calculatedMaxSteps = (long)cluster.numRegions * (long)this.stepsPerRegion * - (long)cluster.numServers; + long calculatedMaxSteps = + (long) cluster.numRegions * (long) this.stepsPerRegion * (long) cluster.numServers; computedMaxSteps = Math.min(this.maxSteps, calculatedMaxSteps); if (calculatedMaxSteps > maxSteps) { - LOG.warn("calculatedMaxSteps:{} for loadbalancer's stochastic walk is larger than " - + "maxSteps:{}. Hence load balancing may not work well. Setting parameter " - + "\"hbase.master.balancer.stochastic.runMaxSteps\" to true can overcome this issue." - + "(This config change does not require service restart)", calculatedMaxSteps, - maxSteps); + LOG.warn("calculatedMaxSteps:{} for loadbalancer's stochastic walk is larger than " + + "maxSteps:{}. Hence load balancing may not work well. Setting parameter " + + "\"hbase.master.balancer.stochastic.runMaxSteps\" to true can overcome this issue." + + "(This config change does not require service restart)", calculatedMaxSteps, + maxSteps); } } - LOG.info("start StochasticLoadBalancer.balancer, initCost=" + currentCost + ", functionCost=" - + functionCost() + " computedMaxSteps: " + computedMaxSteps); + LOG.info("Start StochasticLoadBalancer.balancer, initial weighted average imbalance={}," + + " functionCost={} computedMaxSteps={}", + currentCost / sumMultiplier, functionCost(), computedMaxSteps); final String initFunctionTotalCosts = totalCostsPerFunc(); // Perform a stochastic walk to see if we can get a good fit. @@ -493,8 +496,7 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { updateCostsWithAction(cluster, undoAction); } - if (EnvironmentEdgeManager.currentTime() - startTime > - maxRunningTime) { + if (EnvironmentEdgeManager.currentTime() - startTime > maxRunningTime) { break; } } @@ -506,17 +508,18 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { updateStochasticCosts(tableName, curOverallCost, curFunctionCosts); if (initCost > currentCost) { plans = createRegionPlans(cluster); - LOG.info("Finished computing new load balance plan. Computation took {}" + - " to try {} different iterations. Found a solution that moves " + - "{} regions; Going from a computed cost of {}" + - " to a new cost of {}", java.time.Duration.ofMillis(endTime - startTime), - step, plans.size(), initCost, currentCost); + LOG.info("Finished computing new moving plan. Computation took {} ms" + + " to try {} different iterations. Found a solution that moves " + + "{} regions; Going from a computed imbalance of {}" + " to a new imbalance of {}. ", + endTime - startTime, step, plans.size(), initCost / sumMultiplier, + currentCost / sumMultiplier); + sendRegionPlansToRingBuffer(plans, currentCost, initCost, initFunctionTotalCosts, step); return plans; } - LOG.info("Could not find a better load balance plan. Tried {} different configurations in " + - "{}, and did not find anything with a computed cost less than {}", step, - java.time.Duration.ofMillis(endTime - startTime), initCost); + LOG.info("Could not find a better moving plan. Tried {} different configurations in " + + "{} ms, and did not find anything with an imbalance score less than {}", step, + endTime - startTime, initCost / sumMultiplier); return null; } @@ -527,8 +530,7 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { .setReason(reason); if (costFunctions != null) { for (CostFunction c : costFunctions) { - float multiplier = c.getMultiplier(); - if (multiplier <= 0 || !c.isNeeded()) { + if (!c.isNeeded()) { continue; } builder.addCostFuncInfo(c.getClass().getName(), c.cost(), c.getMultiplier()); @@ -587,7 +589,8 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { } private void addCostFunction(CostFunction costFunction) { - if (costFunction.getMultiplier() > 0) { + float multiplier = costFunction.getMultiplier(); + if (multiplier > 0) { costFunctions.add(costFunction); } } @@ -598,9 +601,13 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { builder.append(c.getClass().getSimpleName()); builder.append(" : ("); if (c.isNeeded()) { - builder.append(c.getMultiplier()); + builder.append("multiplier=" + c.getMultiplier()); builder.append(", "); - builder.append(c.cost()); + double cost = c.cost(); + builder.append("imbalance=" + cost); + if (cost < minCostNeedBalance) { + builder.append(", balanced"); + } } else { builder.append("not needed"); } @@ -612,7 +619,7 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { private String totalCostsPerFunc() { StringBuilder builder = new StringBuilder(); for (CostFunction c : costFunctions) { - if (c.getMultiplier() <= 0 || !c.isNeeded()) { + if (!c.isNeeded()) { continue; } double cost = c.getMultiplier() * c.cost(); @@ -696,7 +703,7 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { allowedOnPath = ".*(/src/test/.*|StochasticLoadBalancer).java") void updateCostsWithAction(Cluster cluster, Action action) { for (CostFunction c : costFunctions) { - if (c.getMultiplier() > 0 && c.isNeeded()) { + if (c.isNeeded()) { c.postAction(action); } } @@ -735,7 +742,7 @@ public class StochasticLoadBalancer extends BaseLoadBalancer { CostFunction c = costFunctions.get(i); this.tempFunctionCosts[i] = 0.0; - if (c.getMultiplier() <= 0 || !c.isNeeded()) { + if (!c.isNeeded()) { continue; }