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Posted to commits@hbase.apache.org by bu...@apache.org on 2020/04/09 05:31:52 UTC
[hbase] branch branch-1 updated: HBASE-24138 log more details about
balancer decisions for StochasticLoadBalancer (#1455)
This is an automated email from the ASF dual-hosted git repository.
busbey pushed a commit to branch branch-1
in repository https://gitbox.apache.org/repos/asf/hbase.git
The following commit(s) were added to refs/heads/branch-1 by this push:
new 4b94f2e HBASE-24138 log more details about balancer decisions for StochasticLoadBalancer (#1455)
4b94f2e is described below
commit 4b94f2ed417e1776dd736d6903e9ba66dc1b08a0
Author: Sean Busbey <bu...@apache.org>
AuthorDate: Wed Apr 8 14:03:33 2020 -0500
HBASE-24138 log more details about balancer decisions for StochasticLoadBalancer (#1455)
- at DEBUG log messages about RegionCountSkewCostFunction region/server totals
- at DEBUG log messages about the decision to balance or not with total costs
- at TRACE log messages about region count on each server RegionCountSkewCostFunction sees
- at TRACE log message with the individual cost functions used in the decision to balance or not
Signed-off-by: Viraj Jasani <vj...@apache.org>
(cherry picked from commit 2d78a286b682b34e8a718c521e265d58536f1e5e)
---
.../hbase/master/balancer/ServerAndLoad.java | 5 +++
.../master/balancer/StochasticLoadBalancer.java | 43 ++++++++++++++++------
.../hbase/master/balancer/BalancerTestBase.java | 13 ++++---
3 files changed, 44 insertions(+), 17 deletions(-)
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/ServerAndLoad.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/ServerAndLoad.java
index cceaf87..25086d6 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/ServerAndLoad.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/ServerAndLoad.java
@@ -65,4 +65,9 @@ class ServerAndLoad implements Comparable<ServerAndLoad>, Serializable {
}
return false;
}
+
+ @Override
+ public String toString() {
+ return "server=" + sn + " , load=" + load;
+ }
}
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 60c8b67..f3c756c 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
@@ -334,26 +334,34 @@ public class StochasticLoadBalancer extends BaseLoadBalancer {
for (CostFunction c : costFunctions) {
float multiplier = c.getMultiplier();
if (multiplier <= 0) {
+ if (LOG.isTraceEnabled()) {
+ LOG.trace(c.getClass().getSimpleName() + " not needed because multiplier is <= 0");
+ }
continue;
}
if (!c.isNeeded()) {
- LOG.debug(c.getClass().getName() + " indicated that its cost should not be considered");
+ if (LOG.isTraceEnabled()) {
+ LOG.trace(c.getClass().getSimpleName() + " not needed");
+ }
continue;
}
sumMultiplier += multiplier;
total += c.cost() * multiplier;
}
- if (total <= 0 || sumMultiplier <= 0
- || (sumMultiplier > 0 && (total / sumMultiplier) < minCostNeedBalance)) {
- final String loadBalanceTarget =
- isByTable ? String.format("table (%s)", tableName) : "cluster";
- LOG.info(String.format("Skipping load balancing because the %s is balanced. Total cost: %s, "
- + "Sum multiplier: %s, Minimum cost needed for balance: %s", loadBalanceTarget, total,
- sumMultiplier, minCostNeedBalance));
- return false;
+ boolean balanced = total <= 0 || sumMultiplier <= 0 ||
+ (sumMultiplier > 0 && (total / sumMultiplier) < minCostNeedBalance);
+ if (LOG.isDebugEnabled()) {
+ LOG.debug(
+ (balanced ? "Skipping load balancing because balanced" : "We need to load balance") +
+ " " + (isByTable ? String.format("table (%s)", tableName) : "cluster") +
+ "; total cost=" + total + ", sum multiplier=" + sumMultiplier + "; cost/multiplier to " +
+ "need a balance is " + minCostNeedBalance);
+ if (LOG.isTraceEnabled()) {
+ LOG.trace("Balance decision detailed function costs=" + functionCost());
+ }
}
- return true;
+ return !balanced;
}
@Override
@@ -1208,15 +1216,26 @@ public class StochasticLoadBalancer extends BaseLoadBalancer {
}
@Override
+ void init(Cluster cluster) {
+ super.init(cluster);
+ LOG.debug(getClass().getSimpleName() + " sees a total of " + cluster.numServers +
+ " servers and " + cluster.numRegions + " regions.");
+ if (LOG.isTraceEnabled()) {
+ for (int i =0; i < cluster.numServers; i++) {
+ LOG.trace(getClass().getSimpleName() + " sees server '" + cluster.servers[i] +
+ "' has " + cluster.regionsPerServer[i].length + " regions");
+ }
+ }
+ }
+
+ @Override
protected double cost() {
if (stats == null || stats.length != cluster.numServers) {
stats = new double[cluster.numServers];
}
-
for (int i =0; i < cluster.numServers; i++) {
stats[i] = cluster.regionsPerServer[i].length;
}
-
return costFromArray(stats);
}
}
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/BalancerTestBase.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/BalancerTestBase.java
index adeebd2..bc0ae82 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/BalancerTestBase.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/BalancerTestBase.java
@@ -202,9 +202,11 @@ public class BalancerTestBase {
int max = numRegions % numServers == 0 ? min : min + 1;
for (ServerAndLoad server : servers) {
- assertTrue(server.getLoad() >= 0);
- assertTrue(server.getLoad() <= max);
- assertTrue(server.getLoad() >= min);
+ assertTrue("All servers should have a positive load. " + server, server.getLoad() >= 0);
+ assertTrue("All servers should have load no more than " + max + ". " + server,
+ server.getLoad() <= max);
+ assertTrue("All servers should have load no less than " + min + ". " + server,
+ server.getLoad() >= min);
}
}
@@ -434,7 +436,7 @@ public class BalancerTestBase {
loadBalancer.setRackManager(rackManager);
// Run the balancer.
List<RegionPlan> plans = loadBalancer.balanceCluster(serverMap);
- assertNotNull(plans);
+ assertNotNull("Initial cluster balance should produce plans.", plans);
// Check to see that this actually got to a stable place.
if (assertFullyBalanced || assertFullyBalancedForReplicas) {
@@ -447,7 +449,8 @@ public class BalancerTestBase {
if (assertFullyBalanced) {
assertClusterAsBalanced(balancedCluster);
List<RegionPlan> secondPlans = loadBalancer.balanceCluster(serverMap);
- assertNull(secondPlans);
+ assertNull("Given a requirement to be fully balanced, second attempt at plans should " +
+ "produce none.", secondPlans);
}
if (assertFullyBalancedForReplicas) {