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Posted to commits@hbase.apache.org by bu...@apache.org on 2020/04/08 19:03:45 UTC
[hbase] branch master 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 master
in repository https://gitbox.apache.org/repos/asf/hbase.git
The following commit(s) were added to refs/heads/master by this push:
new 2d78a28 HBASE-24138 log more details about balancer decisions for StochasticLoadBalancer (#1455)
2d78a28 is described below
commit 2d78a286b682b34e8a718c521e265d58536f1e5e
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>
---
.../hbase/master/balancer/ServerAndLoad.java | 5 +++
.../master/balancer/StochasticLoadBalancer.java | 36 ++++++++++++++--------
.../hbase/master/balancer/BalancerTestBase.java | 13 +++++---
3 files changed, 37 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 3675bd3..0698d12 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 c9fe090..e63a6b9 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
@@ -331,28 +331,29 @@ public class StochasticLoadBalancer extends BaseLoadBalancer {
for (CostFunction c : costFunctions) {
float multiplier = c.getMultiplier();
if (multiplier <= 0) {
+ LOG.trace("{} not needed because multiplier is <= 0", c.getClass().getSimpleName());
continue;
}
if (!c.isNeeded()) {
- LOG.debug("{} not needed", c.getClass().getSimpleName());
+ LOG.trace("{} not needed", c.getClass().getSimpleName());
continue;
}
sumMultiplier += multiplier;
total += c.cost() * multiplier;
}
- if (total <= 0 || sumMultiplier <= 0
- || (sumMultiplier > 0 && (total / sumMultiplier) < minCostNeedBalance)) {
+ boolean balanced = total <= 0 || sumMultiplier <= 0 ||
+ (sumMultiplier > 0 && (total / sumMultiplier) < minCostNeedBalance);
+ 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()) {
- final String loadBalanceTarget =
- isByTable ? String.format("table (%s)", tableName) : "cluster";
- LOG.trace("Skipping load balancing because the {} is balanced. Total cost: {}, "
- + "Sum multiplier: {}, Minimum cost needed for balance: {}", loadBalanceTarget, total,
- sumMultiplier, minCostNeedBalance);
+ LOG.trace("Balance decision detailed function costs={}", functionCost());
}
- return false;
}
- return true;
+ return !balanced;
}
@VisibleForTesting
@@ -1190,15 +1191,26 @@ public class StochasticLoadBalancer extends BaseLoadBalancer {
}
@Override
+ void init(Cluster cluster) {
+ super.init(cluster);
+ LOG.debug("{} sees a total of {} servers and {} regions.", getClass().getSimpleName(),
+ cluster.numServers, cluster.numRegions);
+ if (LOG.isTraceEnabled()) {
+ for (int i =0; i < cluster.numServers; i++) {
+ LOG.trace("{} sees server '{}' has {} regions", getClass().getSimpleName(),
+ cluster.servers[i], cluster.regionsPerServer[i].length);
+ }
+ }
+ }
+
+ @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 6231059..685088f 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
@@ -201,9 +201,11 @@ 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);
}
}
@@ -561,7 +563,7 @@ public class BalancerTestBase {
Map<TableName, Map<ServerName, List<RegionInfo>>> LoadOfAllTable =
(Map) mockClusterServersWithTables(serverMap);
List<RegionPlan> plans = loadBalancer.balanceCluster(LoadOfAllTable);
- assertNotNull(plans);
+ assertNotNull("Initial cluster balance should produce plans.", plans);
// Check to see that this actually got to a stable place.
if (assertFullyBalanced || assertFullyBalancedForReplicas) {
@@ -575,7 +577,8 @@ public class BalancerTestBase {
assertClusterAsBalanced(balancedCluster);
LoadOfAllTable = (Map) mockClusterServersWithTables(serverMap);
List<RegionPlan> secondPlans = loadBalancer.balanceCluster(LoadOfAllTable);
- assertNull(secondPlans);
+ assertNull("Given a requirement to be fully balanced, second attempt at plans should " +
+ "produce none.", secondPlans);
}
if (assertFullyBalancedForReplicas) {