[
https://issues.apache.org/jira/browse/HBASE-26297?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Clara Xiong updated HBASE-26297:
--------------------------------
Description:
{code:java}
protected synchronized boolean areSomeRegionReplicasColocated(Cluster c) {
regionReplicaHostCostFunction.init(c);
if (regionReplicaHostCostFunction.cost() > 0) {
return true;
}
regionReplicaRackCostFunction.init(c);
if (regionReplicaRackCostFunction.cost() > 0) {
return true;
}
{code}
The values are in double data type. Balancer could get stuck in constant runs
and unnecessary moves.
{code:java}
2021-09-24 12:02:41,943 INFO
org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Running
balancer because at least one server hosts replicas of the same region.
2021-09-24 12:01:42,878 INFO
org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Finished
computing new moving plan. Computation took 2400001 ms to try 3048341 different
iterations. Found a solution that moves 81 regions; Going from a computed
imbalance of 1.7429830473781883E-4 to a new imbalance of 1.6169961756947032E-4.
{code}
we should use COST_EPSILON instead of 0 for double comparison.
was:
{code:java}
protected synchronized boolean areSomeRegionReplicasColocated(Cluster c) {
regionReplicaHostCostFunction.init(c);
if (regionReplicaHostCostFunction.cost() > 0) {
return true;
}
regionReplicaRackCostFunction.init(c);
if (regionReplicaRackCostFunction.cost() > 0) {
return true;
}
{code}
The values are in double data type. we often run into unnecessary runs.
{code:java}
2021-09-24 12:02:41,943 INFO
org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Running
balancer because at least one server hosts replicas of the same region.
2021-09-24 12:01:42,878 INFO
org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Finished
computing new moving plan. Computation took 2400001 ms to try 3048341 different
iterations. Found a solution that moves 81 regions; Going from a computed
imbalance of 1.7429830473781883E-4 to a new imbalance of 1.6169961756947032E-4.
{code}
we should use COST_EPSILON instead of 0 for double comparison.
> Balancer run is improperly triggered by accuracy error of double comparison
> ---------------------------------------------------------------------------
>
> Key: HBASE-26297
> URL: https://issues.apache.org/jira/browse/HBASE-26297
> Project: HBase
> Issue Type: Bug
> Components: Balancer
> Environment: {code:java}
> {code}
> Reporter: Clara Xiong
> Assignee: Clara Xiong
> Priority: Major
>
> {code:java}
> protected synchronized boolean areSomeRegionReplicasColocated(Cluster c) {
> regionReplicaHostCostFunction.init(c);
> if (regionReplicaHostCostFunction.cost() > 0) {
> return true;
> }
> regionReplicaRackCostFunction.init(c);
> if (regionReplicaRackCostFunction.cost() > 0) {
> return true;
> }
> {code}
> The values are in double data type. Balancer could get stuck in constant runs
> and unnecessary moves.
> {code:java}
> 2021-09-24 12:02:41,943 INFO
> org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Running
> balancer because at least one server hosts replicas of the same region.
> 2021-09-24 12:01:42,878 INFO
> org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer: Finished
> computing new moving plan. Computation took 2400001 ms to try 3048341
> different iterations. Found a solution that moves 81 regions; Going from a
> computed imbalance of 1.7429830473781883E-4 to a new imbalance of
> 1.6169961756947032E-4.
> {code}
> we should use COST_EPSILON instead of 0 for double comparison.
>
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
