[
https://issues.apache.org/jira/browse/GEODE-333?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14791223#comment-14791223
]
ASF subversion and git services commented on GEODE-333:
-------------------------------------------------------
Commit 2c99b9e6dbbae1f7fa169f43b3708328cb4d0ebf in incubator-geode's branch
refs/heads/develop from [~barry.oglesby]
[ https://git-wip-us.apache.org/repos/asf?p=incubator-geode.git;h=2c99b9e ]
GEODE-333: Indexes sometimes are no longer used after a rebalance
Incorporated changes from GemFire
> Indexes sometimes are no longer used after a rebalance
> ------------------------------------------------------
>
> Key: GEODE-333
> URL: https://issues.apache.org/jira/browse/GEODE-333
> Project: Geode
> Issue Type: Bug
> Components: querying
> Reporter: Barry Oglesby
> Assignee: Barry Oglesby
>
> My test defines the following index:
> {noformat}
> <index name="customer_displayName" from-clause="/customer"
> expression="displayName"/>
> {noformat}
> And the following query:
> {noformat}
> select * from /customer where displayName='some-display-name'
> {noformat}
> Query execution uses the index during execution before a rebalance takes
> place. In some cases (see below) the index is no longer used after a
> rebalance.
> When the issue occurs, the {{IndexManager getBestMatchIndex}} method returns
> no indexes for the {{index_iter1.displayName}} expression even though there
> is one.
> Here is some debugging that shows null being returned:
> {noformat}
> IndexManager getBestMatchIndex FUNCTIONAL index for index_iter1.displayName
> found null from [Index [ Name=customer_displayName Type =FUNCTIONAL
> IdxExp=displayName From=/customer Proj=*]imports : null]
> {noformat}
> This is due to this clause in the getBestMatchIndex method:
> {noformat}
> index = prIndex.getBucketIndex();
> if (index == null) {
> continue;
> }
> {noformat}
> The {{getBucketIndex}} method asks the first value in the {{bucketIndexes}}
> Map for its indexes. If the first value is empty, null is returned.
> In this case, the first value is empty because the index at that bucket
> ({{\_B__customer_47}}) was removed during the rebalance.
> Here is some debugging that shows it. The first value in the
> {{bucketIndexes}} Map is for {{\_B__customer_47}}. This bucket is removed
> during the rebalance, so its List of indexes initially contains an index,
> then it doesn't. This causes {{getBucketIndex}} to return null and causes
> {{getBestMatchIndex}} to short-circuit.
> {noformat}
> PartitionedIndex Bucket Indexes size=113; first
> entry=BucketRegion[path='/__PR/_B__customer_47;serial=149;primary=false;indexUpdater=null]=[Index
> [ Name=customer_displayName Type =FUNCTIONAL IdxExp=displayName
> From=/customer Proj=*]]
> PartitionedIndex removeFromBucketIndexes /__PR/_B__customer_47->Index [
> Name=customer_displayName Type =FUNCTIONAL IdxExp=displayName From=/customer
> Proj=*]
> PartitionedIndex Bucket Indexes size=113; first
> entry=BucketRegion[path='/__PR/_B__customer_47;serial=149;primary=false;indexUpdater=null]=[]
> {noformat}
> A potential fix is to remove any entries from the {{bucketIndexes}} Map that
> are empty in the {{removeFromBucketIndexes}} method like:
> {noformat}
> public void removeFromBucketIndexes(Region r, Index index)
> {
> synchronized(this.bucketIndexes) {
> List<Index> indexes = this.bucketIndexes.get(r);
> if(indexes != null) {
> indexes.remove(index);
> if (indexes.isEmpty()) {
> this.bucketIndexes.remove(r);
> }
> }
> }
> }
> {noformat}
> Here is some debugging that shows the first value in the {{bucketIndexes}}
> Map is initially for {{\_B\_\_customer_68}}. Then {{\_B\_\_customer_68}} is
> removed and {{\_B\_\_customer\_46}} takes over as first in the value in the
> {{bucketIndexes}} Map.
> {noformat}
> PartitionedIndex Bucket Indexes size=113; first
> entry=BucketRegion[path='/__PR/_B__customer_68;serial=209;primary=true;indexUpdater=null]=[Index
> [ Name=customer_displayName Type =FUNCTIONAL IdxExp=displayName
> From=/customer Proj=*]]
> PartitionedIndex removeFromBucketIndexes removing entry for
> /__PR/_B__customer_68
> PartitionedIndex Bucket Indexes size=95; first
> entry=BucketRegion[path='/__PR/_B__customer_46;serial=229;primary=false;indexUpdater=null]=[Index
> [ Name=customer_displayName Type =FUNCTIONAL IdxExp=displayName
> From=/customer Proj=*]]
> {noformat}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
