[
https://issues.apache.org/jira/browse/HBASE-20917?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16586485#comment-16586485
]
Ted Yu commented on HBASE-20917:
--------------------------------
bq. is there anything to stop requestsMap being set to null after the check but
before the use?
As far as I can tell, requestsMap is private. I only found one assignment to
this field in the start() method. Meaning after the field is assigned, it
wouldn't be set to null.
As to why the null check is needed, see the following from description:
bq. requestsMap is only initialized for the meta region.
bq. It doesn't look like its committed yet.
Let me know if I should merge the fix to 2.0 branch or you're going to merge
the fix yourself.
thanks
> MetaTableMetrics#stop references uninitialized requestsMap for non-meta region
> ------------------------------------------------------------------------------
>
> Key: HBASE-20917
> URL: https://issues.apache.org/jira/browse/HBASE-20917
> Project: HBase
> Issue Type: Bug
> Reporter: Ted Yu
> Assignee: Ted Yu
> Priority: Major
> Fix For: 3.0.0, 1.5.0, 1.4.6, 2.0.2, 2.2.0, 2.1.1
>
> Attachments: 20917.addendum, 20917.v1.txt, 20917.v2.txt
>
>
> I noticed the following in test output:
> {code}
> 2018-07-21 15:54:43,181 ERROR [RS_CLOSE_REGION-regionserver/172.17.5.4:0-1]
> executor.EventHandler(186): Caught throwable while processing event
> M_RS_CLOSE_REGION
> java.lang.NullPointerException
> at
> org.apache.hadoop.hbase.coprocessor.MetaTableMetrics.stop(MetaTableMetrics.java:329)
> at
> org.apache.hadoop.hbase.coprocessor.BaseEnvironment.shutdown(BaseEnvironment.java:91)
> at
> org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost$RegionEnvironment.shutdown(RegionCoprocessorHost.java:165)
> at
> org.apache.hadoop.hbase.coprocessor.CoprocessorHost.shutdown(CoprocessorHost.java:290)
> at
> org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost$4.postEnvCall(RegionCoprocessorHost.java:559)
> at
> org.apache.hadoop.hbase.coprocessor.CoprocessorHost.execOperation(CoprocessorHost.java:622)
> at
> org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost.postClose(RegionCoprocessorHost.java:551)
> at org.apache.hadoop.hbase.regionserver.HRegion.doClose(HRegion.java:1678)
> at org.apache.hadoop.hbase.regionserver.HRegion.close(HRegion.java:1484)
> at
> org.apache.hadoop.hbase.regionserver.handler.CloseRegionHandler.process(CloseRegionHandler.java:104)
> at org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:104)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
> {code}
> {{requestsMap}} is only initialized for the meta region.
> However, check for meta region is absent in the stop method:
> {code}
> public void stop(CoprocessorEnvironment e) throws IOException {
> // since meta region can move around, clear stale metrics when stop.
> for (String meterName : requestsMap.keySet()) {
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
