hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew Purtell (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-5097) RegionObserver implementation whose preScannerOpen and postScannerOpen Impl return null can stall the system initialization through NPE
Date Wed, 28 Dec 2011 19:36:30 GMT

    [ https://issues.apache.org/jira/browse/HBASE-5097?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13176786#comment-13176786
] 

Andrew Purtell commented on HBASE-5097:
---------------------------------------

bq. We should save the non-null s before calling postScannerOpen(). If postScannerOpen() returns
null, we can use the saved scanner.

... and emit a warning. Sounds good.
                
> RegionObserver implementation whose preScannerOpen and postScannerOpen Impl return null
can stall the system initialization through NPE
> ---------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: HBASE-5097
>                 URL: https://issues.apache.org/jira/browse/HBASE-5097
>             Project: HBase
>          Issue Type: Bug
>          Components: coprocessors
>            Reporter: ramkrishna.s.vasudevan
>
> In HRegionServer.java openScanner()
> {code}
>       r.prepareScanner(scan);
>       RegionScanner s = null;
>       if (r.getCoprocessorHost() != null) {
>         s = r.getCoprocessorHost().preScannerOpen(scan);
>       }
>       if (s == null) {
>         s = r.getScanner(scan);
>       }
>       if (r.getCoprocessorHost() != null) {
>         s = r.getCoprocessorHost().postScannerOpen(scan, s);
>       }
> {code}
> If we dont have implemention for postScannerOpen the RegionScanner is null and so throwing
nullpointer 
> {code}
> java.lang.NullPointerException
> 	at java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:881)
> 	at org.apache.hadoop.hbase.regionserver.HRegionServer.addScanner(HRegionServer.java:2282)
> 	at org.apache.hadoop.hbase.regionserver.HRegionServer.openScanner(HRegionServer.java:2272)
> 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> 	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> 	at java.lang.reflect.Method.invoke(Method.java:597)
> 	at org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(WritableRpcEngine.java:364)
> 	at org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1326)
> {code}
> Making this defect as blocker.. Pls feel free to change the priority if am wrong.  Also
correct me if my way of trying out coprocessors without implementing postScannerOpen is wrong.
 Am just a learner.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message