[jira] [Resolved] (HBASE-11295) Long running scan produces OutOfOrderScannerNextException

["Anoop Sam John (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-11295?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Anoop Sam John resolved HBASE-11295.
------------------------------------

    Resolution: Not a Problem

> Long running scan produces OutOfOrderScannerNextException
> ---------------------------------------------------------
>
>                 Key: HBASE-11295
>                 URL: https://issues.apache.org/jira/browse/HBASE-11295
>             Project: HBase
>          Issue Type: Bug
>          Components: regionserver
>    Affects Versions: 0.96.0
>            Reporter: Jeff Cunningham
>         Attachments: OutOfOrderScannerNextException.tar.gz
>
>
> Attached Files:
> HRegionServer.java - instramented from 0.96.1.1-cdh5.0.0
> HBaseLeaseTimeoutIT.java - reproducing JUnit 4 test
> WaitFilter.java - Scan filter (extends FilterBase) that overrides filterRowKey() to sleep during invocation
> SpliceFilter.proto - Protobuf defintiion for WaitFilter.java
> OutOfOrderScann_InstramentedServer.log - instramented server log
> Steps.txt - this note
> Set up:
> In HBaseLeaseTimeoutIT, create a scan, set the given filter (which sleeps in overridden filterRowKey() method) and set it on the scan, and scan the table.
> This is done in test client_0x0_server_150000x10().
> Here's what I'm seeing (see also attached log):
> A new request comes into server (ID 1940798815214593802 - RpcServer.handler=96) and a RegionScanner is created for it, cached by ID, immediately looked up again and cached RegionScannerHolder's nextCallSeq incremeted (now at 1).
> The RegionScan thread goes to sleep in WaitFilter#filterRowKey().
> A short (variable) period later, another request comes into the server (ID 8946109289649235722 - RpcServer.handler=98) and the same series of events happen to this request.
> At this point both RegionScanner threads are sleeping in WaitFilter.filterRowKey(). After another period, the client retries another scan request which thinks its next_call_seq is 0.  However, HRegionServer's cached RegionScannerHolder thinks the matching RegionScanner's nextCallSeq should be 1.



--
This message was sent by Atlassian JIRA
(v6.2#6252)