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https://issues.apache.org/jira/browse/HBASE-13480?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14702466#comment-14702466
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Jesse Yates commented on HBASE-13480:
-------------------------------------
I'm not very surprised this has been causing issues in the master - it was
originally intended just a regionserver local thing only (and as such, any
calls to the master were expected to go via an RPC) and wanted a minimum impact
change. Anyways, this seems to be a more general approach, which is nice :).
I'm not concerned about changing the signature [~lhofhansl] - the class is
already marked InterfaceAudience.Private, so any changes are to our discretion,
no? I would like to see tests around the changes to ensure we don't get into
this situation again though. Otherwise, LGTM
> ShortCircuitConnection doesn't short-circuit all calls as expected
> ------------------------------------------------------------------
>
> Key: HBASE-13480
> URL: https://issues.apache.org/jira/browse/HBASE-13480
> Project: HBase
> Issue Type: Bug
> Components: Client
> Affects Versions: 1.0.0, 2.0.0, 1.1.0
> Reporter: Josh Elser
> Assignee: Jingcheng Du
> Fix For: 2.0.0, 1.3.0, 1.2.1, 1.0.3, 1.1.3
>
> Attachments: HBASE-13480.patch
>
>
> Noticed the following situation in debugging unexpected unit tests failures
> in HBASE-13351.
> {{ConnectionUtils#createShortCircuitHConnection(Connection, ServerName,
> AdminService.BlockingInterface, ClientService.BlockingInterface)}} is
> intended to avoid the extra RPC by calling the server's instantiation of the
> protobuf rpc stub directly for the AdminService and ClientService.
> The problem is that this is insufficient to actually avoid extra "remote"
> RPCs as all other calls to the Connection are routed to a "real" Connection
> instance. As such, any object created by the "real" Connection (such as an
> HTable) will use the real Connection, not the SSC.
> The end result is that
> {{MasterRpcService#reportRegionStateTransition(RpcController,
> ReportRegionStateTransitionRequest)}} will make additional "remote" RPCs over
> what it thinks is an SSC through a {{Get}} on {{HTable}} which was
> constructed using the SSC, but the {{Get}} itself will use the underlying
> real Connection instead of the SSC. With insufficiently sized thread pools,
> this has been observed to result in RPC deadlock in the HMaster where an RPC
> attempts to make another RPC but there are no more threads available to
> service the second RPC so the first RPC blocks indefinitely.
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