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https://issues.apache.org/jira/browse/HBASE-13480?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14681987#comment-14681987
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Josh Elser commented on HBASE-13480:
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Hi [~jingcheng...@intel.com]. I'd have to look at the code again, but your
suggestion does sound reasonable. I'm not sure if there are other locations
lurking around in the code which would have this problem. I'm wondering if
Enis' suggestion of ConnectionAdapter extending ConnectionImplementation
instead is the less-error-prone approach. If we can make sure we pass around
the ability to shortcircuit, that should reduce the change to make sure we use
the SCC when we can.
> 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: Josh Elser
> Fix For: 2.0.0, 1.3.0, 1.2.1, 1.0.3, 1.1.3
>
>
> 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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