Qifan Chen has uploaded a new patch set (#14). ( http://gerrit.cloudera.org:8080/17872 )
Change subject: IMPALA-10811 RPC to submit query getting stuck for AWS NLB forever ...................................................................... IMPALA-10811 RPC to submit query getting stuck for AWS NLB forever This patch addresses Impala client hang due to AWS network load balancer timeout which is fixed at 350s. When some long DDL operations are going on and the timeout happens, AWS silently drops the connection and the Impala client enters the hang state. The fix maintains the TCLIService protocol between the client and Impala server and applies to the following Impala clients which issue thrift RPC ExecuteStatement() followed by repeated call to GetOperationStatus() (HS2, Impyla and HUE) or a variant of it (Beeswax) to Impala backend. 1. HS2 2. Beeswax 3. Impyla 4. HUE In the fix, the backend method ImpalaServer::ExecuteStatementCommon() starts a new thread for ImpalaServer::ExecuteStatementCommonInternal() which can reach two states: COMPILED and DONE. The COMPILED is when the front end has successfully compiled the query and the DONE is for the execution of the query plan to reach the end successfully or to encounter any errors. The main thread, which start the new thread, waits for the COMPILED state before advancing to another short wait period for the DONE state. If the DONE state is not reached, the control is returned back to the client and the client will issue GetOperationStatus() repeatedly to check if the execution has reached the DONE state. When Impala server detects the FINISHED execution state or there is error in servicing GetOperationStatus(), the new thread is joined and released. The communications between the new and the host thread are per session. Thus for a long DDL query, its execution part is done in the new thread and the Impala client keeps checking its status via GetOperationStatus() without waiting more than 350s. In addition, a cild query, which is submitted from the Impala server as an Impala client for compute stats stmt, runs synchronously in the same child query thread. Testing: TBD Change-Id: Ib57e86926a233ef13d27a9ec8d9c36d33a88a44e --- M be/src/service/child-query.cc M be/src/service/client-request-state.cc M be/src/service/impala-beeswax-server.cc M be/src/service/impala-hs2-server.cc M be/src/service/impala-server.cc M be/src/service/impala-server.h M be/src/util/thread.h 7 files changed, 318 insertions(+), 28 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/72/17872/14 -- To view, visit http://gerrit.cloudera.org:8080/17872 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: Ib57e86926a233ef13d27a9ec8d9c36d33a88a44e Gerrit-Change-Number: 17872 Gerrit-PatchSet: 14 Gerrit-Owner: Qifan Chen <qc...@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Joe McDonnell <joemcdonn...@cloudera.com> Gerrit-Reviewer: Qifan Chen <qc...@cloudera.com>
