Michael Ho has posted comments on this change. ( http://gerrit.cloudera.org:8080/13306 )
Change subject: IMPALA-1653: Don't close hiveserver2 session when connection is closed ...................................................................... Patch Set 3: (1 comment) http://gerrit.cloudera.org:8080/#/c/13306/3//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/13306/3//COMMIT_MSG@30 PS3, Line 30: We may want to consider changing : some of this behavior. > We probably should consider removing states of expired sessions or Impala m To be fair, Impala is already vulnerable to similar kind of DoS attack today. A client can establish many connections to an Impala server, consuming all the FE service threads while leaving the sessions idle. All other clients will be blocked by this misbehaving client. See IMPALA-7802. Before this change, we could have as many sessions as number of FE service threads. After this change, the session will be kept alive even after the connection is closed so we could in theory have way more sessions than number of FE service threads. It seems there is a more pressing need for idle session timeout after this patch as it seems easier to create the situation of issuing a query without fetching all the results, holding up resources in the cluster but I could be missing something. Previously, the client disconnection will automatically close the session and unregistering all in-flight queries, freeing up the resources. -- To view, visit http://gerrit.cloudera.org:8080/13306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ia4555cd9b73db5b4dde92cd4fac4f9bfa3664d78 Gerrit-Change-Number: 13306 Gerrit-PatchSet: 3 Gerrit-Owner: Thomas Marshall <[email protected]> Gerrit-Reviewer: Andrew Sherman <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Thomas Marshall <[email protected]> Gerrit-Comment-Date: Wed, 15 May 2019 07:22:32 +0000 Gerrit-HasComments: Yes
