Andrew Wong has submitted this change and it was merged. ( http://gerrit.cloudera.org:8080/13384 )
Change subject: hms: fix flakiness of master-stress-test from managed tables ...................................................................... hms: fix flakiness of master-stress-test from managed tables The switch to managed tables opened the door for the race described in HIVE-21759, described with more Kudu-specific details below: 1. Master A* sends a create table request for T. 2. The HMS creates a directory for that table and an entry in the HMS catalog. 3. Before A* can write this to the Kudu catalog, master B* becomes leader. A's write fails, and A sends a drop request to the HMS to roll back the created metadata for T. 4. The HMS receives A's drop request, and the HMS entry is dropped. Note: In the process of dropping a table from the HMS, the last thing the operation will do is drop any underlying data in the HMS (the directory, in this case). 5. The create request for T is retried by B*. Because the HMS entry for T is already dropped in the HMS, the request will be processed. 6. The HMS finally drops the underlying directory for T created by A. 7. Along the path of creating the table, the request from B* hits a "Not found" exception, expecting for the directory for T to exist. 8. The create table request is failed, since the HMS transaction to create the table is failed. The end result is that the table doesn't exist in Kudu or in the HMS following this sequence of events. This patch addresses this by catching such errors with the HMS enabled and checking that an underlying Kudu table and HMS entry is not created if so. Without this patch, master-stress-test failed 24/300 times with 7 stress threads. With it, it failed 9/300 times (mostly due to KUDU-2779). Change-Id: I1233e5b133035d36f98ce08265c0273570caa454 Reviewed-on: http://gerrit.cloudera.org:8080/13384 Reviewed-by: Hao Hao <hao....@cloudera.com> Tested-by: Andrew Wong <aw...@cloudera.com> --- M src/kudu/integration-tests/master-stress-test.cc 1 file changed, 38 insertions(+), 0 deletions(-) Approvals: Hao Hao: Looks good to me, approved Andrew Wong: Verified -- To view, visit http://gerrit.cloudera.org:8080/13384 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: merged Gerrit-Change-Id: I1233e5b133035d36f98ce08265c0273570caa454 Gerrit-Change-Number: 13384 Gerrit-PatchSet: 4 Gerrit-Owner: Andrew Wong <aw...@cloudera.com> Gerrit-Reviewer: Adar Dembo <a...@cloudera.com> Gerrit-Reviewer: Alexey Serbin <aser...@cloudera.com> Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com> Gerrit-Reviewer: Grant Henke <granthe...@apache.org> Gerrit-Reviewer: Hao Hao <hao....@cloudera.com> Gerrit-Reviewer: Kudu Jenkins (120)
