[ https://issues.apache.org/jira/browse/CASSANDRA-15666?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
ZhaoYang updated CASSANDRA-15666: --------------------------------- Test and Documentation Plan: Added interceptor to verify stream messages and state transition. CI: [https://circleci.com/workflow-run/8f0447ac-d995-42ac-a631-6c49bc32b76c] dtest failure "repair_test.py" is fixed in [https://github.com/apache/cassandra-dtest/pull/63] was: Added interceptor to verify stream messages and state transition. CI: [https://circleci.com/workflow-run/d7e2fdab-7c5e-4653-a6c2-07515c0eb205] dtest failure "repair_test.py" is fixed in [https://github.com/apache/cassandra-dtest/pull/63] > Race condition when completing stream sessions > ---------------------------------------------- > > Key: CASSANDRA-15666 > URL: https://issues.apache.org/jira/browse/CASSANDRA-15666 > Project: Cassandra > Issue Type: Bug > Components: Legacy/Streaming and Messaging > Reporter: Sergio Bossa > Assignee: ZhaoYang > Priority: Normal > Labels: pull-request-available > Fix For: 4.0 > > Time Spent: 10m > Remaining Estimate: 0h > > {{StreamSession#prepareAsync()}} executes, as the name implies, > asynchronously from the IO thread: this opens up for race conditions between > the sending of the {{PrepareSynAckMessage}} and the call to > {{StreamSession#maybeCompleted()}}. I.e., the following could happen: > 1) Node A sends {{PrepareSynAckMessage}} from the {{prepareAsync()}} thread. > 2) Node B receives it and starts streaming. > 3) Node A receives the streamed file and sends {{ReceivedMessage}}. > 4) At this point, if this was the only file to stream, both nodes are ready > to close the session via {{maybeCompleted()}}, but: > a) Node A will call it twice from both the IO thread and the thread at #1, > closing the session and its channels. > b) Node B will attempt to send a {{CompleteMessage}}, but will fail because > the session has been closed in the meantime. > There are other subtle variations of the pattern above, depending on the > order of concurrently sent/received messages. > I believe the best fix would be to modify the message exchange so that: > 1) Only the "follower" is allowed to send the {{CompleteMessage}}. > 2) Only the "initiator" is allowed to close the session and its channels > after receiving the {{CompleteMessage}}. > By doing so, the message exchange logic would be easier to reason about, > which is overall a win anyway. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org