[jira] [Commented] (TINKERPOP-1674) Traversals reference elements after deletion
[ https://issues.apache.org/jira/browse/TINKERPOP-1674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16383549#comment-16383549 ] stephen mallette commented on TINKERPOP-1674: - I was never able to make much headway with this one. The example code was nice, but my Scala skills don't make it easy to follow. Is this still an issue given the time that has passed? If so, barring some other representation of the error, I'm not sure we'll easily get to the bottom of this. > Traversals reference elements after deletion > > > Key: TINKERPOP-1674 > URL: https://issues.apache.org/jira/browse/TINKERPOP-1674 > Project: TinkerPop > Issue Type: Bug > Components: neo4j >Affects Versions: 3.2.3, 3.2.4 > Environment: Demonstrated on Ubuntu, OSX >Reporter: SmedbergM >Priority: Major > > In a multiprocessor environment, a traversal will sometimes reference > vertices which another thread/processor has already deleted. This causes the > entire traversal to fail in an unrecoverable fashion and throw an uncaught > exception. > MWE: https://github.com/SmedbergM/neo4j-deletion-error > Gist containing logging output: > https://gist.github.com/SmedbergM/5fcf0d98a255e7d346b85b98bcc1ec0d > This error has cropped up persistently over several months/releases (dating > back to 3.1.x or earlier). I have not tried to diff back/bisect to find > introduction time of the behavior. -- This message was sent by Atlassian JIRA (v7.6.3#76005)
[jira] [Commented] (TINKERPOP-1674) Traversals reference elements after deletion
[ https://issues.apache.org/jira/browse/TINKERPOP-1674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16014024#comment-16014024 ] SmedbergM commented on TINKERPOP-1674: -- I did indeed have to do a lot to reliably make this happen. (The code is abstracted and significantly simplified from how we originally observed the problem in production, using an async HTTP server library.) I'm not sure how much work it would be to reproduce using less machinery; as the logs show, it can be hundreds of transactions before a stale reference is encountered. > Traversals reference elements after deletion > > > Key: TINKERPOP-1674 > URL: https://issues.apache.org/jira/browse/TINKERPOP-1674 > Project: TinkerPop > Issue Type: Bug > Components: neo4j >Affects Versions: 3.2.3, 3.2.4 > Environment: Demonstrated on Ubuntu, OSX >Reporter: SmedbergM > > In a multiprocessor environment, a traversal will sometimes reference > vertices which another thread/processor has already deleted. This causes the > entire traversal to fail in an unrecoverable fashion and throw an uncaught > exception. > MWE: https://github.com/SmedbergM/neo4j-deletion-error > Gist containing logging output: > https://gist.github.com/SmedbergM/5fcf0d98a255e7d346b85b98bcc1ec0d > This error has cropped up persistently over several months/releases (dating > back to 3.1.x or earlier). I have not tried to diff back/bisect to find > introduction time of the behavior. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
[jira] [Commented] (TINKERPOP-1674) Traversals reference elements after deletion
[ https://issues.apache.org/jira/browse/TINKERPOP-1674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16012200#comment-16012200 ] stephen mallette commented on TINKERPOP-1674: - I looked at your code a bit - seems like you had to do a lot to get this to crop up. I don't imagine there's a way to make this happen in a more simplistic fashion? Perhaps you've already tried this but If it is something related to one thread deleting a vertex that another thread references, couldn't this example be simplified to just that scenario? > Traversals reference elements after deletion > > > Key: TINKERPOP-1674 > URL: https://issues.apache.org/jira/browse/TINKERPOP-1674 > Project: TinkerPop > Issue Type: Bug > Components: neo4j >Affects Versions: 3.2.3, 3.2.4 > Environment: Demonstrated on Ubuntu, OSX >Reporter: SmedbergM > > In a multiprocessor environment, a traversal will sometimes reference > vertices which another thread/processor has already deleted. This causes the > entire traversal to fail in an unrecoverable fashion and throw an uncaught > exception. > MWE: https://github.com/SmedbergM/neo4j-deletion-error > Gist containing logging output: > https://gist.github.com/SmedbergM/5fcf0d98a255e7d346b85b98bcc1ec0d > This error has cropped up persistently over several months/releases (dating > back to 3.1.x or earlier). I have not tried to diff back/bisect to find > introduction time of the behavior. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
