kotman12 opened a new pull request, #3477: URL: https://github.com/apache/solr/pull/3477
--------- https://issues.apache.org/jira/browse/SOLR-17863 # Description [SOLR-16713](https://issues.apache.org/jira/browse/SOLR-16713) introduced a race condition into the perSegmentFingerprintCache as it changed it from the [thread-safe guava implementation to the thread-UNSAFE WeakHashMap](https://github.com/apache/solr/commit/375ac647ad507638686848c549c30e6c077dca1b#diff-3bf44f923643744a743460bb0f64301618dd7529a602d945fe2f7f193d4cdde0). This flew under the radar for some time because this map previously had very little contention between threads. However after [SOLR-17756](https://issues.apache.org/jira/browse/SOLR-17756) we turbo-charged the race after parallelizing at a much more granular level upstream of this call. The net effect is that WeakHashMap:put can get stuck in an infinite-loop (probably due to a cycle in the underlying linked-list that it modifies): # Solution Please provide a short description of the approach taken to implement your solution. # Tests It is hard to recreate this reliably. I've been able to reproduce by increasing the amount of segments written by `SolrIndexFingerprintTest` to ~500 although this does take some time. # Checklist Please review the following and check all that apply: - [X] I have reviewed the guidelines for [How to Contribute](https://github.com/apache/solr/blob/main/CONTRIBUTING.md) and my code conforms to the standards described there to the best of my ability. - [X] I have created a Jira issue and added the issue ID to my pull request title. - [X] I have given Solr maintainers [access](https://help.github.com/en/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork) to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation) - [X] I have developed this patch against the `main` branch. - [X] I have run `./gradlew check`. - [X ] I have added tests for my changes. - [ ] I have added documentation for the [Reference Guide](https://github.com/apache/solr/tree/main/solr/solr-ref-guide) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
