mlbiscoc opened a new pull request, #2935: URL: https://github.com/apache/solr/pull/2935
https://issues.apache.org/jira/browse/SOLR-17519 # Description In `BaseHttpClusterStateProvider` if all initially passed nodes except for 1 go down, then CSP will only be aware of the 1 live node. If that node were to go down and any of the other initially passed nodes were to recover, CSP would not be able to connect to get latest cluster state of live nodes because it only holds the address of the now downed node. # Solution CSP holds immutable `initialNodes` and `knownNodes` which always have the latest set of live nodes but never removes initial set of live nodes to keep it resilient. Now if the case above were to occur, CSP would still be able to get cluster state and latest set of live nodes because known nodes is always aware of the initial set of live nodes. Known nodes can also hold new nodes that are added to the cluster after CSP initializion but those are removable unlike the initial nodes. # Tests `testClusterStateProviderDownedLiveNodes` tests the above test case and used to fail. `testClusterStateProviderDownedKnownHosts` tests known nodes and asserts it always holds all initial sets of nodes even if nodes are down `testClusterStateProviderKnownHostsWithNewHost` tests known nodes with a 3rd added new host after CSP is initialized which is removable but initial nodes are always still present to be reachable by CSP. # Checklist Please review the following and check all that apply: - [ ] 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. - [ ] I have created a Jira issue and added the issue ID to my pull request title. - [ ] 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) - [ ] I have developed this patch against the `main` branch. - [ ] I have run `./gradlew check`. - [ ] 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: issues-unsubscr...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org
