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Caleb Rackliffe commented on CASSANDRA-19400: --------------------------------------------- Hey [~arkn98]! I think the easiest way to do this would be for {{filterForQuery()}} to only consider endpoints at {{UNKNOWN}} if there aren't enough {{BUILD_SUCCEEDED}} replicas returned to the initial {{queryableEndpoints}}. If we make the change there, it will apply to all index implementations, as it should. The {{Status}} enum isn't specific to SAI. Actually, while we're at it, we should also have {{CassandraIndex}} implement {{isQueryable()}} to mimic {{StorageAttachedIndex#isQueryable()}}. There's no reason for the legacy 2i implementation not to take advantage of the {{IndexStatusManager}} and avoid availability gaps when its indexes are building on a node(s). This has been on my TODO list for a while, but I'm glad to review/provide any guidance you need if you'd like to take a swing at it. > IndexStatusManager needs to prioritize SUCCESS over UNKNOWN states to > maximize availability > ------------------------------------------------------------------------------------------- > > Key: CASSANDRA-19400 > URL: https://issues.apache.org/jira/browse/CASSANDRA-19400 > Project: Cassandra > Issue Type: Bug > Components: Feature/SAI > Reporter: Caleb Rackliffe > Priority: Low > Fix For: 5.0.x, 5.x > > > {{IndexStatusManager}} is responsible for knowing what SAI indexes are > queryable across the ring, endpoint by endpoint. There are two statuses that > SAI treats as queryable, but it should not treat them equally. > {{BUILD_SUCCEEDED}} means the index is definitely available and should be > able to serve queries without issue. {{UNKNOWN}} indicates that the status of > the index hasn’t propagated yet to this coordinator. It may be just fine, or > it may not be. If it isn’t a query will not return incorrect results, but it > will fail. If there are enough {{BUILD_SUCCEEDED}} replicas, we should ignore > {{UNKNOWN}} replicas and maximize availability. If the UNKNOWN replica is > going to become {{BUILD_SUCCEEDED}} shortly, it will happily start taking > requests at that point and spread the load. If not, we’ll avoid futile > attempts to query it too early. -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org