yaooqinn commented on issue #786: URL: https://github.com/apache/incubator-kyuubi/issues/786#issuecomment-878858464
For engine, we'd call it service discovery, not load balancing. The engine discovery logic is better to bind with client requests, a.k.a, JDBC connections, as an engine is stateful with cache tables, udf, etc. We already have implemented 3 share levels, CONNECTION/USER/SERVER for different kinds of usage scenarios. - For CONNECTION mode, the engine and all states are within a JDBC connection. - For USER mode, the engine and all states might/could share across all JDBC connections of a user with a `subDomain` if any. For `The last engine is acquired by default`, it's a potential bug since `1.2.0-rc`s as a distributed lock for engine creation. When an engine is created but killed forcefully and externally, the service uri of this engine will not get cleared. And another thread might get a malformed engine after it gains the lock. For this part, I think we need to introduce a retry and recreation of engine -- 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]
