LantaoJin commented on pull request #28938: URL: https://github.com/apache/spark/pull/28938#issuecomment-654836968
In my opinion, hive client (metastore clien) is not thread-safe. I don't find any documentation but I find a patch [HIVE-13753](https://issues.apache.org/jira/browse/HIVE-13753) to provide a thread-saft client `SynchronizedMetaStoreClient`. So current implementation of `HiveClientImpl` still uses `getMSC()` to operate with metastore. But I think it's fine even the metastore client is not thread-safe but with R/W locks per DB. "conflicting operations like creating the same table at the same time." is just an example. With the locks, we still can prevent from the conflict operations in client side such as `tableExists("db1.table1")` reture `false`, but another thread is `createTable("db1.table1")`. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org