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ASF GitHub Bot commented on FLINK-9794: --------------------------------------- Github user jrthe42 commented on the issue: https://github.com/apache/flink/pull/6301 Hi @sihuazhou snapshots are executed in a separated thread, you can check this : https://github.com/apache/flink/blob/53e6657658bc750b78c32e91fa7e2c02e8c54e33/flink-runtime/src/main/java/org/apache/flink/runtime/taskmanager/Task.java#L1212 > JDBCOutputFormat does not consider idle connection and multithreads > synchronization > ----------------------------------------------------------------------------------- > > Key: FLINK-9794 > URL: https://issues.apache.org/jira/browse/FLINK-9794 > Project: Flink > Issue Type: Bug > Components: Streaming Connectors > Affects Versions: 1.4.0, 1.5.0 > Reporter: wangsan > Priority: Major > Labels: pull-request-available > > Current implementation of JDBCOutputFormat has two potential problems: > 1. The Connection was established when JDBCOutputFormat is opened, and will > be used all the time. But if this connection lies idle for a long time, the > database will force close the connection, thus errors may occur. > 2. The flush() method is called when batchCount exceeds the threshold, but it > is also called while snapshotting state. So two threads may modify upload and > batchCount, but without synchronization. > We need fix these two problems to make JDBCOutputFormat more reliable. -- This message was sent by Atlassian JIRA (v7.6.3#76005)