when I stop my flink application in standalone cluster, one of the tasks can NOT exit gracefully. And the task managers are lost(or detached?). I can't see them in the web ui. However, the task managers are still running in the slave servers.
What could be the possible cause? My application run Over-window aggregation on a datastream table, the results are written into a custom mysql sink with org.apache.commons.dbcp.BasicDataSource. Close methods are called for the PreparedStatement, Connection, and BasicDataSource within AbstractRichFunction::close()
Is it because of mysql jdbc doesn't handle interrupt propertly? Should I call PreparedStatement::cancel()? I find a similar issue here. Thank you for your help.