[jira] [Created] (BEAM-6475) SQL Connection leak when using streaming pipeline

["Jonathan Perron (JIRA)" <ji...@apache.org>]

Jonathan Perron created BEAM-6475:
-------------------------------------

             Summary: SQL Connection leak when using streaming pipeline
                 Key: BEAM-6475
                 URL: https://issues.apache.org/jira/browse/BEAM-6475
             Project: Beam
          Issue Type: Bug
          Components: io-java-jdbc
    Affects Versions: 2.7.0
            Reporter: Jonathan Perron
            Assignee: Jean-Baptiste Onofré


We have a streaming pipeline running on Dataflow which writes data to a PostgreSQL instance hosted on Cloud SQL. This database is suffering from connection increases on a regular but unpredictable basis without particular reason.

Latest example was on Friday 18th January 2019:

!image-2019-01-21-08-50-13-932.png!

(The spike in the middle is unrelated to this issue as it belongs to a periodic batch pipeline).

Investigations in the GCP logs provides following warning happening at the same time as the connection increases:

_2019-01-18 05:52:11.067 HNEC Can't verify serialized elements of type SessionData have well defined equals method. This may produce incorrect results on some PipelineRunner_

This log line is present 13 times in a very short interval, between 05:52:11:11.067 and 05:52:11:11.126.

The SessionData are custom objects which inherits java.io.Serializable. They are written to the PostgreSQL database using:

 _pipeline.apply(JdbcIO.<SessionData>write()_
 _.withDataSourceConfiguration(ExtractFunctions.getDataSourceConfiguration(options.instance, options.db_login,options.db_password))_
 _.withStatement("SQL_STATEMENT")_
 _.withPreparedStatementSetter(new InsertSessionPrepareStatementSetter()));_

 Looking at pg_stat_activity in the psql instance, all connections are used. Using _select * from pg_stat_activity where state = 'idle' and query = 'ROLLBACK';_, no result is returned.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)