[
https://issues.apache.org/jira/browse/FLINK-39403?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
ASF GitHub Bot updated FLINK-39403:
-----------------------------------
Labels: pull-request-available (was: )
> Postgres snapshotting phase might cause transaction leak
> --------------------------------------------------------
>
> Key: FLINK-39403
> URL: https://issues.apache.org/jira/browse/FLINK-39403
> Project: Flink
> Issue Type: Bug
> Components: Flink CDC
> Reporter: Levani Kokhreidze
> Priority: Major
> Labels: pull-request-available
> Attachments: Screenshot 2026-04-03 at 14.07.58.png
>
>
> We observe increase in "idle in transaction" times when using Flink CDC
> (3.4.0 version) with Postgres database. One possible cause might be
>
> {code:java}
> PostgresSnapshotSplitReadTask ->
> PostgresQueryUtils.readTableSplitDataStatement ->
> PostgresQueryUtils.initStatement
> {code}
> initStatement in return disables auto commit for the connection due to
> setting the fetchSize on the statement:
> {code:java}
> private static PreparedStatement initStatement(JdbcConnection jdbc, String
> sql, int fetchSize)
> throws SQLException {
> final Connection connection = jdbc.connection();
> connection.setAutoCommit(false);
> final PreparedStatement statement = connection.prepareStatement(sql);
> statement.setFetchSize(fetchSize);
> return statement;
> } {code}
> There's no explicit commit/rollback calls which might cause the transaction
> leak.
> Attached screenshot shows one of the replica databases showing increase in
> the idle in transaction metric. Table in question had evenly split chunks and
> there was no other process connecting to that database but Flink CDC.
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
