[ 
https://issues.apache.org/jira/browse/FLINK-19723?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17222726#comment-17222726
 ] 

shizhengchao commented on FLINK-19723:
--------------------------------------

Hi [~jark], after testing, this is not a bug, could you close the issue?:D

Generally, after executing executeBatch in jdbc, regardless of success or 
failure, the list of preparedStatements  will be cleared

> The retry mechanism of jdbc connector has the risk of data duplication
> ----------------------------------------------------------------------
>
>                 Key: FLINK-19723
>                 URL: https://issues.apache.org/jira/browse/FLINK-19723
>             Project: Flink
>          Issue Type: Bug
>          Components: Connectors / JDBC
>    Affects Versions: 1.11.1
>            Reporter: shizhengchao
>            Assignee: shizhengchao
>            Priority: Major
>              Labels: pull-request-available
>
> for example,  if statement.executeBatch() failur for some reason, but the 
> "statement" was not closed in the retry, there is a risk of data duplication:
> {code:java}
> for (int i = 1; i <= executionOptions.getMaxRetries(); i++) {
>       try {
>               attemptFlush();
>               batchCount = 0;
>               break;
>       } catch (SQLException e) {
>               LOG.error("JDBC executeBatch error, retry times = {}", i, e);
>               if (i >= executionOptions.getMaxRetries()) {
>                       throw new IOException(e);
>               }
>               try {
>                       if 
> (!connection.isValid(CONNECTION_CHECK_TIMEOUT_SECONDS)) {
>                               connection = 
> connectionProvider.reestablishConnection();
>                                 jdbcStatementExecutor.closeStatements();
>                               
> jdbcStatementExecutor.prepareStatements(connection);
>                       }
>               } catch (Exception excpetion) {
>                       LOG.error("JDBC connection is not valid, and 
> reestablish connection failed.", excpetion);
>                       throw new IOException("Reestablish JDBC connection 
> failed", excpetion);
>               }
>               try {
>                       Thread.sleep(1000 * i);
>               } catch (InterruptedException ex) {
>                       Thread.currentThread().interrupt();
>                       throw new IOException("unable to flush; interrupted 
> while doing another attempt", e);
>               }
>       }
> }
> {code}
> the correct code should be:
> {code:java}
> try {
>                       if 
> (!connection.isValid(CONNECTION_CHECK_TIMEOUT_SECONDS)) {
>                               connection = 
> connectionProvider.reestablishConnection();
>                       }
>                         jdbcStatementExecutor.closeStatements();
>                       jdbcStatementExecutor.prepareStatements(connection);
>               } catch (Exception excpetion) {
>                       LOG.error("JDBC connection is not valid, and 
> reestablish connection failed.", excpetion);
>                       throw new IOException("Reestablish JDBC connection 
> failed", excpetion);
>               }
> {code}



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to