Hi, shangwen 这应该是AppendOnlyWriter的一个bug[1]， 在1.10.1/1.11-SNAPSHOT(master)中已经修复. 用1.10.1或master分支就好了，目前1.10.1还未发布，我了解到的1.10.1社区正在准备发布中。 如果急需修复，你可以参考1.10.1分支的代码。
Best, Leonard [1]https://issues.apache.org/jira/browse/FLINK-16281 <https://issues.apache.org/jira/browse/FLINK-16281> [2]https://github.com/apache/flink/tree/release-1.10 <https://github.com/apache/flink/tree/release-1.10> > 在 2020年3月23日，11:05，shangwen <[email protected]> 写道： > > 我们在测试环境测试JDBC写入postgresql的场景，用tcpkill模拟链接被关闭的情况，测试对异常的兼容性，我们发现一直打印类似的日志 > > > 2020-03-20 21:16:21.247 [jdbc-upsert-output-format-thread-1] ERROR > org.apache.flink.api.java.io.jdbc.JDBCUpsertOutputFormat - JDBC > executeBatch error, retry times = 1 > org.postgresql.util.PSQLException: This connection has been closed. > at org.postgresql.jdbc.PgConnection.checkClosed(PgConnection.java:857) > at org.postgresql.jdbc.PgConnection.getAutoCommit(PgConnection.java:817) > at > org.postgresql.jdbc.PgStatement.internalExecuteBatch(PgStatement.java:813) > at org.postgresql.jdbc.PgStatement.executeBatch(PgStatement.java:873) > at > org.postgresql.jdbc.PgPreparedStatement.executeBatch(PgPreparedStatement.java:1569) > at > org.apache.flink.api.java.io.jdbc.writer.AppendOnlyWriter.executeBatch(AppendOnlyWriter.java:62) > at > org.apache.flink.api.java.io.jdbc.JDBCUpsertOutputFormat.flush(JDBCUpsertOutputFormat.java:159) > at > org.apache.flink.api.java.io.jdbc.JDBCUpsertOutputFormat.lambda$open$0(JDBCUpsertOutputFormat.java:124) > at > java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) > at java.lang.Thread.run(Thread.java:748) > > > > 从日志上看来，链接被关闭，只会导致重试一次，这里是Flink的重试代码 > //JDBCUpsertOutputFormat.javapublic synchronized void flush() throws > Exception { > checkFlushException(); > > for (int i = 1; i <= maxRetryTimes; i++) { > try { > jdbcWriter.executeBatch(); > batchCount = 0; > break; > } catch (SQLException e) { > LOG.error("JDBC executeBatch error, retry times = {}", i, e); > if (i >= maxRetryTimes) { > throw e; > } > Thread.sleep(1000 * i); > } > } > } > > > 通过远程debug分析，在第一次执行 > JDBCUpsertOutputFormat.flush > -> AppendOnlyWriter.executeBatch > ... > -> PgConnection.getAutoCommit > 抛出PSQLException: This connection has been closed时，batchStatements在这之前已经被清空 > // PgStatement.java private BatchResultHandler internalExecuteBatch() throws > SQLException { // Construct query/parameter arrays. > transformQueriesAndParameters(); // Empty arrays should be passed to > toArray // see http://shipilev.net/blog/2016/arrays-wisdom-ancients/ > Query[] queries = batchStatements.toArray(new Query[0]); ParameterList[] > parameterLists = batchParameters.toArray(new ParameterList[0]); > batchStatements.clear(); // 这里已经被清空 batchParameters.clear(); ... if > (connection.getAutoCommit()) { // 抛出异常 flags |= > QueryExecutor.QUERY_SUPPRESS_BEGIN; } ... } > > > 所以在Flink第二次重试执行这段代码的时候jdbcWriter.executeBatch的时候，batchStatements已经为Empty并直接返回了，导致Flink认为是成功的，这样会导致其实语句没有被执行？ > // PgStatement.java public int[] executeBatch() throws SQLException { > checkClosed(); closeForNextExecution(); if (batchStatements == null || > batchStatements.isEmpty()) { //这里就直接返回了 return new int[0]; } return > internalExecuteBatch().getUpdateCount(); } > > > 目前的想法是，当我出现异常捕获的时候，在重试之前，判断这个链接是否已经被关闭，如果已经被关闭，则重新open，不知道大家有啥看法，这是我提的issue > https://issues.apache.org/jira/browse/FLINK-16708
