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Michael Han commented on ZOOKEEPER-2737: ---------------------------------------- Committed. Master: https://github.com/apache/zookeeper/commit/d8adc547f9856747905b7d46450f13fa98df147f 3.5: https://github.com/apache/zookeeper/commit/5c356f5a47402c000b5e206a536273afc75de883 > NettyServerCnxFactory leaks connection if exception happens while writing to > a channel. > --------------------------------------------------------------------------------------- > > Key: ZOOKEEPER-2737 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2737 > Project: ZooKeeper > Issue Type: Bug > Components: server > Affects Versions: 3.5.2 > Reporter: Michael Han > Assignee: Michael Han > Priority: Critical > Labels: connection, netty, server > Fix For: 3.5.3, 3.6.0 > > > Found this while debugging occasionally failed unit tests. Currently we do > this if exception occurs during writing to a channel with Netty: > {code} > @Override > public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent > e) > throws Exception > { > LOG.warn("Exception caught " + e, e.getCause()); > NettyServerCnxn cnxn = (NettyServerCnxn) ctx.getAttachment(); > if (cnxn != null) { > if (LOG.isDebugEnabled()) { > LOG.debug("Closing " + cnxn); > cnxn.close(); > } > } > } > {code} > So the connection is only closed when debug mode is enabled. This is > problematic as lots of clean up code is abstracted inside the close and > without proper close the connection we are leaking resources. > [Commit > log|https://github.com/apache/zookeeper/blob/master/src/java/main/org/apache/zookeeper/server/NettyServerCnxnFactory.java#L147] > indicates the issue exists since day 1 with ZOOKEEPER-733. Note the original > patch uploaded to ZOOKEEPER-733 has this close call in right place, and the > call gets moved around during iteration of the patches w/o gets noticed. -- This message was sent by Atlassian JIRA (v6.3.15#6346)