[ https://issues.apache.org/jira/browse/ZOOKEEPER-2893?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Patrick Hunt resolved ZOOKEEPER-2893. ------------------------------------- Resolution: Fixed Hadoop Flags: Reviewed Fix Version/s: 3.4.12 3.6.0 3.5.4 +1 lgtm. Thanks [~andorm] and [~paulmillar] ! > very poor choice of logging if client fails to connect to server > ---------------------------------------------------------------- > > Key: ZOOKEEPER-2893 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2893 > Project: ZooKeeper > Issue Type: Bug > Components: java client > Affects Versions: 3.4.6, 3.5.3, 3.6.0 > Reporter: Paul Millar > Assignee: Andor Molnar > Fix For: 3.5.4, 3.6.0, 3.4.12 > > > We are using ZooKeeper in our project and have received reports that, when > suffering a networking problem, log files become flooded with messages like: > {quote} > 07 Sep 2017 08:22:00 (System) [] Session 0x45d3151be3600a9 for server null, > unexpected error, closing socket connection and attempting reconnect > java.net.NoRouteToHostException: No route to host > at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > ~[na:1.8.0_131] > at > sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) > ~[na:1.8.0_131] > at > org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361) > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > at > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081) > ~[zookeeper-3.4.6.jar:3.4.6-1569965] > {quote} > Looking at the code that logs this message ({{ClientCnxn}}), there seems to > be quite a few problems here: > # the code logs a stack-trace, even though there is no bug here. In our > project, we treat all logged stack-traces as bugs, > # if the networking issue is not fixed promptly, the log files is flooded > with these message, > # The message is built using {{ClientCnxnSocket#getRemoteSocketAddress}}, yet > in this case, this does not provide the expected information (yielding > {{null}}), > # The log message fails to include a description of what actually went wrong. > (Additionally, the code uses string concatenation rather than templating when > building the message; however, this is an optimisation issue) > My suggestion is that this log entry is updated so that it doesn't log a > stack-trace, but does include some indication why the connection failed. -- This message was sent by Atlassian JIRA (v6.4.14#64029)