[ https://issues.apache.org/jira/browse/ZOOKEEPER-737?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Patrick Hunt updated ZOOKEEPER-737: ----------------------------------- Status: Patch Available (was: Open) > some 4 letter words may fail with netcat (nc) > --------------------------------------------- > > Key: ZOOKEEPER-737 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-737 > Project: Zookeeper > Issue Type: Bug > Components: server > Affects Versions: 3.3.0 > Reporter: Patrick Hunt > Assignee: Mahadev konar > Priority: Blocker > Fix For: 3.3.1, 3.4.0 > > Attachments: ZOOKEEPER-737.patch, ZOOKEEPER-737.patch, > ZOOKEEPER-737.patch, ZOOKEEPER-737.patch > > > nc closes the write channel as soon as it's sent it's information, for > example "echo stat|nc localhost 2181" > in general this is fine, however the server code will close the socket as > soon as it receives notice that nc has > closed it's write channel. if not all the 4 letter word result has been > written back to the client yet, this will cause > some or all of the result to be lost - ie the client will not see the full > result. this was introduced in 3.3.0 as part > of a change to reduce blocking of the selector by long running 4letter words. > here's an example of the logs from the server during this > echo -n stat | nc localhost 2181 > 2010-04-09 21:55:36,124 - INFO > [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioservercnxn$fact...@251] - > Accepted socket connection from /127.0.0.1:42179 > 2010-04-09 21:55:36,124 - INFO > [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioserverc...@968] - Processing > stat command from /127.0.0.1:42179 > 2010-04-09 21:55:36,125 - WARN > [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioserverc...@606] - > EndOfStreamException: Unable to read additional data from client sessionid > 0x0, likely client has closed socket > 2010-04-09 21:55:36,125 - INFO > [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioserverc...@1286] - Closed > socket connection for client /127.0.0.1:42179 (no session established for > client) > [ph...@gsbl90850 zookeeper-3.3.0]$ 2010-04-09 21:55:36,126 - ERROR > [Thread-15:nioserverc...@422] - Unexpected Exception: > java.nio.channels.CancelledKeyException > at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:55) > at sun.nio.ch.SelectionKeyImpl.interestOps(SelectionKeyImpl.java:59) > at > org.apache.zookeeper.server.NIOServerCnxn.sendBuffer(NIOServerCnxn.java:395) > at > org.apache.zookeeper.server.NIOServerCnxn$SendBufferWriter.checkFlush(NIOServerCnxn.java:907) > at > org.apache.zookeeper.server.NIOServerCnxn$SendBufferWriter.flush(NIOServerCnxn.java:945) > at java.io.BufferedWriter.flush(BufferedWriter.java:236) > at java.io.PrintWriter.flush(PrintWriter.java:276) > at > org.apache.zookeeper.server.NIOServerCnxn$2.run(NIOServerCnxn.java:1089) > 2010-04-09 21:55:36,126 - ERROR [Thread-15:nioservercnxn$factor...@82] - > Thread Thread[Thread-15,5,main] died > java.nio.channels.CancelledKeyException > at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:55) > at sun.nio.ch.SelectionKeyImpl.interestOps(SelectionKeyImpl.java:64) > at > org.apache.zookeeper.server.NIOServerCnxn$SendBufferWriter.wakeup(NIOServerCnxn.java:927) > at > org.apache.zookeeper.server.NIOServerCnxn$SendBufferWriter.checkFlush(NIOServerCnxn.java:909) > at > org.apache.zookeeper.server.NIOServerCnxn$SendBufferWriter.flush(NIOServerCnxn.java:945) > at java.io.BufferedWriter.flush(BufferedWriter.java:236) > at java.io.PrintWriter.flush(PrintWriter.java:276) > at > org.apache.zookeeper.server.NIOServerCnxn$2.run(NIOServerCnxn.java:1089) -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.