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
Priority: Blocker
Fix For: 3.3.1, 3.4.0
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.
-
If you think it was sent incorrectly contact one of the administrators:
https://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
