Which version of ZK? -----Original Message----- From: Nick Patania [mailto:[email protected]] Sent: Friday, February 11, 2011 6:10 PM To: [email protected] Subject: Re: tickTime and sessionTimeout
A single server. I've intentionally made it trivial to demonstrate the behavior. If I increase the timeout, the issue goes away. On Fri, Feb 11, 2011 at 6:00 PM, Fournier, Camille F. [Tech] <[email protected]> wrote: > What is your ZooKeeper setup here? And do you continue to see this issue if > you increase your session timeout? > > C > > -----Original Message----- > From: Nick Patania [mailto:[email protected]] > Sent: Friday, February 11, 2011 5:24 PM > To: [email protected] > Subject: Re: tickTime and sessionTimeout > > Patrick, thanks for your input. > > I have rerun the test several times now while logging GC on the server > and running ping from CLIENT_1: > > - No GC happens on the server during the period of interest (a > couple of young generation runs happen before I kill HOST_0, and they > complete in under 3ms). > - Round trip times for ping from CLIENT_1 are consistently under > 250us throughout. > > Regarding client GC -- I can consistently reproduce this using a C > client. Regarding the theory of swapping on CLIENT_1 -- if that were > the cause, the problem wouldn't be 100% reproducible. I also looked > through the client log for SESSION_1 -- I see "Got ping response ... > after 1ms" repeatedly, followed by "Client session timed out, have not > heard from server in 666ms"... > > On Fri, Feb 11, 2011 at 1:46 PM, Patrick Hunt <[email protected]> wrote: >> Those are pretty short timeouts, many sources of delay could be >> causing this. Network jitter/latency, GC/swap (server or client), IO >> write latency, etc... See if any of this might be your issue: >> https://cwiki.apache.org/confluence/display/ZOOKEEPER/Troubleshooting >> >> I can clearly see this sequence in your log for session1: >> >> --- >> 2011-02-11 14:18:52,672 - sessionid:SESSION_1 type:ping >> >> 2011-02-11 14:18:54,502 - Expiring session SESSION_1, timeout of 1000ms >> exceeded >> >> 2011-02-11 14:18:55,011 - Processing request:: sessionid:SESSION_1 type:ping >> --- >> >> from the looks of it session 1 doesn't send a ping to the server for >> ~2.5 seconds, as a result it's expired. >> >> You should also look at your session 1 client log and see what it's >> view of the world is like. (is it gc/swapping?). Use the "stat" 4 >> letter word to see the server's request processing latency, see if >> that's high (higer than the timeout is bad news). Again, checkout the >> troubleshooting guide. >> >> Patrick >> >> ps please use pastebin or attachment, otw the formatting of wrecked >> and it's harder to read the log >> >> On Fri, Feb 11, 2011 at 6:41 AM, Nick Patania >> <[email protected]> wrote: >>> This is the portion that seems relevant. For readability, I replaced >>> the host and session for the host that I kill with HOST_0 and >>> SESSION_0 (I expect these to timeout). The client that should be >>> healthy is HOST_1 and SESSION_1. >>> >>> >>> 2011-02-11 14:18:51,901 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_0 type:ping cxid:0xfffffffffffffffe >>> zxid:0xfffffffffffffffe txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:51,901 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@160] - sessionid:SESSION_0 >>> type:ping cxid:0xfffffffffffffffe zxid:0xfffffffffffffffe >>> txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,005 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_1 type:ping cxid:0xfffffffffffffffe >>> zxid:0xfffffffffffffffe txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,005 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@160] - sessionid:SESSION_1 >>> type:ping cxid:0xfffffffffffffffe zxid:0xfffffffffffffffe >>> txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,339 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_1 type:ping cxid:0xfffffffffffffffe >>> zxid:0xfffffffffffffffe txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,339 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@160] - sessionid:SESSION_1 >>> type:ping cxid:0xfffffffffffffffe zxid:0xfffffffffffffffe >>> txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,672 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_1 type:ping cxid:0xfffffffffffffffe >>> zxid:0xfffffffffffffffe txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:52,672 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@160] - sessionid:SESSION_1 >>> type:ping cxid:0xfffffffffffffffe zxid:0xfffffffffffffffe >>> txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:53,002 - INFO [SessionTracker:ZooKeeperServer@314] - >>> Expiring session SESSION_0, timeout of 1000ms exceeded >>> 2011-02-11 14:18:53,002 - INFO >>> [ProcessThread:-1:PrepRequestProcessor@387] - Processed session >>> termination for sessionid: SESSION_0 >>> 2011-02-11 14:18:53,010 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_0 type:closeSession cxid:0x0 zxid:0x103 txntype:-11 >>> reqpath:n/a >>> 2011-02-11 14:18:53,010 - INFO [SyncThread:0:NIOServerCnxn@1435] - >>> Closed socket connection for client /HOST_0:34618 which had sessionid >>> SESSION_0 >>> 2011-02-11 14:18:54,502 - INFO [SessionTracker:ZooKeeperServer@314] - >>> Expiring session SESSION_1, timeout of 1000ms exceeded >>> 2011-02-11 14:18:54,502 - INFO >>> [ProcessThread:-1:PrepRequestProcessor@387] - Processed session >>> termination for sessionid: SESSION_1 >>> 2011-02-11 14:18:55,011 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_1 type:ping cxid:0xfffffffffffffffe >>> zxid:0xfffffffffffffffe txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:55,011 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@160] - sessionid:SESSION_1 >>> type:ping cxid:0xfffffffffffffffe zxid:0xfffffffffffffffe >>> txntype:unknown reqpath:n/a >>> 2011-02-11 14:18:55,011 - INFO >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn$Factory@251] >>> - Accepted socket connection from /HOST_1:40556 >>> 2011-02-11 14:18:55,019 - DEBUG >>> [SyncThread:0:FinalRequestProcessor@78] - Processing request:: >>> sessionid:SESSION_1 type:closeSession cxid:0x0 zxid:0x104 txntype:-11 >>> reqpath:n/a >>> 2011-02-11 14:18:55,019 - DEBUG >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:ZooKeeperServer@590] - >>> Dropping request: No session with sessionid SESSION_1 exists, probably >>> expired and removed >>> 2011-02-11 14:18:55,019 - INFO [SyncThread:0:NIOServerCnxn@1435] - >>> Closed socket connection for client /HOST_1:40555 which had sessionid >>> SESSION_1 >>> 2011-02-11 14:18:55,020 - DEBUG [SyncThread:0:NIOServerCnxn@1451] - >>> ignoring exception during output shutdown >>> java.net.SocketException: Transport endpoint is not connected >>> at sun.nio.ch.SocketChannelImpl.shutdown(Native Method) >>> at >>> sun.nio.ch.SocketChannelImpl.shutdownOutput(SocketChannelImpl.java:651) >>> at sun.nio.ch.SocketAdaptor.shutdownOutput(SocketAdaptor.java:368) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn.closeSock(NIOServerCnxn.java:1447) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn.close(NIOServerCnxn.java:1412) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn$Factory.closeSessionWithoutWakeup(NIOServerCnxn.java:343) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn$Factory.closeSession(NIOServerCnxn.java:330) >>> at >>> org.apache.zookeeper.server.FinalRequestProcessor.processRequest(FinalRequestProcessor.java:133) >>> at >>> org.apache.zookeeper.server.SyncRequestProcessor.flush(SyncRequestProcessor.java:161) >>> at >>> org.apache.zookeeper.server.SyncRequestProcessor.run(SyncRequestProcessor.java:98) >>> 2011-02-11 14:18:55,021 - DEBUG [SyncThread:0:NIOServerCnxn@1459] - >>> ignoring exception during input shutdown >>> java.net.SocketException: Transport endpoint is not connected >>> at sun.nio.ch.SocketChannelImpl.shutdown(Native Method) >>> at >>> sun.nio.ch.SocketChannelImpl.shutdownInput(SocketChannelImpl.java:640) >>> at sun.nio.ch.SocketAdaptor.shutdownInput(SocketAdaptor.java:360) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn.closeSock(NIOServerCnxn.java:1455) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn.close(NIOServerCnxn.java:1412) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn$Factory.closeSessionWithoutWakeup(NIOServerCnxn.java:343) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn$Factory.closeSession(NIOServerCnxn.java:330) >>> at >>> org.apache.zookeeper.server.FinalRequestProcessor.processRequest(FinalRequestProcessor.java:133) >>> at >>> org.apache.zookeeper.server.SyncRequestProcessor.flush(SyncRequestProcessor.java:161) >>> at >>> org.apache.zookeeper.server.SyncRequestProcessor.run(SyncRequestProcessor.java:98) >>> 2011-02-11 14:18:55,022 - WARN >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn$Factory@272] >>> - Ignoring unexpected runtime exception >>> java.nio.channels.CancelledKeyException >>> at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:55) >>> at sun.nio.ch.SelectionKeyImpl.readyOps(SelectionKeyImpl.java:69) >>> at >>> org.apache.zookeeper.server.NIOServerCnxn$Factory.run(NIOServerCnxn.java:241) >>> 2011-02-11 14:18:55,023 - DEBUG >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn@735] - >>> Session establishment request from client /HOST_1:40556 client's >>> lastZxid is 0x0 >>> 2011-02-11 14:18:55,023 - INFO >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn@770] - Client >>> attempting to renew session SESSION_1 at /HOST_1:40556 >>> 2011-02-11 14:18:55,024 - INFO >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn@1573] - >>> Invalid session SESSION_1 for client /HOST_1:40556, probably expired >>> 2011-02-11 14:18:55,025 - WARN >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn@634] - >>> EndOfStreamException: Unable to read additional data from client >>> sessionid SESSION_1, likely client has closed socket >>> 2011-02-11 14:18:55,025 - INFO >>> [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:4799:NIOServerCnxn@1435] - >>> Closed socket connection for client /HOST_1:40556 which had sessionid >>> SESSION_1 >>> >>> >>> On Thu, Feb 10, 2011 at 8:11 PM, Benjamin Reed <[email protected]> wrote: >>>> do you see anything in the server log? >>>> >>>> ben >>>> >>>> On 02/10/2011 03:16 PM, Patania, Nick wrote: >>>>> >>>>> Hello, >>>>> >>>>> I run the following test: >>>>> >>>>> >>>>> * Two clients connect to a zookeeper server; the tickTime on the >>>>> server is 500, and the sessionTimeout on the client is 1000. >>>>> >>>>> * Kill the host running one of the clients. >>>>> >>>>> * The second client receives a session timeout. >>>>> >>>>> Is there any reason why this might happen? >>>>> >>>>> Thanks >>>>> Nick Patania >>>>> >>>>> >>>>> -------------------------------------------------------------------------- >>>>> NOTICE: Morgan Stanley is not acting as a municipal advisor and the >>>>> opinions or views contained herein are not intended to be, and do not >>>>> constitute, advice within the meaning of Section 975 of the Dodd-Frank >>>>> Wall >>>>> Street Reform and Consumer Protection Act. If you have received this >>>>> communication in error, please destroy all electronic and paper copies and >>>>> notify the sender immediately. Mistransmission is not intended to waive >>>>> confidentiality or privilege. Morgan Stanley reserves the right, to the >>>>> extent permitted under applicable law, to monitor electronic >>>>> communications. >>>>> This message is subject to terms available at the following link: >>>>> http://www.morganstanley.com/disclaimers. If you cannot access these >>>>> links, >>>>> please notify us by reply message and we will send the contents to you. By >>>>> messaging with Morgan Stanley you consent to the foregoing. >>>> >>>> >>> >> >
