I
> > > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1115)
> > >
> > >
> > Caused by: java.lang.ClassNotFoundException:
> > org.apache.zookeeper.server.ZooTrace
MG>put zookeeper*.jar on CLASSPATH
> > > at
> > > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1711)
> > >
> > >
> > at
> > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
> > > ... 1 more
> > >
> > >
> > >
> > >
> > > at the same time,the following is also in catalina.out:
> > >
> > >
> > >
> > > INFO: Illegal access: this web application instance has been
> > > stopped already. Could not load
> > > org.apache.zookeeper.server.ZooTrace. The eventual following stack
> > > trace is caused by an error thrown for debugging purposes as well
> > > as to attempt to terminate the thread which caused the illegal
> > > access, and has no functional impact.
> > > java.lang.IllegalStateException at
> > > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1597)
> > >
> > >
> > at
> > org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
> > > at
> > > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1115)
> > >
> > >
> > >
> > >
> > > I searched google and mail list ,couldn't find any solution,please
> > > help me.
> > >
> > >
> > > Enviroment info:
> > >
> > > JDK:1.6.0_45
> > >
> > > Tomcat:7.0.40
> > >
> > > Zookeeper:3.4.5
> >
> > Can you give us any more of the stack trace? It looks like this is
> > happening during shutdown, but all the ServletContextListeners should
> > complete before the WebappClassLoader starts shedding its loaded classes.
> >
> > Are you explicitly shutting-down the ClientCnxn thread in a SCL's
> > destroy() method? If not, you need to do that.
> >
>
> Sorry,I can't get any more of the stack trace.
>
> We wrapped zookeepr client as a spring bean and invoked method "close" of
> zookeeper in "destory-method" of bean,in that method "close",zookeeper Send
> Thread was closed.
> When tomcat was shut down, Spring closed it's container and bean was
> detroyed, then "destroy-method" of bean was invoked.
> I'am confusing why is Send Thread of Zookeeper seemed to exit slower than
> the WebappClassLoader shedding its loaded classes.
>
> ps: details of zookeeper closing
> org.apache.zookeeper.Zookeeper
> public synchronized void close() throws InterruptedException {
> if (!cnxn.getState().isAlive()) {
> if (LOG.isDebugEnabled()) {
> LOG.debug("Close called on already closed client");
> }
> return;
> }
> if (LOG.isDebugEnabled()) {
> LOG.debug("Closing session: 0x" +
> Long.toHexString(getSessionId()));
> }
> try {
> cnxn.close();
> } catch (IOException e) {
> if (LOG.isDebugEnabled()) {
> LOG.debug("Ignoring unexpected exception during close", e);
> }
> }
> LOG.info("Session: 0x" + Long.toHexString(getSessionId()) + "
> closed");
> }
> ----------------------------------------------------------------------------------------------------------------------
> org.apache.zookeeper.ClientCnxn
> public void close() throws IOException {
> if (LOG.isDebugEnabled()) {
> LOG.debug("Closing client for session: 0x"
> + Long.toHexString(getSessionId()));
> }
> try {
> RequestHeader h = new RequestHeader();
> h.setType(ZooDefs.OpCode.closeSession);
> submitRequest(h, null, null, null);
> } catch (InterruptedException e) {
> // ignore, close the send/event threads
> } finally {
> disconnect();
> }
> }
>
>
> public void disconnect() {
> if (LOG.isDebugEnabled()) {
> LOG.debug("Disconnecting client for session: 0x"
> + Long.toHexString(getSessionId()));
> }
> sendThread.close();
> eventThread.queueEventOfDeath();
> }
> -------------------------------------------------------------------------------------------------
>
>
> org.apache.zookeeper.ClientCnxn.SendThread
> void close() {
> state = States.CLOSED;
> clientCnxnSocket.wakeupCnxn();
> }
>
>
> @Override
> public void run() {
> clientCnxnSocket.introduce(this,sessionId);
> clientCnxnSocket.updateNow();
> clientCnxnSocket.updateLastSendAndHeard();
> int to;
> long lastPingRwServer = System.currentTimeMillis();
> while (state.isAlive()) {
> try {
> if (!clientCnxnSocket.isConnected()) {
> if(!isFirstConnect){
> try {
> Thread.sleep(r.nextInt(1000));
> } catch (InterruptedException e) {
> LOG.warn("Unexpected exception", e);
> }
> }
> // don't re-establish connection if we are closing
> if (closing || !state.isAlive()) {
> break;
> }
> startConnect();
> clientCnxnSocket.updateLastSendAndHeard();
> }
> if (state.isConnected()) {
> // determine whether we need to send an AuthFailed
> event.
> if (zooKeeperSaslClient != null) {
> boolean sendAuthEvent = false;
> if (zooKeeperSaslClient.getSaslState() ==
> ZooKeeperSaslClient.SaslState.INITIAL) {
> try {
>
> zooKeeperSaslClient.initialize(ClientCnxn.this);
> } catch (SaslException e) {
> LOG.error("SASL authentication with
> Zookeeper Quorum member failed: " + e);
> state = States.AUTH_FAILED;
> sendAuthEvent = true;
> }
> }
> KeeperState authState =
> zooKeeperSaslClient.getKeeperState();
> if (authState != null) {
> if (authState == KeeperState.AuthFailed) {
> // An authentication error occurred
> during authentication with the Zookeeper Server.
> state = States.AUTH_FAILED;
> sendAuthEvent = true;
> } else {
> if (authState ==
> KeeperState.SaslAuthenticated) {
> sendAuthEvent = true;
> }
> }
> }
> if (sendAuthEvent == true) {
> eventThread.queueEvent(new WatchedEvent(
> Watcher.Event.EventType.None,
> authState,null));
> }
> }
> to = readTimeout - clientCnxnSocket.getIdleRecv();
> } else {
> to = connectTimeout - clientCnxnSocket.getIdleRecv();
> }
>
> if (to <= 0) {
> throw new SessionTimeoutException(
> "Client session timed out, have not heard
> from server in "
> + clientCnxnSocket.getIdleRecv() +
> "ms"
> + " for sessionid 0x"
> + Long.toHexString(sessionId));
> }
> if (state.isConnected()) {
> int timeToNextPing = readTimeout / 2
> - clientCnxnSocket.getIdleSend();
> if (timeToNextPing <= 0) {
> sendPing();
> clientCnxnSocket.updateLastSend();
> } else {
> if (timeToNextPing < to) {
> to = timeToNextPing;
> }
> }
> }
> // If we are in read-only mode, seek for read/write server
> if (state == States.CONNECTEDREADONLY) {
> long now = System.currentTimeMillis();
> int idlePingRwServer = (int) (now - lastPingRwServer);
> if (idlePingRwServer >= pingRwTimeout) {
> lastPingRwServer = now;
> idlePingRwServer = 0;
> pingRwTimeout =
> Math.min(2*pingRwTimeout, maxPingRwTimeout);
> pingRwServer();
> }
> to = Math.min(to, pingRwTimeout - idlePingRwServer);
> }
> clientCnxnSocket.doTransport(to, pendingQueue,
> outgoingQueue, ClientCnxn.this);
> } catch (Throwable e) {
> if (closing) {
> if (LOG.isDebugEnabled()) {
> // closing so this is expected
> LOG.debug("An exception was thrown while closing
> send thread for session 0x"
> + Long.toHexString(getSessionId())
> + " : " + e.getMessage());
> }
> break;
> } else {
> // this is ugly, you have a better way speak up
> if (e instanceof SessionExpiredException) {
> LOG.info(e.getMessage() + ", closing socket
> connection");
> } else if (e instanceof SessionTimeoutException) {
> LOG.info(e.getMessage() + RETRY_CONN_MSG);
> } else if (e instanceof EndOfStreamException) {
> LOG.info(e.getMessage() + RETRY_CONN_MSG);
> } else if (e instanceof RWServerFoundException) {
> LOG.info(e.getMessage());
> } else {
> LOG.warn(
> "Session 0x"
> + Long.toHexString(getSessionId())
> + " for server "
> +
> clientCnxnSocket.getRemoteSocketAddress()
> + ", unexpected error"
> + RETRY_CONN_MSG, e);
> }
> cleanup();
> if (state.isAlive()) {
> eventThread.queueEvent(new WatchedEvent(
> Event.EventType.None,
> Event.KeeperState.Disconnected,
> null));
> }
> clientCnxnSocket.updateNow();
> clientCnxnSocket.updateLastSendAndHeard();
> }
> }
> }
> cleanup();
> clientCnxnSocket.close();
> if (state.isAlive()) {
> eventThread.queueEvent(new WatchedEvent(Event.EventType.None,
> Event.KeeperState.Disconnected, null));
> }
> ZooTrace.logTraceMessage(LOG, ZooTrace.getTextTraceLevel(),
> "SendThread exitedloop.");//at this
> line, error occurs.
> }
> --------------------------------------------------------------------------------------------------------------
>
> Regards,
> Bob
>
>
>
>
>
>
