[logback-user] JMX on a WebSphere clustered environment

Roy Cronise sweep at ccyor.com
Thu May 31 01:36:43 CEST 2012

Chris, Since you are using websphere you could use the Dynamic cache
to push the logging levels around to all the servers in the cluster.

You would need to implement a LoggerContextListener to update the
Dynamic cache when a log level changes.  Something like this:

public class LogbackContextListener implements LoggerContextListener {
     private static final String LOG_ID = "LBLOG:";
     public void onLevelChange(Logger logger, Level level)  {
          if (DynamicCacheAccessor.isCachingEnabled()) {
               DistributedMap map = DynamicCacheAccessor.getDistributedMap();
               map.put(LOG_ID + logger.getName(),
level,1,60,60,EntryInfo.SHARED_PUSH, null);  //Update dynamic cache
and push to other servers

and a Dynamic Cache ChangeListener, something like this:

public class LogbackCacheChangeListener implements ChangeListener {
   public void cacheEntryChanged(ChangeEvent changeEvent) {
        if (ChangeEvent.LOCAL != changeEvent.getSourceOfChance()) {
//Level not changed on this server then nothing to do
{  //Log level changed in cache?
                 LoggerContext lc = (LoggerContext)
                 String loggerName =
                  Logger logger = lc.getLogger(loggerName);
//set logger level on server to what was pushed in cache.

Sorry for any typos...


On Wed, May 30, 2012 at 5:00 PM,  <Christopher.White at bbh.com> wrote:
> Thank you for the reply.
> When you say "sharing the configuration file by all instances", do you mean
> having both servers point to the same logback.xml config file? If this is
> what you meant, I'm not exactly sure how I could use this to my advantage,
> perhaps you could elaborate more on this suggestion.
> My ultimate goal is to give the end user of my web application (with an
> admin role) the ability to change the logging level of any logger at runtime
> (and have this change applied to both servers in my cluster).
> Is it possible, in java code, to modify the logging level of a logger, and
> then save the modifications back to the original logback.xml configuration
> file? If this is possible, then I can see how your suggestion could help
> me...
>         1. End user submits request for change in logging level on some
> logger (which is received by server 1)
>         2. Application code uses Logback API to make the desired changes at
> runtime
>         3. Application code uses Logback API to save the current runtiime
> configuration back to logback.xml (still on server 1)
>         4. Server 2 is also looking at the same logback.xml file (with
> auto-scan enabled). Once the file is updated, the auto-scan will trigger on
> server 2, and the logging level changes will then be applied to server 2 as
> well.
> Before I go too far with the above approach, I just have a follow-up
> question to using JMX. Here is the code snippet that I am using to get the
> mbean proxy instance:
> mbean = javax.management.JMX.newMBeanProxy(mbs, objectName,
> JMXConfiguratorMBean.class, true);
> The last parameter is set to "true", which is supposed to enable
> broadcasting of the message (to other Mbeans on the MbeanServer I assume) if
> the Mbean happens to implement NotificationBroadcaster. Based upon some
> reading on other forums, I think this is how JMX can be used to propagate
> the message to all servers in the cluster.
> Here is the excerpt from the Javadoc:
> This method behaves the same as newMBeanProxy(MBeanServerConnection,
> ObjectName, Class), but additionally, if notificationBroadcaster is true,
> then the MBean is assumed to be a NotificationBroadcaster or
> NotificationEmitter and the returned proxy will implement
> NotificationEmitter as well as interfaceClass. A call to
> NotificationBroadcaster.addNotificationListener(javax.management.NotificationListener,
> javax.management.NotificationFilter, java.lang.Object) on the proxy will
> result in a call to
> MBeanServerConnection.addNotificationListener(ObjectName,
> NotificationListener, NotificationFilter, Object), and likewise for the
> other methods of NotificationBroadcaster and NotificationEmitter.
> Type Parameters:
> T - allows the compiler to know that if the interfaceClass parameter is
> MyMBean.class, for example, then the return type is MyMBean.
> Parameters:
> connection - the MBean server to forward to.
> objectName - the name of the MBean within connection to forward to.
> interfaceClass - the management interface that the MBean exports, which will
> also be implemented by the returned proxy.
> notificationBroadcaster - make the returned proxy implement
> NotificationEmitter by forwarding its methods via connection.
> Returns:
> the new proxy instance.
> Does the Logback JMX Mbean implement NotificationEmitter or
> NotificationBroadcaster? If not, do you think that if it did implement one
> of these interfaces, that my issue would be resolved?
> Thanks,
> -Chris
> From:        ceki <ceki at qos.ch>
> To:        logback users list <logback-user at qos.ch>
> Date:        05/30/2012 03:39 PM
> Subject:        Re: [logback-user] JMX on a WebSphere clustered environment
> Sent by:        logback-user-bounces at qos.ch
> ________________________________
> Chris,
> Would sharing the configuration file by all instances be a possibility?
> If yes, you could probably get by with the auto-scan feature.
> --
> Ceki
> http://twitter.com/#!/ceki
> On 30.05.2012 20:50, Christopher.White at bbh.com wrote:
>> Hi,
>> I'm trying to use Logback JMX in my application to allow me to change
>> the configuration at runtime.
>> I've created client code that can retrieve the JMX bean, and am able to
>> invoke the JMX bean to get/set logging levels.
>> This works just fine on one single server. However, my application is
>> deployed on a cluster of two servers. When invoking the JMXConfigurator,
>> it only modifies the logging configuration on the particular server that
>> I happened to connect to for that http request, but does not modify the
>> configuration on the other clustered server.
>> Am I missing something, or is there no way to have one JMX call update
>> the logback configuration on all clustered servers? Am I perhaps
>> retrieving the JMX bean incorrectly for a clustered environment? Any
>> help would be greatly appreciated.
>> Here is the client code I am using to access the JMX bean:
>> String contextName = "myContextName";
>> String objectNameStr =
>> ch.qos.logback.classic.jmx.MBeanUtil.getObjectNameFor(contextName,
>> JMXConfigurator.class);
>> javax.management.ObjectName objectName = new
>> javax.management.ObjectName(objectNameStr);
>> javax.management.MBeanServer mbs =
>> java.lang.management.ManagementFactory.getPlatformMBeanServer();
>> mbean = javax.management.JMX.newMBeanProxy(mbs, objectName,
>> JMXConfiguratorMBean.class, true);
>> mbean.setLoggerLevel("myLogger", "debug");
>> Thanks,
>> -Chris
> _______________________________________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://mailman.qos.ch/mailman/listinfo/logback-user
> *************************** IMPORTANT NOTE*****************************--
> The opinions expressed in this message and/or any attachments are those of
> the author and not necessarily those of Brown Brothers Harriman & Co., its
> subsidiaries and affiliates ("BBH"). There is no guarantee that this message
> is either private or confidential, and it may have been altered by
> unauthorized sources without your or our knowledge. Nothing in the message
> is capable or intended to create any legally binding obligations on either
> party and it is not intended to provide legal advice. BBH accepts no
> responsibility for loss or damage from its use, including damage from virus.
> ********************************************************************************
> _______________________________________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://mailman.qos.ch/mailman/listinfo/logback-user

More information about the Logback-user mailing list