Restart a pool MBean

[k2c]

Hi to all,

I am using jboss 2.4.9 and i am trying to solve the problem with DB pool when a DB connection is lost and after a while is up again. In this case the beans which use this pool will give an exception error like
'[11:45:52,125,testEJB] testDb 1872488 *** Exception in testDb()! Error: java.lang.RuntimeException: No ManagedConnections Available!'

My solution might be restarting the Mbean which manages the pool i am using when the DB is up again, instead of restarting jboss all over again. Is this possible?

I have tried to do this in the jmx-console but with no sucess. I tried to execute the stop method and it returned with sucess. Then i tried to execute the start method and it gave me the following error:

'The MBean [DefaultDomain:service=XADataSource,name=CORE_DB] throws an MBeanException when calling [start]:
javax.naming.NameAlreadyBoundException: java:/CORE_DB already exists in the NonSerializableFactory map '


And in my server.log:

'[12:18:44,704,testEJB] testDb *** testEJB.testDb - Exception! Error: javax.naming.NameNotFoundException: CORE_DB not bound'

So the pool Mbean is not working anymore. What can i do to solve this situation? How can i bound again the MBean?

Is this a good solution to solve this kind of problems with the pools ?

Thanks to all in advance.

P.S: I have seen in several posts that the best solution is to upgrade to a 3.x or 4 jboss version, but in my case i must use the 2.4.9 version.

[juha]

Try undeploying the components that depend on the datasource (the EJBs), then bounce the datasource and redeploy the applications. Maybe that yields a better result.

[k2c]

Hi juha!

Thanks for your quick reply! :)

I am a newbie to jboss and i have a doubt. What do you mean by 'bounce the datasource' ? What are the actions to follow to do that action?

I understand that deploy and undeploy is place and remove the ejb from the deploy directory.

Thanks once more for your help.

[juha]

Hmm, right. 2.x doesn't have redeployable services, only EJBs. Undeploy EJB, stop/start datasource, deploy EJB.

[k2c]

Ok this is my output from the server.log file
when i do those actions:

'
[12:58:49,715,CORE_DB] Stopping
[12:58:49,716,CORE_DB] XA Connection pool CORE_DB removed from JNDI
[12:58:49,716,XAPoolDataSource] Closing DataSource
[12:58:49,716,XAPoolDataSource] Binding to JNDI name null
[12:58:49,716,ObjectPool] Removing pool: CORE_DB
[12:58:49,719,CORE_DB] XA Connection pool CORE_DB shut down
[12:58:49,719,CORE_DB] Stopped
[12:58:57,185,Connection] PING
[12:58:57,185,Connection] PONG, serverIL=org.jboss.mq.il.jvm.JVMServerIL@1fe451
[12:59:03,094,Connection] PING
[12:59:03,094,Connection] PONG, serverIL=org.jboss.mq.il.jvm.JVMServerIL@1fe451
[12:59:03,271,CORE_DB] Starting
[12:59:03,272,CORE_DB] setGCInterval(30000)
[12:59:03,272,CORE_DB] setGCMinIdleTime(60000)
[12:59:03,272,CORE_DB] setIdleTimeout(60000)
[12:59:03,272,CORE_DB] setTimestampUsed(true)
[12:59:03,272,XAConnectionFactory] Starting
[12:59:03,331,ObjectPool] Adding pool: CORE_DB, GC enabled: true
[12:59:03,339,CORE_DB] Stopped
javax.naming.NameAlreadyBoundException: java:/CORE_DB already exists in the NonSerializableFactory map
at org.jboss.naming.NonSerializableFactory.bind(NonSerializableFactory.java:88)
at org.jboss.jdbc.XADataSourceLoader.bind(XADataSourceLoader.java:486)
at org.jboss.jdbc.XADataSourceLoader.startService(XADataSourceLoader.java:439)
at org.jboss.util.ServiceMBeanSupport.start(ServiceMBeanSupport.java:103)
at java.lang.reflect.Method.invoke(Native Method)
at com.sun.management.jmx.MBeanServerImpl.invoke(MBeanServerImpl.java:1628)
at com.sun.management.jmx.MBeanServerImpl.invoke(MBeanServerImpl.java:1523)
at com.sun.jdmk.comm.HtmlInvokePage.buildPage(HtmlInvokePage.java:240)
at com.sun.jdmk.comm.HtmlRequestHandler.processGetRequest(HtmlRequestHandler.java:325)
at com.sun.jdmk.comm.HtmlRequestHandler.processRequest(HtmlRequestHandler.java:152)
at com.sun.jdmk.comm.HtmlRequestHandler.doRun(HtmlRequestHandler.java:79)
at com.sun.jdmk.comm.ClientHandler.run(ClientHandler.java:84)
at java.lang.Thread.run(Thread.java:479)
'
Probably we should unregister the Name CORE_DB from the NonSerializableFactory....

Any help ?

Thanks

[juha]

javax.naming.Context.rebind()

don't know if it is exposed as an MBean anywhere (naming service, or JNDI View), if not you'll have to implement your own MBean that does.

[k2c]

Hi juha!

Do you know some source of information where can i learn how to implement the method rebind() in a MBean ?

Another aproach .... What if we use RMI to start and stop the MBean? Would that be the same as manually stopping and starting the Mbean ?

Thanks

[juha]

Any tutorial that explains how to use JNDI should do. RMI works the same.

[k2c]

Hi to all!

I have tried the rebind and unbind commands with no success. Below are the steps i have followed:

1. Went to the JNDIView in the console and it showed me an entry to the mbean CORE_DB like this:
CORE_DB (class: org.jboss.pool.jdbc.xa.XAPoolDataSource)

2. Then i made a stop in the CORE_DB service service=XADataSource,name=CORE_DB

3. went again to the JNDIView service and the CORE_DB entry no longer exists.

4. Then tried to start the CORE_DB mbean again and the same error appeared like the one i have showed before.
javax.naming.NameAlreadyBoundException: java:/CORE_DB already exists in the NonSerializableFactory map

5. The next step was to implement an mbean which might do a rebind.

This is the code of the rebind method:
public void rebindDBMb() {

try {
System.setProperty("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory");
System.setProperty("java.naming.provider.url", "localhost:8082");
System.out.println("[stopDBMb] : get Context");
Context ctx = new InitialContext();

System.out.println("[stopDBMb] : lookup");
XAPoolDataSource ref = (XAPoolDataSource) ctx.lookup("java:/CORE_DB");
System.out.println("[stopDBMb] : rebind");
ctx.rebind("java:/CORE_DB",ref);

} catch (Exception e) {
System.out.println("ERROR in MBean MyMonitor: stopDBMb");
}
}

But it did not work

This is the result from the server.log which shows the sequence i have made:

[17:26:36,799,CORE_DB] Stopping
[17:26:36,800,CORE_DB] XA Connection pool CORE_DB removed from JNDI
[17:26:36,800,XAPoolDataSource] Closing DataSource
[17:26:36,800,XAPoolDataSource] Binding to JNDI name null
[17:26:36,801,ObjectPool] Removing pool: CORE_DB
[17:26:36,805,CORE_DB] XA Connection pool CORE_DB shut down
[17:26:36,805,CORE_DB] Stopped
[17:26:55,798,CORE_DB] Starting
[17:26:55,799,CORE_DB] setGCInterval(30000)
[17:26:55,799,CORE_DB] setGCMinIdleTime(60000)
[17:26:55,799,CORE_DB] setIdleTimeout(60000)
[17:26:55,799,CORE_DB] setTimestampUsed(true)
[17:26:55,800,XAConnectionFactory] Starting
[17:26:55,867,ObjectPool] Adding pool: CORE_DB, GC enabled: true
[17:26:55,875,CORE_DB] Stopped
javax.naming.NameAlreadyBoundException: java:/CORE_DB already exists in the NonSerializableFactory map
at org.jboss.naming.NonSerializableFactory.bind(NonSerializableFactory.java:88)
at org.jboss.jdbc.XADataSourceLoader.bind(XADataSourceLoader.java:486)
at org.jboss.jdbc.XADataSourceLoader.startService(XADataSourceLoader.java:439)
at org.jboss.util.ServiceMBeanSupport.start(ServiceMBeanSupport.java:103)
at java.lang.reflect.Method.invoke(Native Method)
at com.sun.management.jmx.MBeanServerImpl.invoke(MBeanServerImpl.java:1628)
at com.sun.management.jmx.MBeanServerImpl.invoke(MBeanServerImpl.java:1523)
at com.sun.jdmk.comm.HtmlInvokePage.buildPage(HtmlInvokePage.java:240)
at com.sun.jdmk.comm.HtmlRequestHandler.processGetRequest(HtmlRequestHandler.java:325)
at com.sun.jdmk.comm.HtmlRequestHandler.processRequest(HtmlRequestHandler.java:152)
at com.sun.jdmk.comm.HtmlRequestHandler.doRun(HtmlRequestHandler.java:79)
at com.sun.jdmk.comm.ClientHandler.run(ClientHandler.java:84)
at java.lang.Thread.run(Thread.java:479)

[17:27:03,714,STDOUT] [stopDBMb] : get Context
[17:27:03,714,STDOUT] [stopDBMb] : lookup
[17:27:03,715,STDOUT] ERROR in MBean MyMonitor: stopDBMb

So as you see an error has occured in my mbean after the lookup command.

6. Next i try to view the JNDIView service and the console just hangs. It does not shows nothing and the browser keeps waiting for information to arrive. Probably i have messed with the Naming factory properties. But what am i doing wrong?

Does the system properties are not right?

Thanks to all in advance.

[diegolealbr]

I had to use

Hashtable ht = new Hashtable();
ht.put(RMIConnectorServer.JNDI_REBIND_ATTRIBUTE, "true");
JMXConnectorServer jmxCS = JMXConnectorServerFactory.newJMXConnectorServer(url, ht, mbs);


where mbs is my MBeanServer