Using weblogic.cluster.singleton.SingletonService

We have written a Singleton class implementing this interface
weblogic.cluster.singleton.SingletonService
http://otndnld.oracle.co.jp/document/products/wls/docs100/javadocs/weblogic/cluster/singleton/SingletonService.html
and have seen on one occasion a thread dump which shows 2 instances of the class actively running at the same time
the docs say
This interface defines a stateless lightweight singeton service that has the following contract:
Activate is invoked on one and only one server in a cluster
The question is whether this implies there is only one instance within that server at any time, or can multiple exist?

No, only one instance will be started at one single managed server in the cluster.

Similar Messages

Continous HTTP access error logged when using Weblogic Cluster

I am not sure if this is the right forum for this discussion, but here we go anyways.
We have created a Weblogic Cluster with one Administration Server and up to 12 Managed Servers. Our Weblogic version is 9.2.
SSL has been enabled for all Servers and the HTTP Listen Ports are all turned off. The cluster and all applications are working fine and communicating over HTTP as expected, however the logs grow 3MB+ per hour due to an error that repeatedly logged. This error appears to be an attempt by an internal Weblogic process to access some resource over HTTP.
Here are the various messages received in the logs. There are 3 messages logged per error occurred.
This first log message is from the domain log (I replaced the hostname/IP info with <PEER>):
####<Aug 11, 2008 12:08:46 PM GMT+00:00> <Warning> <Security> <PEER> <ManagedServer7> <[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <> <1218456526962> <BEA-090475> <Plaintext data for protocol HTTP was received from peer <PEER> instead of an SSL handshake.>
This second log message is from the ".out" log from the Administration Server:
####<Aug 11, 2008 12:08:58 PM GMT+00:00> <Info> <ServletContext-/bea_wls_internal> <PEER> <AdminServer> <[ACTIVE] ExecuteThread: '1' for queue: 'weblogic.kernel.Default (self-tuning)'> <<anonymous>> <> <> <1218456538658> <000000> <HTTPClntLogin: Login rejected with code: 'Failed', reason: java.net.ProtocolException: HTTP tunneling is disabled
at weblogic.rjvm.http.HTTPServerJVMConnection.acceptJVMConnection(HTTPServerJVMConnection.java:88)
at weblogic.rjvm.http.TunnelLoginServlet.service(TunnelLoginServlet.java:80)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3231)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2002)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1908)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1362)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:181)
This last message is from the access.log for the Admin Server:
<PEER> - - [11/Aug/2008:12:08:58 +0000] "GET /bea_wls_internal/HTTPClntLogin/a.tun?wl-login=https+dummy+WLREQS+9.2.2.0+dummy+%0A&rand=8038349418070109915&AS=2048&HL=19 HTTP/1.1" 200 1337
I have searched all over trying to find a solution but with no luck thus far. I have seen some posts about turning on HTTPTunneling and this does seem to prevent the error from occurring, but this is not a solution for us.
I could really use some help in understanding whats going on and trying to resolve this issue. Our client will make a big deal out of this and will want a solution. Any help would be greatly appreciated.
Message was edited by:
user651444

Hi,
We had this problem with WebLogic Platform 9.2 MP2, running on Solaris. The patch CR344429 worked fine. The corresponding patch for 9.2 MP3 is CR370091. You can get these patches through Oracle Support.
A couple of points:
1. We did not have to set StartScriptEnabled=true for the patch to work. We use the SSL Niode manager.
2. Using the t3: protocol (-Dweblogic.management.server=t3://<admin server listen address>:<admin server listen port) does stop these exceptions, but causes these warning messages to appear in the administration server log file:
<Warning> <[STANDBY] ExecuteThread: '5' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <> <...> <BEA-002637> <Failed to register a disconnect listener because of weblogic.rmi.extensions.DisconnectMonitorUnavailableException: Could not register a DisconnectListener for [weblogic.rmi.internal.BasicRemoteRef ......>
<Warning> <[STANDBY] ExecuteThread: '5' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <> <...> <BEA-002637> <Failed to register a disconnect listener because of weblogic.rmi.extensions.DisconnectMonitorUnavailableException: Could not register a DisconnectListener for [weblogic.rmi.internal.BasicRemoteRef ......>
Hope these comments help.

Singletons in WebLogic cluster

In my clustered EJB application, there are 3 stateless session beans that need to run as singleton services on exactly one node. So I implemented the interface weblogic.cluster.singleton.SingletonService in these beans with the activate and deactivate methods. The beans and all classes of the application are contained in an ear file I deploy to the entire cluster. Then I configured the bean classes as singletons using the WebLogic console administration (cluster details -> singleton service). After I activated this in changes center, I see a ClassNotFoundException with the class name of one of the beans. So I extracted the ear file to the domain/lib directory, restarted the server and tried again to configure the singleton classes. This time the activation failed because of another reason (HibernateException). I think the reason is, this operation is done in the context of my administration server, not of the cluster server. It seems this doesn't work.
Is it possible to deploy the EJB application with the beans as singletons?
I already found another solution: to set the maximum number of beans in weblogic-ejb-jar.xml, field max-beans-in-free-pool, to 1. This solution is a little bit dirty, after starting the servers, I get an exception on all other nodes complaining that it is not possible to deploy this bean. What I don't know: how would it be handled, if the node with the deployed beans is shut down? Are the beans deployed on the other nodes automatically (as I expect for singleton services) or keep undeployed?
Thanks in advance!
BTW: I'm using WebLogic 10.3 on Windows.

Maybe this will help: http://middlewaremagic.com/weblogic/?p=5799
Also to make Hibernate run on WebLogic you have perform certain steps, there is
problem with the antlr version that ships with Hibernate as another version of
antlr is already loaded in the system classpath of WebLogic.
Some instructions are presented here: http://middlewaremagic.com/weblogic/?p=5861

Singleton Classes in Weblogic cluster

Hi
Our application is having singleton classes which we refresh programatically ;though very rarely. We need to move our application into a weblogic cluster. The sigleton class refresh also needs to reflect across the servers :
I could see the SingletonService API here http://download.oracle.com/docs/cd/E12839_01/apirefs.1111/e13941/weblogic/cluster/singleton/SingletonService.html. This contain an activate() and deactivate() .Can we call this activate() method to refresh the singleton object whenever there is a refresh required ? Can we define multiple singleton service classes in the cluster ?
Thanks
Suneesh

I've same issue with singleton service...
1) I’ve created a cluster MyCluster with Man1 & Man2 managed instances.
2) I’ve created singleton.jar out of TestCache.java, which is a singleton cache and have deployed it to the MyCluster.
3) I’ve created man.jar out of StartupClassMan.java, which is a startup class and have deployed it to the MyCluster. And I’ve specified this as startup class for the whole MyCluster.
4) For MyCluster, I’ve specified com.mytest.TestCache.class as singleton service with preferred server as Man1 with migratable to Man2.
5) I run Man1, startup class StartupClassMan is invoked and it gets reference to TestCache, populates the cache & prints size as 1.
6) Now when I run Man2, startup class StartupClassMan is invoked and it get references to TestCache & populates the cache & prints size as 1 only.
For some reason, TestCache is not considered as true singleton. If it is true singleton, running Man2 should have printed size 2 as Man1 has already put one entry into the cache.
And I also don't see activate & deactivate method being called when I run Man1 or Man2 servers. Any help on this is really appreciated.
package com.mytest;
import java.util.Map;
import java.util.HashMap;
public class TestCache implements weblogic.cluster.singleton.SingletonService
private static TestCache testCache = new TestCache();
private Map<String, String> mapCache = new HashMap<String, String>();
private TestCache() {}
public void activate() {
System.out.println("TestCache activate called");
public void deactivate() {
System.out.println("TestCache deactivate called");
public static TestCache getTestCache() {
return testCache;
public void put(String key, String value) {
mapCache.put(key, value);
public String get(String key) {
return mapCache.get(key);
public void remove(String key) {
mapCache.remove(key);
public int size() {
return mapCache.size();
package com.mytest;
public class StartupClassMan
public static void main(String args[]) {
System.out.println("StartupClassMan loaded");
TestCache testCache = TestCache.getTestCache();
testCache.put("Man1","Man1");
System.out.println("size: "+testCache.size());
}

Timesten database driver is not supported in Weblogic cluster mode??

Does anybody encounter this situation??
I have 2 managed server in a Weblogic cluster domain and there is DataSource for them.
In each managed server, I setup Timesten client correctly to connect to Timesten Oracle DB cache server.
But when we start each of managed server, I will get exception:
####<Nov 22, 2010 6:03:24 PM CST> <Critical> <WebLogicServer> <Machine1> <Main Thread> <<WLS Kernel>> <1290420204498> <BEA-000386> <Server subsystem failed. Reason: java.lang.AssertionError:
java.lang.AssertionError: Unsupported database driver
at weblogic.cluster.singleton.QueryHelperImpl.getTimeFunction(QueryHelperImpl.java:88)
at weblogic.cluster.singleton.QueryHelper.getLeaseOwnerQuery(QueryHelper.java:110)
at weblogic.cluster.singleton.DatabaseLeasingBasis.pingDB(DatabaseLeasingBasis.java:411)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:465)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:507)
at weblogic.cluster.singleton.DatabaseLeasingBasis.findOwner(DatabaseLeasingBasis.java:305)
at weblogic.cluster.singleton.LeaseManager.findOwner(LeaseManager.java:218)
at weblogic.cluster.singleton.MigratableServerService.findSingletonMaster(MigratableServerService.java:201)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.syncStateFromActiveStateManager(ReplicatedSingletonServicesStateManager.java:618)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.<init>(ReplicatedSingletonServicesStateManager.java:168)
at weblogic.cluster.singleton.SingletonMonitor.<init>(SingletonMonitor.java:97)
at weblogic.cluster.singleton.SingletonMaster.<init>(SingletonMaster.java:44)
at weblogic.cluster.singleton.MigratableServerService.initialize(MigratableServerService.java:142)
at weblogic.cluster.singleton.MigratableServerService.start(MigratableServerService.java:436)
at weblogic.t3.srvr.SubsystemRequest.run(SubsystemRequest.java:64)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
But if I create a standalone domain, still use the same datasource(still this timesten server), weblogic server can start successfully.
BR,
Peng
Edited by: user8028210 on Nov 25, 2010 1:18 AM
Edited by: user8028210 on Nov 25, 2010 1:19 AM

Does anybody encounter this situation??
I have 2 managed server in a Weblogic cluster domain and there is DataSource for them.
In each managed server, I setup Timesten client correctly to connect to Timesten Oracle DB cache server.
But when we start each of managed server, I will get exception:
####<Nov 22, 2010 6:03:24 PM CST> <Critical> <WebLogicServer> <Machine1> <Main Thread> <<WLS Kernel>> <1290420204498> <BEA-000386> <Server subsystem failed. Reason: java.lang.AssertionError:
java.lang.AssertionError: Unsupported database driver
at weblogic.cluster.singleton.QueryHelperImpl.getTimeFunction(QueryHelperImpl.java:88)
at weblogic.cluster.singleton.QueryHelper.getLeaseOwnerQuery(QueryHelper.java:110)
at weblogic.cluster.singleton.DatabaseLeasingBasis.pingDB(DatabaseLeasingBasis.java:411)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:465)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:507)
at weblogic.cluster.singleton.DatabaseLeasingBasis.findOwner(DatabaseLeasingBasis.java:305)
at weblogic.cluster.singleton.LeaseManager.findOwner(LeaseManager.java:218)
at weblogic.cluster.singleton.MigratableServerService.findSingletonMaster(MigratableServerService.java:201)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.syncStateFromActiveStateManager(ReplicatedSingletonServicesStateManager.java:618)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.<init>(ReplicatedSingletonServicesStateManager.java:168)
at weblogic.cluster.singleton.SingletonMonitor.<init>(SingletonMonitor.java:97)
at weblogic.cluster.singleton.SingletonMaster.<init>(SingletonMaster.java:44)
at weblogic.cluster.singleton.MigratableServerService.initialize(MigratableServerService.java:142)
at weblogic.cluster.singleton.MigratableServerService.start(MigratableServerService.java:436)
at weblogic.t3.srvr.SubsystemRequest.run(SubsystemRequest.java:64)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
But if I create a standalone domain, still use the same datasource(still this timesten server), weblogic server can start successfully.
BR,
Peng
Edited by: user8028210 on Nov 25, 2010 1:18 AM
Edited by: user8028210 on Nov 25, 2010 1:19 AM

Timesten database driver is not supported in Weblogic Cluster mode domain??

Does anybody encounter this situation??
I have 2 managed server in a Weblogic cluster domain and there is DataSource for them.
In each managed server, I setup Timesten client correctly to connect to Timesten Oracle DB cache server.
But when we start each of managed server, I will get exception:
####<Nov 22, 2010 6:03:24 PM CST> <Critical> <WebLogicServer> <Machine1> <Main Thread> <<WLS Kernel>> <1290420204498> <BEA-000386> <Server subsystem failed. Reason: java.lang.AssertionError:
java.lang.AssertionError: Unsupported database driver
at weblogic.cluster.singleton.QueryHelperImpl.getTimeFunction(QueryHelperImpl.java:88)
at weblogic.cluster.singleton.QueryHelper.getLeaseOwnerQuery(QueryHelper.java:110)
at weblogic.cluster.singleton.DatabaseLeasingBasis.pingDB(DatabaseLeasingBasis.java:411)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:465)
at weblogic.cluster.singleton.DatabaseLeasingBasis.getJDBCConnection(DatabaseLeasingBasis.java:507)
at weblogic.cluster.singleton.DatabaseLeasingBasis.findOwner(DatabaseLeasingBasis.java:305)
at weblogic.cluster.singleton.LeaseManager.findOwner(LeaseManager.java:218)
at weblogic.cluster.singleton.MigratableServerService.findSingletonMaster(MigratableServerService.java:201)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.syncStateFromActiveStateManager(ReplicatedSingletonServicesStateManager.java:618)
at weblogic.cluster.singleton.ReplicatedSingletonServicesStateManager.<init>(ReplicatedSingletonServicesStateManager.java:168)
at weblogic.cluster.singleton.SingletonMonitor.<init>(SingletonMonitor.java:97)
at weblogic.cluster.singleton.SingletonMaster.<init>(SingletonMaster.java:44)
at weblogic.cluster.singleton.MigratableServerService.initialize(MigratableServerService.java:142)
at weblogic.cluster.singleton.MigratableServerService.start(MigratableServerService.java:436)
at weblogic.t3.srvr.SubsystemRequest.run(SubsystemRequest.java:64)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
But if I create a standalone domain, still use the same datasource(still this timesten server), weblogic server can start successfully.
BR,
Peng

Hi,
I have use WebLogic Server Console, tree: Services -> JDBC -> Connection Pools. Then I have choose 'Configure a new JDBC Connection Pool...':
1.) as 'Database Type:' I have select MySQL (version using com.mysql.jdbc.Driver) -> click 'Continue' button;
2.) 'Database Name:' = OSS; 'Host Name' = localhost; 'Port' = 3306; 'Database User Name:' = root; -> click 'Continue' button;
3.) 'Driver Classname:' = com.mysql.jdbc.Driver; 'URL:' = jdbc:mysql://localhost:3306/OSS; 'Database User Name:' = root; 'Properties:' = user=root -> click to 'Test Driver Configuration' button.
After click on test driver button I get message: JDBC driver is not on the CLASSPATH.
But when I check System variables (in Control Panel -> System) I have set up following:
CLASSPATH=.;C:\DB2\java\db2java.zip;C:\DB2\java\db2jcc.jar;C:\DB2\java\sqlj.zip;C:\DB2\java\db2jcc_license_cu.jar;C:\DB2\bin;C:\DB2\java\common.jar;C:\DBS\JDBC\db2\db2.jar;C:\DB2\BIN;c:\mysql.jar
The last value is 'c:\mysql.jar' and that's the mysql jdbc driver located on c:\.
I don't understand why weblogic cannot find it.
Any idea?
Thanks in advance for help,
with best regards,
Julian Legeny

WCI 10gR3 - Weblogic Cluster

Hi,
Does WCI 10gR3 support HTTP Session replication using Weblogic Cluster? Is there any documentation about this? I could not find any.
Thanks,
Andreas

Hi,
Most of the time DB store are used instead of the file store.
I recommend to use DB store only.
with this you have option to use leasing option too.
Regards,
Kal

Singleton class in WebLogic Cluster

Hi,
We have an application set-up in a weblogic cluster.
We have a singleton class in the application.
Since we have two managed servers in the cluster the singleton has two instances, one in each server.
So the basic purpose of use of singleton is lost.
Could anyone please give some alternative implementation.
Regards
Gunajit K

One alternative is to set up some type of centralized store for the information you are trying to share between VMs. I would look at what you are trying to do with the singleton and make some descisions.
Specifically, I would at least look at how much access you will need to the data, how much network traffic it will take to send it to each node in your cluster, and what kind of transactional integrity you require.
A JMS publish/subscribe topic would be a good solution if you are caching some type of data that changes relatively infrequently. You could set this up yourself or check out SpiritSoft's Spirit Cache product (no, I don't work for SpiritSoft).
Or you could simply store the information in some type of database and access it via EJBs or JDBC or whatever you like.
Clearly, the performance of such a store will not be as quick as the in-memory access a Singleton provides inside a single JVM. So be careful about what solution you choose and be sure to optimize its performance as best you can.

How to setup the cluster environment for BPM using weblogic

want to setup the cluster environment for BPM using weblogic....
i have installed the oracle weblogic server 10gr3 and oracle BPM enterprise for weblogic 10gR3
i have used the Admin tools from the "oracle BPM enterprise for weblogic" to setup the configuration and create the weblogic domain servers.
i can launch the process administrator and import the project exp file to domain server.
but what should i do to setup cluster environment using weblogic?
what i want to do is :
setup one admin machine..
setup two product machine..
enable the cluster so the admin machine can monitor the status of the product machine..
thanks a lot ...

The install guide at http://download-llnw.oracle.com/docs/cd/E13154_01/bpm/docs65/config_guide/index.html gives a reasonable amount of info on how to do this.
Personally I have not used the OBPM option to configure WebLogic instead I've used the information in the above install guide to create the weblogic domain in advance of configuring OBPM.
Once you've setup WebLogic configure OBPM using the values I mention in the following thread: How to set the JMX Engine parameter in Process Administation?
Let me know any specific config questions and I'll do my best to answer them for you.
Thanks,
Mike

Web Proxying to a WebLogic Cluster using the HTTPS protocol

Hi all,
I am recently involved into JWS proxying to WebLogic Cluster.
I don't have any technical problems at the moment but "conceptual" problems, that is:
- my jws proxy server should connect to a WebLogic Cluster through a Bea plugin configured wish SSL parameters;
- my jws proxy server should pass the incoming request using a load-balancing algorithm among the two nodes of the cluster, that are actually installed on two different machines;
- the jws proxy server doesn't seem to accept multiple certificates.
My question is: how can I configure my proxy plugin to route the incoming requests to my WebLogic Cluster using the https protocol? As a matter of fact, each certificate should be hostname dependent, and it looks like that the proxy plugin doesn't accept a multiple certificate configuration (and it should actually match the CN entry in the certificates with the actual hostnames of the nodes).
Any hint?
Thx a lot,
Luca

It is supported in 5.2
          - Prasad
          Wei Guan wrote:
          > As I knew of, secure proxying is not supported yet.
          > --
          > Cheers - Wei
          > Bob Kiep <[email protected]> wrote in message
          > news:8bvvc7$7uf$[email protected]..
          > > The NSAPI plugin cannot perform SSL proxying, as documented at the bottom
          > of
          > > this message (taken from
          > > http://www.weblogic.com/docs/admindocs/nsapi.html#background). When
          > > Weblogic is the proxy, can I do SSL? If someone could send me the link to
          > > where is states whether is SSL or not would be very helpful.
          > >
          > > "The plug-in is for an environment where NES serves static pages, and a
          > > Weblogic Server (operating in a different process, possibly on a different
          > > host) is delegated to serve dynamic pages (such as JSPs or pages generated
          > > by HTTP Servlets). The connection between WebLogic Server and the NSAPI
          > > plug-in is clear text http, not SSL. To the end user -- the browser -- the
          > > HTTP requests delegated to WebLogic appear to come from the same source as
          > > the static pages. In other words, WebLogic on the back-end is invisible.
          > > Additionally, the HTTP-tunneling facility of the WebLogic client-server
          > > protocol can operate through the plug-in, providing access to all WebLogic
          > > services (not just dynamic pages). "
          > >
          > >
          Cheers
          - Prasad

EBS datasource in WebLogic cluster using the EBS dbc file

Hi All
Please let me know if someone has successfully created EBS datasource in WebLogic cluster using the EBS dbc file.
I have successfully created the datasource with one managed server but I am getting 'OAuth Mashaling Failure' error while adding the second managed server to this datasource.
Thanks

Thanks Hussein
Here is the complete error:
[wlst] Caused by: weblogic.common.ResourceException: weblogic.common.ResourceException: OAUTH marshaling failure
[wlst] at weblogic.jdbc.common.internal.PooledConnectionEnvFactory.createResource(PooledConnectionEnvFactory.java:133)
[wlst] at weblogic.common.resourcepool.ResourcePoolImpl.makeResources(ResourcePoolImpl.java:1249)
[wlst] at weblogic.common.resourcepool.ResourcePoolImpl.makeResources(ResourcePoolImpl.java:1166)
[wlst] at weblogic.common.resourcepool.ResourcePoolImpl.start(ResourcePoolImpl.java:249)
[wlst] at weblogic.jdbc.common.internal.ConnectionPool.doStart(ConnectionPool.java:1154)
[wlst] at weblogic.jdbc.common.internal.ConnectionPool.start(ConnectionPool.java:154)
[wlst] at weblogic.jdbc.common.internal.ConnectionPoolManager.createAndStartPool(ConnectionPoolManager.java:454)
[wlst] at weblogic.jdbc.common.internal.ConnectionPoolManager.createAndStartPool(ConnectionPoolManager.java:372)
[wlst] at weblogic.jdbc.module.JDBCModule.prepare(JDBCModule.java:255)

NPE using weblogic.httpd.clustering.enable

I'm having some difficulty trying to configure a cluster. If I set the
          property "weblogic.httpd.clustering.enable" to true I will get the attached
          NullPointerException. Where did I do wrong?
          Thanks for help.
          -- Jerry
          Tue Sep 26 14:09:13 PDT 2000:<I> <HTTP> Log rotation is size based
          Unable to initialize server: java.lang.NullPointerException
          fatal initialization exception
          java.lang.NullPointerException
          at weblogic.t3.srvr.HttpServer.start(HttpServer.java:398)
          at weblogic.t3.srvr.T3Srvr.start(T3Srvr.java:1305)
          at weblogic.t3.srvr.T3Srvr.main(T3Srvr.java:827)


          Dimitri Rakitine wrote:
          > I think what it means is that you do not need cluster license (and cluster enabled) to
          > use session persistence, and you do not need to set weblogic.httpd.clustering.enable to
          > use file or jdbc persistence.
          But I do need to use clustering and in order to do that
          I gotta have the weblogic.httpd.clustering.enable set to true among
          all other cluster related properties. What would be the point of using session persistence without
          actually running your servers in a cluster ?
          Right ??
          >
          >
          > Andrzej Porebski <[email protected]> wrote:
          >
          > > We are getting the same exact error (NPE). The reason for this error is null ClusterManager
          > > singleton in weblogic and the only way that thing can be null is if the clustered was not properly configured.
          > > Now, according to weblogic docs, if you use jdbc based session persistence, you should
          > > not have to have the so called "cluster" license for Weblogic but that does not seem
          > > to hold glue. We have configured the server to use the jdbc based session
          > > persistence but we still get the error
          >
          > > Wed Sep 27 14:59:11 EDT 2000:<E> <WebLogicServer> #########################################################
          > > Wed Sep 27 14:59:11 EDT 2000:<E> <WebLogicServer> ## Unable to join cluster: Unable to find a license for clustering
          > > Wed Sep 27 14:59:11 EDT 2000:<E> <WebLogicServer> #########################################################
          >
          > > during startup and then the NPE at the very end.
          >
          > > If any one has solved this problem please let me know.......
          >
          > > Thanks
          >
          > > Andrew
          >
          > > Dimitri Rakitine <[email protected]> wrote:
          > >>I think what Weblogic was trying to say (in a somewhat cryptic way)
          > >>is that you didn't set weblogic.cluster.enable=true property.
          > >>
          > >>Jerry Soung <[email protected]> wrote:
          > >>> I'm having some difficulty trying to configure a cluster. If I set the
          > >>> property "weblogic.httpd.clustering.enable" to true I will get the attached
          > >>> NullPointerException. Where did I do wrong?
          > >>
          > >>> Thanks for help.
          > >>
          > >>> -- Jerry
          > >>
          > >>> Tue Sep 26 14:09:13 PDT 2000:<I> <HTTP> Log rotation is size based
          > >>> Unable to initialize server: java.lang.NullPointerException
          > >>> fatal initialization exception
          > >>> java.lang.NullPointerException
          > >>> at weblogic.t3.srvr.HttpServer.start(HttpServer.java:398)
          > >>> at weblogic.t3.srvr.T3Srvr.start(T3Srvr.java:1305)
          > >>> at weblogic.t3.srvr.T3Srvr.main(T3Srvr.java:827)
          > >>
          > >>Dimitri
          > >>http://dima.dhs.org
          >
          > --
          > Dimitri
          > http://dima.dhs.org

Is Weblogic Cluster supports Application scope Objects?

          Our Application is mainly depends on Application scope objects. On one m/c, it
          is perfect.
          Now, we want to support the failover , load balancing ... (High Availability).
          I know, weblogic cluster supports HttpSessions, EjbObjects ... etc. What about
          Application scope objects.
          we are planning for weblogic server which supports the our requirements.
          If not, what is the solution to make it work by using Weblogic server.
          for eg: I can give what type of application we are developing --- similar to
          textchat.
          our application is real time application.


Even a singleton is not good enough as singletons are good only in the VM they were
          created it. One way is to have a distributed object such as a stateful session bean of
          which only one instance exists. U can create it at startup and store its handle in
          some persistent storage as well as a singleton. This ensures that even if the
          singleton doesnt contain it the refgerence to it can be obtained.
          There will be some problems with this setup as people should not allow it to create
          instances of it . Any such endeavor will lead to a CacheFullException.
          But essentially that seems possible.
          Even the 2.3 Servlet specification mandates that ServletContext and Application level
          object is only valid inside the JVM which created it. HttpSessions are replicated
          SessionContexts are not and are not likely to be in any J2EE application server
          Sameer
          Devi wrote:
          > One more comment from my side,
          > U mentioned "EXCEPT FOR JNDI" , if this is possible, how can we acheive?
          > Can U give brief description ? Take textchat example itself? since, our application
          > is almost have same mechanism. If it is < 1 sec delay means acceptable for this
          > release.
          >
          > Thanks,
          > Devi
          >
          > "Cameron Purdy" <[email protected]> wrote:
          > >Weblogic doesn't support replicated / synchronized app scope objects
          > >across
          > >a cluster except for JNDI, which is probably not a good solution for
          > >what
          > >you are describing.
          > >
          > >If you need a real-time shared fault-tolerant fail-overable high-performance
          > >load-balanced high-scale data store, then let me know when you find one
          > >;-)
          > >.... seriously, there are not a whole lot of good general purpose solutions
          > >in this space. There are some things to look at but they are all expensive:
          > >
          > >Persistent PowerTier on top of Oracle - a caching entity EJB server
          > >Jasmine (or whatever it is called this week) - an object oriented
          > >distributed data store
          > >....
          > >
          > >Peace,
          > >
          > >--
          > >Cameron Purdy
          > >Tangosol Inc.
          > ><< Tangosol Server: How Weblogic applications are customized >>
          > ><< Download now from http://www.tangosol.com/download.jsp >>
          > >
          > >
          > >"Devi" <[email protected]> wrote in message
          > >news:[email protected]...
          > >>
          > >> Our Application is mainly depends on Application scope objects. On
          > >one
          > >m/c, it
          > >> is perfect.
          > >> Now, we want to support the failover , load balancing ... (High
          > >Availability).
          > >>
          > >> I know, weblogic cluster supports HttpSessions, EjbObjects ... etc.
          > > What
          > >about
          > >> Application scope objects.
          > >> we are planning for weblogic server which supports the our requirements.
          > >>
          > >> If not, what is the solution to make it work by using Weblogic server.
          > >> for eg: I can give what type of application we are developing ---
          > >similar to
          > >> textchat.
          > >> our application is real time application.
          > >>
          > >
          > >

File accessing in weblogic cluster 10.3

I have a cluster with 2 instances.
the requirement is like an legacy system putting files in a directory.my ejb timer in weblogic cluster should read the file and process , but the same file should not be read by both instancess in the cluster.if a file is accessed by one instance then other instace should take another file.pls provide the java code and configuration for this.

Hi,
i tried to create a managed server in wls 10.3 and while starting the ms's it is giving a warning that it is not rechable.
Basically i need to migrate a application running in a jboss to wls 10.3.
a sessionbean implemented TimedObject (ie,that i mention as timer),migrate it ro weblogic singleton.
do i need to implement singleton interface in the session bean itself?
like testsessionbean implements TimedObject , weblogic.cluster.SingletonService ,
(it should be part of ejb project and the ear contains the ejb project and web project)
can i put the file accessing funtionality to activate()?
how can i call it from timerejb.
if u give me a sample code with timer ejb accessing singleton it will be helpfull for me
thanks

ACFS recomandations for weblogic cluster

Hi,
Can some one help me to findout material(step by step) for ACFS usage with weblogic clustering.
Originally I started thread here :
Re: ACFS recomandations for weblogic cluster
Thanks in advance for valuable time
Datla

The first question you need to ask yourself is for what purpose do i need this type of filesystem when using a WebLogic Cluster?
The first which comes to mind is the migration of so-called singleton service, such as JMS Servers, persistence stores and JTA.
For example, when a machine fails, we must bring the services, running on the failed machine, up on other machines. The JTA
service plays a critical role in recovery from a failure scenario where transactions are involved. In-flight transactions can hold locks
on underlying resources. If the transaction manager is not available to recover these transactions, resources may hold on to these
locks for a long time. This makes it difficult for an application to function properly. JTA service migration is possible only if the server's
default persistent store (where the JTA logs are kept) is accessible to the server to which the service will migrate.
This where a shared storage mechanism comes into play - to store files which need to be accessible from every server. The concept
of ACFS which is useful in this scenario is the mount model (http://download.oracle.com/docs/cd/E14072_01/server.112/e10500/asmfilesystem.htm#CACJGEAC)
To set-up a mount point you can follow the steps presented here: http://download.oracle.com/docs/cd/E15051_01/wls/docs103/cluster/service_migration.html#wp1049463
This link contains the steps in order to configure JMS migration: http://download.oracle.com/docs/cd/E15051_01/wls/docs103/cluster/service_migration.html#wp1065826
This link contains the steps in order to configure JTA migration: http://download.oracle.com/docs/cd/E15051_01/wls/docs103/cluster/service_migration.html#wp1054024

Using weblogic.cluster.singleton.SingletonService

Similar Messages

Maybe you are looking for