Message Delivery in a Clustered Environment

Hello,
I was wondering if someone could give me a quick explanation/lesson on the following scenario.
I have a two broker cluster (say, SERVERA and SERVERB where SERVERA is the master). Each server has a consumer connected to it, CONA and CONB respectively. I'm throwing evenly distributed producers at the system such that message consumption cannot keep up with production.
CONB is slow due to issues external to the JMS system. After 15 minutes, when I stop the producers, SERVERB has ~3,500 messages in the queue whereas SERVERA has ~450. CONA stops receiving messages when there is still 2750 messages in the queue on SERVERB (SERVERA has 0 left). CONB, which is slow, is left to deal with the remaining messages. Restarting the CONA seems to work and messages being flowing from SERVERB to CONA via SERVERA.
I've tried a consumerFlowLimit of 1000 and 100 but the same thing is happening. I also don't have localDeliveryPreferred set. My goal is to have both CONA and CONB working until all messages in the cluster have been processed. Is there a config setting I can tweak to fix this?
Thanks in advance,
Aaron

Thanks for your response.
I'll answer your questions as best as I can remember but I can't invest any time in recreating the situation. Since this post, we have set localDeliveryPreferred because the amount of inter-broker communication seemed too much. The server with the slow consumer received 6110 messages according to metrics and the fast server received 4950 messages. Each were sent 4080 messages.
What is the MQ broker version and the MQ client
version
(if different from broker) ?They should have both been running 3.5 SP1. However, it is possible that the client was 3.5.
Steps (when/order in starting brokers, producer,
consumers)
to reproduce the problem ?Start cluster brokers.
Start consumers.
Start producers.
After the one consumer stopped receiving messages, I restarted it and messages began flowing again.
Can you provide code examples of the consumers and
producer that reproduces the problem ? This will
also answer the questions like,
Is the destination Queue or Topic ? Queue.
Are the messages produced persistent messages ?Persistent.
Are the consumers using transacted session or what
is acknowledge mode ?DUPS_OK_ACKNOWLEDGE
Aaron

Similar Messages

Jms is not working properly in clustered environment

Hi all,
i am using the application server oc4j 10.1.3.1.0 enterprise edition . my application is standalone application(thick client)
we are using the jndi.properties as follows ...
java.naming.factory.initial=com.evermind.server.rmi.RMIInitialContextFactory
java.naming.provider.url=opmn:ormi://172.16.1.38:6005:group/Security,opmn:ormi://172.16.1.38:6006:deceval_group/Security
java.naming.security.principal=oc4juser
java.naming.security.credentials=oc4juser
oracle.j2ee.rmi.loadBalance=lookup
we have two application servers in cluster topology as u can see above we have used one instance from one application server and one from another.
i have seen that for every instance there one jms server. at runtime it is taking one application servers services
say opmn port 6005 but when the application is connecting to the another application server say opmn 6006
here jms is not working properly when i send message
As we have clustered environment message must be propagated all the applications who use above jndi.properties.
if i keep use only one application server opmn say
java.naming.provider.url=opmn:ormi://172.16.1.38:6005:group/Security
then its is working excellently
please can u provide any solution ASAP
thanks in advance
Manu

Dear Aravindth
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(?) Match zero or one occurrences. Equivalent to {0,1}.
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(.*?) means -> Zero or more times Match any character except newline or another Unicode line terminator + Match zero or more occurrences. Equivalent to {0,}.+Match zero or one occurrences. Equivalent to {0,1}.
Could you please refere the below cite :
http://www.javascriptkit.com/jsref/regexp.shtml
Thanks & Regards
T.R.Harihara SudhaN

Topics and Clustered Environment

Hi,
We have an application that is to be hosted on a clustered environment (2 nodes), for load balancing/fail over. This application consumes JMS messages (from Sonic JMS via Foreign Server).
During development (single node), we have had our application consuming messages from a Topic, meaning that several environments could get copies of the same message. In the clustered environment however, we would only want one of the application pair to consume and process any one message (not both).
The question is - is this possible using Topics? If so, how is it done (using either MDBs or Spring JMS)?
Another option would be to use an intermediate Queue, which consumes messages from a Topic, and the application pair then consume messages from this Queue meaning only one will get any particular message. Is this a good way to go?
If anything is not clear, please let me know and i'll try and clarify.
Thanks for any advice...

Another option would be to use an intermediate Queue, which consumes messages from a Topic, and the application pair then consume messages from this Queue >meaning only one will get any particular message. Is this a good way to go?This looks feasable, only issue would be there is nothing out of the box in wls which gets the message from the remote topic to the queues. You will have to use either a message bridge or a pass thru mdb targeted on a single server to get this done. You might have to then worry about HA if this server goes down. Any how wait for Tom who might be here soon with the expert advice..

MDB behaviour in Clustered environment

Hi, I am a bit confused with regards to how a message delivery will behave in a clustered environment on a app server.
As far as Queue is concerned, I am clear that it will be delevered to one and only one of the MDBs.
But for Topic, how can load balancing effect the Topic subscriptions? Does the Topic then behave in the same manner as the Queue?
I have a J2EE app that is running in clustered env( can be any app server). It has one MDB. I need to send messages to all the application instances at the same time. I am not sure if this solution will work in a clustered environment with JMS load balancing, and I am afraid that this solution will misbehave. Hence the question :)

Delivery to topics is based on subscriptions. One copy of a message is delivered to each subscription. A subscription is identified (in most providers) by the combination of the client id and subscription name. In a clustered environment, each node of the cluster will have a different client id and therefore get a different copy of a message.
Some JMS providers allow for something called group or shared subscriptions where the client id is removed from the subscription identifier and replaced by a group id. This allows two nodes in a cluster to share a subscription to a topic allowing whichever client is up to consume exactly one copy of a message among all nodes in a cluster.
I have to admit that I haven't gotten around to implementing such a feature in my own JMS implementation, but it is on the list.
Dwayne
============
http://dropboxmq.sourceforge.net

Upgrade 10G to 11.1.1.5 in Clustered environment

I successfully ran the upgrade assistant on a single server install. Both RPD and Catalog upgraded with no issues. I scaled out to a 2 node cluster and attempted the upgrade with the assistant again. This time it fails. Here is log entries:
[2011-07-20T15:16:07.861-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Starting to upgrade components.
[2011-07-20T15:16:07.861-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Retain Source Ports: false
[2011-07-20T15:16:07.861-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Stop 10g Components: false
[2011-07-20T15:16:07.861-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Start 11g Components: false
[2011-07-20T15:16:07.876-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Managed server bi_server2 state is: RUNNING
[2011-07-20T15:16:07.876-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Starting to upgrade BIEE.
[2011-07-20T15:16:07.954-04:00] [Framework] [ERROR] [UPGAST-00138] [upgrade.Framework] upgrade exception occurred
[2011-07-20T15:16:07.954-04:00] [Framework] [ERROR] [upgrade.Framework] Cause: An unexpected upgrade exception has occurred. Action: See the secondary error message for additional details.
[2011-07-20T15:16:07.954-04:00] [Framework] [ERROR] [upgrade.Framework] UPGCMP-02712: Expected oracle.biee.admin:oracleInstance=*,type=BIDomain.OracleInstance,group=Service Oracle instance, found 2
[2011-07-20T15:16:07.954-04:00] [Framework] [ERROR] [upgrade.Framework] UPGCMP-02712: Expected oracle.biee.admin:oracleInstance=*,type=BIDomain.OracleInstance,group=Service Oracle instance, found 2
[2011-07-20T15:16:07.954-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Finished upgrading BIEE with status: Failure.
[2011-07-20T15:16:07.954-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] Finished upgrading components.
[2011-07-20T15:16:07.954-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] 0 components upgraded with success.
[2011-07-20T15:16:07.954-04:00] [Framework] [NOTIFICATION] [upgrade.Framework] 1 components upgraded with failure.
Question….can you use upgrade assistant in clustered environment?
Thanks!

You can only use the upgrade assistant to upgrade to a single instance Oracle BI 11g server. Typically this is a sandbox server environment or a VM that can simply be wiped clean after the upgrade. Then move the RPD,WebCat, etc. and AppRoles that get created during the upgrade process to a development server. The UA is looking for a single instance installation environment and that environment should be clean/fresh to avoid confusion and conflicts.
Please award points if helpful.

File Protocol in OSB Clustered Environment

Hi ,
I have a OSB Server in a Clustered Environment ....
Here Admin Server is in Machine1
Managed Server1 is in Machine 2
Managed Server2 is in Machine 3
so both the Managed Servers are put in a Cluster
I have Access to Machine1 Unix Box where the Admin Server is Installed ...I can get the File only in this Location and have to Read the Same from here , So i was planning to Use File Protocol for Polling the Message from Admin Server .Since OSB has option for Selecting only the Managed Server , I would request suggestions how i can Read the Data from this Admin Server by using File Protocol .

have you used "service type" as "Messaging Service" ? that should give you all the options you need

Configuring TLS support in a clustered environment

Hi folks !
I couldn't find a definitive guide to TLS support in a clustered environment... So I'll give it a shout :)
Has anyone managed to configure TLS support in his/her cluster ?
My setup is as follows :
- we have two Ironports, clustered, who are addressed using a common name through a hardware loadbalancer (mxfarm)
- Each ironport is seen as a unique host when sending outbound emails (ironport-1 and ironport-2)
- I have installed a certificate in MACHINE mode on each of them (i.e. one certificate for ironport-1, another for ironport-2)
Now, when I want to enable TLS (in cluster mode), I get the message that a security/key certificate hasn't been installed....
Sooooooooo how should I do it ??
Thanks !!
Frédéric Lens

Hello,
We have four machines in a cluster, using TLS as default for inbound and outbound traffic.
Since we do not use load balancers we have individual certs for each machine. Besides that we have (company signed) certificates for each machine. These are used for systems management (HTTPS). (By the way... the certificate management is a terrible job if you have to maintain four machines with two certs each (and thus two certification paths). Hey Ironport: some major enhancements are possible on this field.....)
Since we use individual certs we have to install them in machine mode. The TLS policies are cluster based and this is configured and functioning without any problems.
I have a few attention points:
The certs that are installed before a machines has joined the cluster are removed on the moment you add this machine to the cluster. This in normally not done very frequently so I think this will not be the problem in this case, but it’s good to know that after joining the cluster you have the initial demo certs active again.
Even if you buy certificates from commercial vendors you must be sure you install the complete certification path. We have Verisign certs and had to install the intermediate certificate to get the chain complete.
You mention you have connected your MGA's to an incoming load balancer and send out mail via the individual hosts. I expect you to utilize three IP addresses for that (one incoming that is assigned to the load balancer and two others for the MGA's outgoing traffic). This means you must have three individual forward and reversed DNS entries. Since the CN of the cert must match the (public) DNS name of your system you should have individual certs for inbound and outbound traffic. The inbound cert (and intermediate certs) must be the same on both machines since these are is presented to the outside world as if they where one and should match the forward DNS name of the load balancer IP address. The outbound certs must be unique for each machine, matching the reversed DNS name of that machine.
I have two points that I'm not sure of, maybe someone else can clear this up:
The SMTP greeting normally contains the public systems hostname. I do not know if you can configure individual SMTP greetings for in and outbound mail and, if this is possible, if the inbound greeting can be the same on two clustered machines. Since you have two machines combined behind a loadbalancer I would expect the to present them selves to the public identically, for the outbound traffic is the individual machine IP address used, I would expect the system to identify it selves by the hostname that is in the PTR for the used IP address. Finally: I am not sure if this has any impact on TLS or not.
I always import the all intermediate certs for each cert I import. That means I install the two public intermediate certs twice and install the internal root and intermediate cert also twice. It might be sufficient to install both sets only once but I have never tested this. Who can tell if I am forcing myself into too much work or not?
I hope you solve your problem. My experience is that starting with certificates is most of the time a PITA (Pain In The Ass) but if you have figured out how to do it for a particular system it becomes quite simple.
Best regards
Steven

Error in Server log of one of the server on the clustered environment(OBI)

Hi
We had setup Clustered Environment and when we are trying to log in on to the Primary Server which is also Primary Controller, everything is fine on front end but we had faced the following error in the server log as follows : "[46036] Internal Assertion: Condition m_hFile != hFileNull, file .\Src\mfcfile.cpp, line 447."
Please provide help by letting me know what this error mean and how can we avoid this error.

What happens if you disable your master BI server, do you get the error in the other BI Server log when you login to Presentation Services?
The message is an internal error, you need to raise an SR with Oracle to determine why it's happening and how to prevent it.

WebLogic clustering Environment ...

          Hi,
          I have an clustering environment setup ( and see several issues) and was wondering
          if anyone else is having the same kind or are seeing similar issues.
          1) Have a weblogic proxy on win2000 box
          2) have two weblogic instances on another win2000 box.
          3) have two weblogic instances on third win2000 box.
          4) have db and 2 app servers on HPUX box.
          Questions:
          1) Does anyone have this kind of environment running successfully?
          2) Our stuff runs but we see several problems :
          --- sometimes we see blank page which comes back with actual page upon hitting
          refresh
          --- Several images don't show up. It tries to look for images on proxy server
          cache, but does not find it over there. It is in fact in the cache directory on
          one of the weblogic instances.
          --- I log in as one user and then log in as another user, it still brings
          up the page for the previous user.
          Can anyone throw some light on this issues or config.
          Any help / effort is greatly appreciated
          Thanks
          Bharat


If you have a significant site (heavy enough traffic or HLA requirement to
          use >1 proxy) then I suggest putting the static stuff on the proxy or even
          outside of the WL loop altogether. Generally speaking, it is fine to put it
          on the proxy, though, like on Apache.
          Here's the problem, though -- most apps hard-code the relative locations of
          the images. I suggest using a JSP tag for "image path" that uses property
          (config) information to deref the location of the files. That way you can
          dev on a single workstation and deploy to a single server or cluster or
          cluster with a set of proxies out front.
          Peace,
          Cameron Purdy
          Tangosol, Inc.
          http://www.tangosol.com
          +1.617.623.5782
          WebLogic Consulting Available
          "Joe" <[email protected]> wrote in message
          news:3a7a0b6f$[email protected]..
          >
          > I want to ask where should I put the images file in clustered envirnment.
          In database
          > as BLOB object or in Web Server??????
          >
          > If I put images in web server then it seems to be difficult to maintain if
          the web
          > site is mutilangual. But if I put images in database then the internal
          network traffic
          > increase.
          >
          > what is common practice for this issue??????

InvalidClientId on Clustered Environment

          I am running into a problem where a get "weblogic.jms.common.InvalidClientIDException:
          Client id, testDesintation, is in use" when running in a clustered environment.
          In the code, I dynamically set the clientId on the TopicConnection using setClientID().
          The class that does this is called from a Stateless Session EJB (clustered) which
          is called from a MDB (clustered).
          I believe this is from node1 setting the clientId to 'x', and before node1 has
          closed the connection, node2 opens a connection, setting the clientId to 'x'.
          This is how I actually need it to perform. Each node may need to publish messages
          to the same destination around the same time. This is because the clustered MDB
          is what prompts the publish to the next destination.
          What is the suggested approach for a problem such as this? Is the only solution
          not to cluster the MDB, so that only one node may be publishing to the Topic at
          one time?
          Any suggestions?
          jz


Hi Josh,
          I think that setting the client-id on a connection to force exclusivity is only needed
          when the connection is used to create a durable subscription. Even
          in this case some implementations of JMS may not require it, (don't
          recall for WebLogic.)
          So in your case, it is not necessary to set the clientId on a connection.
          Tom
          Josh Zook wrote:
          > I am running into a problem where a get "weblogic.jms.common.InvalidClientIDException:
          > Client id, testDesintation, is in use" when running in a clustered environment.
          > In the code, I dynamically set the clientId on the TopicConnection using setClientID().
          > The class that does this is called from a Stateless Session EJB (clustered) which
          > is called from a MDB (clustered).
          >
          > I believe this is from node1 setting the clientId to 'x', and before node1 has
          > closed the connection, node2 opens a connection, setting the clientId to 'x'.
          >
          > This is how I actually need it to perform. Each node may need to publish messages
          > to the same destination around the same time. This is because the clustered MDB
          > is what prompts the publish to the next destination.
          >
          > What is the suggested approach for a problem such as this? Is the only solution
          > not to cluster the MDB, so that only one node may be publishing to the Topic at
          > one time?
          >
          > Any suggestions?
          >
          > jz

Data Caching in a Clustered Environment

          I want to cache read-only reference/code table data that will run in a clustered
          WLS6 environment. It's a JSP application and I am storing a complete HTML Select
          Control per reference/code table data in the cache. The question is where to
          cache it? I was going to put it in the ServletContext (JSP "application" implicit
          object), but the ServletContext is not replicated. I considered using JNDI, but
          there are problems with duplicate name errors when another server who doesn't
          originally bind the object tries to lookup, change and rebind the object. I guess
          JMS Multicasting is an option, but I don't want to implement JMS just for an application
          data cache.
          Any suggestions for a simple reference/code table read-only caching strategy that
          will work in a clustered WLS6 environment?


If the data is strictly read-only, and you do not have to worry about cache
          integrity, then look at WebLogic JSP cachetag:
          http://www.weblogic.com/docs51/classdocs/API_jsp.html#cachetag
          You can use it to cache both the output and the calculations results
          (variables calculated inside the cache tag).
          The scenario will be exactly the same for non-clustered and clustered
          cases - using multicast to broadcast small invalidation messages (so the
          data can be refreshed from the database) is ok, but replicating application
          data is not (and you definitely do not want to use JNDI for this purpose).
          BTW, the initial CacheTag implementation in 5.1 (supposedly) had a 'cluster'
          scope and I assume it was multicasting fresh data after cache miss - there
          is no such scope in 6.0 implementation.
          If you still want replication you can look at javagroups:
          http://sourceforge.net/projects/javagroups/
          (distributedhashtable example).
          Olsen <[email protected]> wrote:
          > Cameron,
          > Thanks for the reply. However, as I stated below, I am not interested in
          > JMS, nor an EJB solution to the problem. It really is not that complicated of
          > a concept and I know a solution or two (ServletContext, JNDI), but none that works
          > in a WLS6 clustered environment.
          > Any other ideas???
          > Thanks...
          > "Cameron Purdy" <[email protected]> wrote:
          >>Dimitri had a clever (as ever) solution using JMS to maintain cache
          >>integrity:
          >>
          >>explanation at
          >>http://dima.dhs.org/misc/readOnlyUpdates.html
          >>
          >>d/l from
          >>http://dima.dhs.org/misc/readOnlyUpdates.jar
          >>
          >>--
          >>Cameron Purdy
          >>Tangosol, Inc.
          >>http://www.tangosol.com
          >>+1.617.623.5782
          >>WebLogic Consulting Available
          >>
          >>
          >>"Olsen" <[email protected]> wrote in message
          >>news:[email protected]...
          >>>
          >>> I want to cache read-only reference/code table data that will run in
          >>a
          >>clustered
          >>> WLS6 environment. It's a JSP application and I am storing a complete
          >>HTML
          >>Select
          >>> Control per reference/code table data in the cache. The question is
          >>where
          >>to
          >>> cache it? I was going to put it in the ServletContext (JSP "application"
          >>implicit
          >>> object), but the ServletContext is not replicated. I considered using
          >>JNDI, but
          >>> there are problems with duplicate name errors when another server who
          >>doesn't
          >>> originally bind the object tries to lookup, change and rebind the object.
          >>I guess
          >>> JMS Multicasting is an option, but I don't want to implement JMS just
          >>for
          >>an application
          >>> data cache.
          >>> Any suggestions for a simple reference/code table read-only caching
          >>strategy that
          >>> will work in a clustered WLS6 environment?
          >>
          >>
          Dimitri

MSTDC Error in clustered Environment in while interacting to DB Server from BizTalk server

Hi All,
After completing all my required Biz-talk Integrations (All were related to WCF-Custom Adapter : SQL Binding), I deployed the same to the client environment. But, the same thing which worked for me in my development environment was giving some issues in
the deployed environment.
The main difference was, at client environment - The DB Server was clustered environment and the interaction was through the load balancer.
The first issue I encountered was, there was firewall blocking the access to the DB server from Biz Talk server. Then after enabling and opening the Port 1433, the issue got fixed and I was able to communicate with the DB Server.
After this, I was getting the error related to MSTDC. For this to work properly, in my BizTalk application Configuration, if i set the property for "UseAmbientTransaction" as false under "SqlBinding" for the WCF-Custom Send Port, it is
working as expected!
But, I heard from our Architects that the best approach is to set the property as "TRUE" for "UseAmbientTransaction" property.
So I set the property as true and done the below configurations.
1. Enabling Network DTC using "dcomcnfg.exe"
2. Adding and enabling Fire wall exception for DTC.
Even after making the above changes, I was getting the same error. Then after cross checking with DTCPing and DCTester on both local and deployed copy, i got the below difference.
1. Port 135 (RPC EPM) was opened in my local environment but it was having "Filtered" access at the deployed copy.
So my question is, after opening the above port, will it solve the issue?
Secondly, is there any security threat ter opening the above Port?
Any quick suggestion/solution is highly appreciated.
Thanks in Advance,
Anand

Hi Anand,
Performing operations on SQL Server using BizTalk Server always involves two resources—the adapter connecting to SQL Server and the BizTalk Message Box residing on SQL Server. Hence, all operations performed using BizTalk Server are performed within the
scope of an MSDTC transaction. So, to use the SQL adapter with BizTalk Server, you must always enable MSDTC. To enable the adapter to perform operations within the scope of an MSDTC transaction, you must configure MSDTC both on the computer running the SQL
adapter and SQL Server. Also, you must add MSDTC to the exceptions list of Windows Firewall. That is the reason why recommend setting for this binding property is
true; otherwise you might either experience message loss or duplicate messages, depending on whether you are performing inbound or outbound operations.
Exception is for operations where the adapter client does not write any data to the SQL Server database, such as a Select operation, you might not want the additional overhead of performing the operations inside a transaction. In such cases,
you can configure the SQL adapter to perform operations without a transactional context by setting the
UseAmbientTransaction binding property to false.
Just refer the link fo all the details:
Configure MSDTC on SQL Server and Adapter Client
Rachit
Rachit
Please mark as answer or vote as helpful if my reply does

JMS in Clustered Environment

Hi All,
We have a clustered environment ; instance A and B of the same application server is running. Both the servers are configured for a JMS queue. But when I send message to the queue to refreh certain data, only one server is getting refreshed.
What can I do for this? Please suggest?
Regards
Sajitha

Hi,
You should tell us which product you are using. However, I think that you should use a topic rather than a queue because a message that is sent to a clustered queue will be delivered to only one MDB instance.
Hope it helps
Arnaud
www.arjuna.com

EJB deployment descriptors in clustered environment

          I was wondering how EJB deployment descriptor settings work in a clustered environment. Are the deployment descriptors per WebLogic instance they are deployed in or the entire clustered environment? For example, if my descriptor for a stateless session ejb has max-beans-in-free-pool set to 5 and I deploy this stateless ejb in 4 WebLogic instances of one cluster, does this mean that there will be a max of 5 instance of this bean in the free pool for the entire cluster or will there be a max of 20 (5 per WebLogic instance and 4 WebLogic instances in the cluster) instances of this bean for the entire cluster?
          Thanks,
          Bryan


Those settings are per server instance.
          Cameron Purdy
          Tangosol, Inc.
          http://www.tangosol.com
          +1.617.623.5782
          WebLogic Consulting Available
          "Bryan Dixon" <[email protected]> wrote in message
          news:3a6b51a0$[email protected]..
          >
          > I was wondering how EJB deployment descriptor settings work in a clustered
          environment. Are the deployment descriptors per WebLogic instance they are
          deployed in or the entire clustered environment? For example, if my
          descriptor for a stateless session ejb has max-beans-in-free-pool set to 5
          and I deploy this stateless ejb in 4 WebLogic instances of one cluster, does
          this mean that there will be a max of 5 instance of this bean in the free
          pool for the entire cluster or will there be a max of 20 (5 per WebLogic
          instance and 4 WebLogic instances in the cluster) instances of this bean for
          the entire cluster?
          >
          > Thanks,
          > Bryan
          >

Singleton behaviour in clustered environment

Hi,
          I have a very basic question. In a WebLogic clustered
          environment, is a Singleton replicated? In other words, if the
          mySingleton on node A in a cluster is updated with a piece of data,
          will this show in the mySingleton in node B?
          Thanks
          Ciao
          Ferruccio


No. If you need this type of functionality, use Coherence.
          http://www.tangosol.com/coherence.jsp
          Peace,
          Cameron Purdy
          Tangosol, Inc.
          http://www.tangosol.com/coherence.jsp
          Tangosol Coherence: Clustered Replicated Cache for Weblogic
          "Ferruccio" <[email protected]> wrote in message
          news:[email protected]..
          > Hi,
          > I have a very basic question. In a WebLogic clustered
          > environment, is a Singleton replicated? In other words, if the
          > mySingleton on node A in a cluster is updated with a piece of data,
          > will this show in the mySingleton in node B?
          >
          > Thanks
          >
          > Ciao
          > Ferruccio

Message Delivery in a Clustered Environment

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