JNDI spanning multiple clusters

          Hi!
          I would like to know if it is possible to have multiple
          clusters of servers (potentially in different network
          zones), and still have a global JNDI tree, as if it
          was only one big cluster? What are the considerations
          to meet such a requirement?
          Thanks,
          Guillaume Bedard

Generally speaking, you usually end up with multiple clusters with scenarios
          like this, each separated by a firewall for example.
          Peace,
          Cameron Purdy
          Tangosol, Inc.
          Clustering Weblogic? You're either using Coherence, or you should be!
          Download a Tangosol Coherence eval today at http://www.tangosol.com/
          "Guillaume Bedard" <[email protected]> wrote in message
          news:[email protected]...
          >
          > The client here "needs" to split the whole cluster into
          > sub-clusters in different security zones.
          >
          > Reading through the documentation, it says that it should
          > work as long as all the servers can subscribe and listen
          > to a single multicast IP address, but I am suspecting
          > that the particular network setup (firewalls) might
          > prevent us from having it working...
          >
          > Guillaume
          >
          > "Cameron Purdy" <[email protected]> wrote:
          > >Not really. The JNDI tree replication is done at the cluster-level and
          > >Weblogic doesn't have a concept of a "set" of clusters that communicate.
          > >
          > >What are you trying to accomplish with this approach?
          > >
          > >Peace,
          > >
          > >--
          > >Cameron Purdy
          > >Tangosol, Inc.
          > >Clustering Weblogic? You're either using Coherence, or you should be!
          > >Download a Tangosol Coherence eval today at http://www.tangosol.com/
          > >
          > >
          > >
          > >"Guillaume Bedard" <[email protected]> wrote in message
          > >news:[email protected]...
          > >>
          > >> Hi!
          > >>
          > >> I would like to know if it is possible to have multiple
          > >> clusters of servers (potentially in different network
          > >> zones), and still have a global JNDI tree, as if it
          > >> was only one big cluster? What are the considerations
          > >> to meet such a requirement?
          > >>
          > >> Thanks,
          > >>
          > >> Guillaume Bedard
          > >
          > >
          >

Similar Messages

Distributed Destination and multiple clusters

We have two clusters; each consisting of two managed servers. Can I create a single distributed JMS destination for BOTH clusters? If yes, how? If no, what is the best alternative so that I do not have to change the application for JMSqueue name?
          Thank you for your help.
          Vipul

Distributed destinations do not span between clusters.
          You can configure two distributed destinations, each with the same JNDI name. The JNDI names will not conflict as they will be in two different clusters. Clients that refer to the JNDI name will end up communicating with the distributed destination that's in the same cluster as their JNDI context...
          Tom

Connecting to multiple clusters using WAR file

I am trying to connect to multiple clusters by creating separate WAR(web archive) files through Apache tomcat.
My intention is to have each 'war' act as a node to a separate cluster. I started with the 'jmx-console' example available on the Tangosol website.
So, my understanding is that even though all the war files are loaded in the same JVM (tomcat), since each of these war's has its own classloader, we can have multiple tangosol ndoes from the same JVM.
So I have two basic questions:
*) If I use system.setProperty("tangosol.coherence.override", myOverrideFile-x) in the class loader of each WAR, can I have the nodes connect to different clusters. is'nt the System.setProperty() setting the property on the JVM? If so, how can multiple classloaders running in the same JVM connect to different clusters?
*) Where should I place config/override xml files under the tomcat directory structure for it to be accesible to the class loader.

Hi sumax,
Thanks for your response Robert,
Maybe I did not understand your solution fully, I
thought your idea mostly talks about how to configure
the override files, and not how to configure the
individual nodes to use different override files.
That part is taken care of by the fact, that each war file loads the tangosol-coherence-override.xml from its own WEB-INF/classes directory.
Classloading from a web app in Tomcat resolves classpath classes/resources in the following order:
1. java.* and javax.* and com.sun.* packages are loaded from the system classloader. This, I believe, cannot be circumvented on a Sun JVM with a classloader extending a JDK classloader class.
2. Reloadable JSP classloader (loads servlet classes generated from JSP pages). This is webapp specific, each webapp sees its own generated servlet classes.
3. Reloadable Webapp classloader (loads from WEB-INF/classes and WEB-INF/lib of the war). This is webapp specific, each webapp sees its own WEB-INF/classes and WEB-INF/lib.
4. Common classloader (loads from ${TOMCAT_HOME}/common/classes and ${TOMCAT_HOME}/common/lib). This is used by all webapps and the Tomcat container itself. You should not put anything here, except for libraries for resource drivers, etc. JDBC drivers or anything which needs to be published in the JNDI server in a non-application-specific way.
5. Shared classloader (loads from ${TOMCAT_HOME}/shared/classes and ${TOMCAT_HOME}/shared/lib). This is shared between all webapps but not by the Tomcat container. You can put libraries here with which you want to communicate between webapps. Any singletons in classes in this classloader will be shared between webapps. A place for configuration files which are shared or if they have the application name in their filenames (so that they are not accidentally used by another application).
The question still lingering in my mind is:
How do I tell the classloader which override file to
load.
A tangosol-coherence-override.xml with different content should be put in the WEB-INF/classes directory of each war file. Each of those files will be loaded only by its containing webapp. This filename is defined in the deployment-mode-specific override files in coherence.jar or tangosol.jar (I don't remember which, off my head) which all chain to this same tangosol-coherence-override.xml file.
That override file can contain all your overrides, if you do not want to change those between restarts, or it can chain with its xml-override attribute (as shown in the example) to another file with the application name in its filename.
This chaining allows each webapp to refer to a differently named override file, so all those override files can be put into shared/classes folder. The uniquely named override file in shared/classes allows you to change the override configuration between restarts.
As for cluster address and port, you can specify those in any of the override files.
The full chaining path is the following (if you used the tangosol-coherence-override.xml example in my first reply):
tangosol-coherence.xml -> tangosol-coherence-prod.xml -> tangosol-coherence.xml (you provide this file in your webapp WEB-INF/classes) -> tangosol-coherence-override-warfilename.xml (you provide this file in the ${TOMCAT_HOME}/shared/classes)
I hope this makes it clear.
Best regards,
Robert

How to configure multiple clusters on the same machine.

I am attempting to configure multiple clusters on the same set of machines. I have set the cluster name and multicase IP addresses to be different for each cluster. However I am still getting and error that states:
"This indicates that there are multiple clusters on this network attempting to use overlapping network configurations."
Is this not possible? If it is possible, is there some further way i need to tell the VMs they are part of different clusters?
Thanks,
Jacob

FYI: I'm using the wrong multicast IP above. 224.0.0.1 is reserved and something else should be used. See:
Re: UDP flood hosed my LAN?

Multiple clusters on a single machine

Hi everyone. I have a question about running 2 clusters on a same
          machine.
          Here's the scenario. We have 8 WebLogic server (4.5.1 SP4) instances
          running on
          2 servers (Sun Enterprise 5500/Solaris 2.62) right now for one of our
          eCommerce
          application.
          Now we are getting ready to deploy a 2nd application and we want it to
          have its
          own cluster. So we are hoping to run 4 more WebLogic servers on each of
          the 2
          machines. So machine #1 would have 4 WebLogic servers for cluster A and
          4
          WebLogic servers for cluster B. And machine #2 will have 4 WebLogic
          servers for
          cluster A and 4 WebLogic servers for cluster B.
          All of these servers have unique IP address and each cluster has a
          different
          name and multicast IP address. Both clusters are using in-memory
          replication.
          On both machines, each of the cluster member will share the same global
          weblogic.properties file. The cluster specific portion resides in the
          cluster
          directory.
          Is anyone currently running such a configuration?? Is there something
          we should
          worry about?? Since both of these servers are in their own isolate
          network
          segment, is there any danger of multicast broadcast bleeding into the
          different
          cluster?? Thanks in advance.


Hi Michael and thanks.. No, this is 2 systems on the same network and not two
          independent networks. Here's what I found that's very strange. I started
          server 1 ->4 for the first cluster and everything worked fine. Now I started
          server 5 on the first machine that's in a different cluster and has a totally
          different multicast IP address and yet, server 1 of the first cluster recorded
          server 5 joining the cluster. Server 2, 3 and 4 of the first cluster did not
          have RJVM 'Creating connection' message in there.
          On server 5's startup, server 1 decided to make server 5 it's secondary pair and
          I get the following error as server 5 does not have the same code for cluster1.
          After that error, I started getting tons of
          weblogic.cluster.replication.BadStatusException error in the logs for server 1
          listed below. I'm sure running multiple clusters off an enterprise level
          server is something people want to do. Is this a known issue?? Is this a bug
          in the server or the VM?
          Our environment: Sun 5500 Enterprise servers running Solaris 2.62, WebLogic
          4.5.1 SP4.
          Sun Jan 09 15:19:40 CST 2000:<I> <RJVM> Creating connection to
          stingray05.xx.com/10.x.x.x t3:7001 http:7001 t3s:7002 https:7002
          -1353087187406741800
          Sun Jan 09 15:19:41 CST 2000:<E> <MulticastSocket> Multicast socket receive
          error:
          Sun Jan 09 15:19:41 CST 2000:<E> <MulticastSocket>
          java.lang.ClassNotFoundException: Could not instantiate new instance of
          [com.strong.brokerage.server.CustomerSessionBeanHomeImpl_WLStub]
          Either the class is missing from classpath, the class does not have a public
          constructor, or the constructor raised an error; the actual exception was a :
          java.lang.NoClassDefFoundError: com.strong.brokerage.common.util.RegistrationCtx
          at java.lang.Throwable.<init>(Compiled Code)
          at java.lang.Exception.<init>(Compiled Code)
          at java.lang.ClassNotFoundException.<init>(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readLeftover(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectBody(Compiled Code)
          at weblogic.common.internal.WLObjectInputStreamBase.readObject(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectWL(Compiled Code)
          at weblogic.service.ReplicaAggregate.readExternal(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readPublicSerializable(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readLeftover(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectBody(Compiled Code)
          at weblogic.common.internal.WLObjectInputStreamBase.readObject(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectWL(Compiled Code)
          at weblogic.cluster.BasicServiceOffer.readObject(Compiled Code)
          at weblogic.cluster.AnnotatedServiceOffer.readObject(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readPublicSerializable(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readLeftover(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectBody(Compiled Code)
          at weblogic.common.internal.WLObjectInputStreamBase.readObject(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectWL(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readArrayList(Compiled Code)
          at weblogic.cluster.Announcement.readObject(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readPublicSerializable(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readLeftover(Compiled Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectBody(Compiled Code)
          at weblogic.common.internal.WLObjectInputStreamBase.readObject(Compiled
          Code)
          at
          weblogic.common.internal.WLObjectInputStreamBase.readObjectWL(Compiled Code)
          at weblogic.cluster.TMSocket.execute(Compiled Code)
          at weblogic.t3.srvr.ExecuteThread.run(Compiled Code)
          Sun Jan 09 15:24:42 CST 2000:<E> <HTTP> Servlet request terminiated with Error:
          Sun Jan 09 15:24:42 CST 2000:<E> <HTTP>
          weblogic.cluster.replication.BadStatusException: update found
          -5050872662681587012 but it is not the secondary
          at weblogic.rmi.extensions.BasicRequest.sendReceive(Compiled Code)
          at
          weblogic.cluster.replication.ReplicationManager_WLStub.update(Compiled Code)
          at
          weblogic.cluster.replication.ReplicationManager.updateSecondary(Compiled Code)
          at weblogic.servlet.internal.session.ReplicatedSession.sync(Compiled
          Code)
          at
          weblogic.servlet.internal.session.ReplicatedSessionContext.sync(Compiled Code)
          at weblogic.servlet.internal.ServletRequestImpl.syncSession(Compiled
          Code)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
          Code)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled
          Code)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled
          Code)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.execute(Compiled Code)
          at weblogic.t3.srvr.ExecuteThread.run(Compiled Code)
          --------------- nested within: ------------------
          weblogic.utils.NestedError: Tried to update secondary, but it thought it was the
          primary
          - with nested exception:
          [weblogic.cluster.replication.BadStatusException: update found
          -5050872662681587012 but it is not the secondary]
          at java.lang.Throwable.<init>(Compiled Code)
          at java.lang.Error.<init>(Compiled Code)
          at weblogic.utils.NestedError.<init>(Compiled Code)
          at weblogic.servlet.internal.session.ReplicatedSession.sync(Compiled
          Code)
          at
          weblogic.servlet.internal.session.ReplicatedSessionContext.sync(Compiled Code)
          at weblogic.servlet.internal.ServletRequestImpl.syncSession(Compiled
          Code)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
          Code)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled
          Code)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled
          Code)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.execute(Compiled Code)
          at weblogic.t3.srvr.ExecuteThread.run(Compiled Code)
          Michael Girdley wrote:
          > Vinny,
          >
          > It sounds like the real hard problem here is a system administration and
          > configuration issue. If you have two independent networks with independent
          > systems, then you should not have a problem running two clusters across two
          > machines. You just need to make sure that your routing for multicast is
          > appropriately configured so that they don't confuse the two different
          > WebLogic server clusters.
          >
          > I hope this helps. I might also recommend contacting our sales organization
          > who can put you in touch with a systems engineer who is a professional at
          > making these types are recommendations.
          >
          > Thanks!
          >
          > --
          > Michael Girdley
          > BEA Product Manager
          >
          > Vinny Carpenter <[email protected]> wrote in message
          > news:[email protected]...
          > > Hi everyone. I have a question about running 2 clusters on a same
          > > machine.
          > > Here's the scenario. We have 8 WebLogic server (4.5.1 SP4) instances
          > > running on
          > > 2 servers (Sun Enterprise 5500/Solaris 2.62) right now for one of our
          > > eCommerce
          > > application.
          > >
          > > Now we are getting ready to deploy a 2nd application and we want it to
          > > have its
          > > own cluster. So we are hoping to run 4 more WebLogic servers on each of
          > > the 2
          > > machines. So machine #1 would have 4 WebLogic servers for cluster A and
          > > 4
          > > WebLogic servers for cluster B. And machine #2 will have 4 WebLogic
          > > servers for
          > > cluster A and 4 WebLogic servers for cluster B.
          > >
          > > All of these servers have unique IP address and each cluster has a
          > > different
          > > name and multicast IP address. Both clusters are using in-memory
          > > replication.
          > > On both machines, each of the cluster member will share the same global
          > > weblogic.properties file. The cluster specific portion resides in the
          > > cluster
          > > directory.
          > >
          > > Is anyone currently running such a configuration?? Is there something
          > > we should
          > > worry about?? Since both of these servers are in their own isolate
          > > network
          > > segment, is there any danger of multicast broadcast bleeding into the
          > > different
          > > cluster?? Thanks in advance.
          > >
          > >
          > >
          > >

Events Spanning Multiple Days

I'm converting to iCal from another application I've used for years. Does iCal support any way to insert and display a line, banner, bar, etc. accross multiple days in the Month View so that I can display the fact that I'm on the road or on vacation, etc. for the days covered by the line, banner, bar, etc?
I would be happy to provide a picture of what the application I've been using does to support this need.
PowerBook G4 Mac OS X (10.4.8) iCal v2.0.4 (1055)

Regal909,
Is this what you are looking for? Creating an all-day or multi-day event:You can create an event that lasts one or more complete days (for example, for a vacation), or an event that spans multiple days with different start and end times.
To create an all-day event, make sure you're in Day or Week view, then double-click in the white area at the top of the iCal window (just below the date). If you want your all-day event to last multiple days, drag a corner of the event across the days in the main calendar view (or type the end date in the Info drawer).
To create a multi-day event, make sure you're in Day or Week view, then drag from the start time to the end time of the event (you can drag across multiple days). You can also type the start and end dates and times in the event's Info drawer.
All-day events are shown across the top of the day in the main calendar view.   
Tip: You can also make any event an all-day event by selecting the "all-day event" checkbox in the event's Info drawer.;~)

How can I copy text spanning multiple pages in iBook?

I like to drop sections of text from i
books into letters, journal entries etc and for the life of me I cannot figure out the functionality of grabbing text that spans multiple pages.

Hi James,
Thank you so much for taking the time to help me out. You actually solved the problem. I am able to select as much text as I want now. The bummer is the lame feature where you cannot take more than a couple hundred words at a time. The section I wanted was about one and a half pages and it took me 3 separate copy pastes to get it all. Does anyone know of software or a trick to overcome this limitation?
James thanks again. I really appreciate your help.

Can join queries in Oracle 8i and above span multiple databases

Hi,
In Oracle 8i and above, can join queries span multiple databases??
For eg., I have two databases A and B, and say database A has table A_T and
database B has table B_T. Assume that both the databases are on the same
server.
Can I run a join query from my application using OCI calls that spans across
tables from multiple databases, namely, A_T and B_T?
My query probably looks like this - Select * from A.A_T, B.B_T;
Thank you,
Sashi

In Oracle 8i and above, can join queries span multiple databases??
For eg., I have two databases A and B, and say database A has table A_T and
database B has table B_T. Assume that both the databases are on the same
server.
Can I run a join query from my application using OCI calls that spans across
tables from multiple databases, namely, A_T and B_T?
My query probably looks like this - Select * from A.A_T, B.B_T;If you create a database link from database A to B your SQL would look something like this:
select * from A.A_T, B.B_T@dbB where A.A_T.PK = B.B_T.PK@dbB
The Oracle manuals should have the information you need on creating a database link.

Load-balancing issues with iPlanet and multiple clusters

We're in performance test of a large-scale clustered deployment based on WLS 5.1sp10.
Due to scalability/functionality issues, some of which we've seen firsthand and
some of which we've been informed of by associates as well as BEA representatives,
we've chosen to implement multiple clusters with a maximum of three nodes each.
These clusters will be fronted by a web server tier consisting of iPlanet servers
using the proxy plugin.
Due to hardware constraints (both in test and in production), however, we've configured
the iPlanet servers to route across the multiple clusters. In our test environment,
for instance, we've got a single iPlanet server routing across two 3-node clusters,
and the configuration in obj.conf is as follows:
<Object name="application" ppath="*/application">
Service fn="wl-proxy" \
WebLogicCluster="clusterA_1:9990,clusterB_1:9991,clusterA_2:9990,clusterB_2:9991,clusterA_3:9990,
clusterB_3:9991" \
CookieName="ApplicationSession"
</Object>
Our issue is that the load-balancing doesn't appear to work across the clusters.
We're seeing one cluster get about 90% of the load, while the other receives
only 10%.
So, the question (finally!) is: Is this configuration correct (i.e., will it
work according to the logic of the proxy plugin), and is it appropriate for this
situation? Are there other alternative approaches that anyone can recommend?
Thanks in advance,
cramer

I use weblogic6.1 with sp2+windows 2000.I develop a web application and deploy
it to cluster.Through HttpClusterServlets proxy of weblogic I found that a server
in cluster almost get 95% of requests but another only get 5% of requests.Why???
I don't set any special parameter.And the weight of the two clustered server is
equal.I use round-robin arithmetic.
Thanks!
"cramer" <[email protected]> wrote:
>
We're in performance test of a large-scale clustered deployment based
on WLS 5.1sp10.
Due to scalability/functionality issues, some of which we've seen firsthand
and
some of which we've been informed of by associates as well as BEA representatives,
we've chosen to implement multiple clusters with a maximum of three nodes
each.
These clusters will be fronted by a web server tier consisting of iPlanet
servers
using the proxy plugin.
Due to hardware constraints (both in test and in production), however,
we've configured
the iPlanet servers to route across the multiple clusters. In our test
environment,
for instance, we've got a single iPlanet server routing across two 3-node
clusters,
and the configuration in obj.conf is as follows:
<Object name="application" ppath="*/application">
Service fn="wl-proxy" \
WebLogicCluster="clusterA_1:9990,clusterB_1:9991,clusterA_2:9990,clusterB_2:9991,clusterA_3:9990,
clusterB_3:9991" \
CookieName="ApplicationSession"
</Object>
Our issue is that the load-balancing doesn't appear to work across the
clusters.
We're seeing one cluster get about 90% of the load, while the other
receives
only 10%.
So, the question (finally!) is: Is this configuration correct (i.e.,
will it
work according to the logic of the proxy plugin), and is it appropriate
for this
situation? Are there other alternative approaches that anyone can recommend?
Thanks in advance,
cramer

How best to make a transaction span multiple HTTP requests?

Hi, all. What is the best way to implement a transaction that spans multiple
HTTP requests? Many J2EE applications must solve this problem, but I can't
any guidelines for an implementation.
Consider an application that implements a multi-step wizard. Each step
gathers data from the user; step one gets the user's name, and step two gets
his dog's name. When the user completes the wizard, the application saves
the user & dog in two entity beans. Conceptually, the application treats
this wizard like a single, long-running transaction. The transaction begins
when the user launches the wizard. Submitting the JSP for step one adds the
Boy bean to the transaction, and submitting step two adds the Dog bean.
Finishing the wizard commits the transaction. Exiting the wizard or timing
out causes the transaction to rollback.
Although the wizard looks like a transaction, the entire sequence of user
interactions can't be captured in a single JTA UserTransaction. A
UserTransaction must be associated with a single thread, but each wizard
step is handled asynchronously by its own execution thread. It's impossible
to funnel the conversation through one thread that can demarcate the
transaction. (This would be a pretty dumb solution for other reasons, but I
don't want to get lost in details.)
I think the standard way to solve this problem is to store conversation
state in a stateful session bean (or the http session) and create / update
both entity beans in a transactional EJB method after the wizard completes.
Unfortunately, this solution prevents me from leveraging a lot of great
transaction management features provided by the app server. For example, I
can't use optimistic concurrency to make sure that the dog object hasn't
changed in the database between the start and end of the wizard. Also, I'm
forced to keep track of changes to the dog object in the conversation state,
then replicate these changes to an entity bean at the end of the wizard.
Keeping track of state in a stateful bean is pretty straightforward, but it
seems like there must be an existing solution that leverages the appserver's
concurrency and state management features. Am I missing something? Is there
code, a pattern, or an article that describes the best way to implement a
multi-step process that looks transactional? I suppose WLI does what I want,
but that feels like killing a roach with a SCUD missle. Thanks for any
advice.
Dave

Dave Smith wrote:
Without a transaction, will the app server manage the version column
automatically, assuming of course that <concurrency-strategy> is
"Optimistic" and <verify-columns> is set to "Version"? Of course, I'll have
to expose the version as a cmp-field, which is fine with me.Yes
>
Do you know offhand, so that I don't have to get off my lazy ass and write a
test, whether the CMP service will create the version column when it
generates db tables? (I realize it's not good to let WLS generate the tables
in a production system.)No, I don't think it does.
>
I assume from your answer that I'm on my own for implementing stuff like and
transaction inheritance and tracking object modifications? Well, we'll give you a bit of help on the object modifications. The
usual pattern is when you're pushing the JavaBean back to the CMP you
call all the setXXX methods on the CMP bean. Our CMP container will
check if the value you are setting is the same as read from the db. If
so, it will not update that column.
-- Rob
If so, no big
deal. I was just hoping somebody would say, "Oh, you want the Jakarta
SuperBeans project" or something.
Thanks,
Dave
"Rob Woollen" <[email protected]> wrote in message
news:[email protected]...
I'd recommend that you include a separate version or timestamp column in
your db schema.
Then do something like this:
Client Server
1) First HTTP Request
2) Read current Dog and Boy Entity Beans
(if any) and copy their values into a JavaBean.
You want to include the version
column(s) in the JavaBean(s) along with the data values.
You probably also want to store the JavaBeans in
your HTTP Session.
3) Client proceeds through wizard interacting with JavaBeans
4) Finish with Wizard, copy JavaBean values (including
version columns) to CMP 2.0 Entity Beans.
The version column will give you the optimistic concurrency protection
that you desire without opening a JTA transaction to span user input.
-- Rob
Dave Smith wrote:
Hi, all. What is the best way to implement a transaction that spans
multiple
HTTP requests? Many J2EE applications must solve this problem, but Ican't
any guidelines for an implementation.
Consider an application that implements a multi-step wizard. Each step
gathers data from the user; step one gets the user's name, and step twogets
his dog's name. When the user completes the wizard, the applicationsaves
the user & dog in two entity beans. Conceptually, the application treats
this wizard like a single, long-running transaction. The transactionbegins
when the user launches the wizard. Submitting the JSP for step one addsthe
Boy bean to the transaction, and submitting step two adds the Dog bean.
Finishing the wizard commits the transaction. Exiting the wizard ortiming
out causes the transaction to rollback.
Although the wizard looks like a transaction, the entire sequence ofuser
interactions can't be captured in a single JTA UserTransaction. A
UserTransaction must be associated with a single thread, but each wizard
step is handled asynchronously by its own execution thread. It'simpossible
to funnel the conversation through one thread that can demarcate the
transaction. (This would be a pretty dumb solution for other reasons,but I
don't want to get lost in details.)
I think the standard way to solve this problem is to store conversation
state in a stateful session bean (or the http session) and create /update
both entity beans in a transactional EJB method after the wizardcompletes.
Unfortunately, this solution prevents me from leveraging a lot of great
transaction management features provided by the app server. For example,I
can't use optimistic concurrency to make sure that the dog object hasn't
changed in the database between the start and end of the wizard. Also,I'm
forced to keep track of changes to the dog object in the conversationstate,
then replicate these changes to an entity bean at the end of the wizard.
Keeping track of state in a stateful bean is pretty straightforward, butit
seems like there must be an existing solution that leverages theappserver's
concurrency and state management features. Am I missing something? Isthere
code, a pattern, or an article that describes the best way to implementa
multi-step process that looks transactional? I suppose WLI does what Iwant,
but that feels like killing a roach with a SCUD missle. Thanks for any
advice.
Dave

What is the difference of specifying affinity to span multiple caches?

What is the difference of methods between specifying affinity to span multiple caches and specifying it on a single cache?
Can I do it in the same way?

Thank you for reply.
From the Docs of Coherence we can see that the data affinity is commonly referred to the related entries is contained within a single cache. The following is some fragmentss excerpted from Coherence Docs:
"Data affinity describes the concept of ensuring that a group of related cache entries is contained within a single cache partition. This ensures that all relevant data is managed on a single primary cache node (without compromising fault-tolerance)."
"Affinity may span multiple caches (as long as they are managed by the same cache service, which will generally be the case)."

Multiple Clusters with same computers

Is there a way to set up multiple clusters with the same computers.
For example
Cluster A has computers 1, 2
Cluster B has computers 1, 2, 3, 4, 5
The reason behind this is that computers 1 and 2 are always available, but 3, 4, 5 are used during the day. I'd like to have a day cluster and a night cluster that I can just select as needed.

Hi Jake, I was playing with this type of thing when FCS1 first came out using some old powerbooks.
Yes you can kind of do this using UNMANAGED SERVICES but I will stand corrected for COMPRESSOR3.app.
In FCS2, compressor 3, simply if you use *MANAGED SERVICES* of the service nodes available through a defined a specific cluster (you would have used appleqmaster utility.app) than I believe those service nodes are dedicated to that cluster.
Sure you can make 'INSTANCES" of compressor for example and the 'renderer" instances dedicated to particular cluster using this as an example... let say...
HOST1 = MACPRO8CORE with 4 instances of compressor (as C1,C2,C3,C4 via vi 4 virtual clusters) and 8 instances of renderer (R1,R2,..R7 & R8).
HOST2 = MACBOOKPRO with 1 instance of compressor (as C1 & C2 with 2 virtual clusters) and 2 instances of renderer (R1,R2).
HOST3 = PowerbookG4 with 1 instance of compressor (as C1) and 1 instances of renderer (R1).
only as an example
ClusterA: Host1[C1,C2C3, R1,R2,R4,R5), Host2[C2]
ClusterB: Host1[C4, R6,R3,R6,R7), Host2[C2,R1R2], HOST3{C1,R1]
In fact I just tried it...
However as I thought for managed services be assured that you cannot SHARE a service node with two or more clusters. I will stand corrected.
Messy but seems to work but useless with the powerbook you'd agree
However depending on your workflow and commecrial needs (say for busness prioriries for a specific client) for best results use *UNMANAGED SERVICES* ....
Simply hook everything up over GBE, with all the usual tweaks such as "NEVER COPY SOURCE" and MOUNTING all source targets and compressor work files over HFS on the GBE subnet (and many other tweaks) and treat the set up as a huge bucket.
Use priority on the batch submission. It's not too smart but at least you have some manipulation over the queues.
The resource manager in QMASTER is not so smart. So despite a service node going idle it does not seem to redirect work from wone node to another for load balancing..
I have only tried this with SEGMENTED TRANSCODING.
Rendering (Shake) works great and seem simpler. My time is with multipass segented transcoding where I want H.264 from DVCPROHD and dont want to wait all day for it, especially where I have tweaked the timing in compressor a bit.
Try it out.
BTW as many contest on this forum, QMASTER/COMPRESSOR can be a bugger to fix if it plays up. and it has for me as well.
post your results.
HTH.
w

Premiere Pro won't span multiple monitors

Premier Pro CS3
I cannot get the PP app to span multiple monitors. Previously I have used Premiere to span two 22" monitors so I can have a very wide timeline. Now that I have installed CS3, it "takes over" my second monitor as a "Program" monitor and I cannot figure out how to shut it off. It also makes this monitor useless for any other applications that I have open while CS3 is open. Help!

Well, now it's working and I have NO CLUE WHY... perhaps opening and closing Premiere 5 times is required before the videocard gets into the act. In any case, it has just started working and I completed an entire editing sequence with no freaky behavior at all.
I love it when a plan comes together - but it's sure nice to know "why" for next time ocasionally... I did use an older saved sequence as a starting point this time, so perhaps something was corrupted in the "new workspace" that I tried to save.
Now, of course, I'm afraid to ever turn this computer off again, or even close Premiere...
Thanks to all for your help - you will all get a free autographed copy of my next book, "Dual Monitors for Dummies"...

Creating a dynamic table that spans multiple pages

Hi guys,
I have a script that is able to add rows to a dynamic table.
The issue I am having now is I want this dynamic table to span multiple pages.
I'm not exactly sure how to do this. It looks like to me that the table stops once it reaches the height of the text frame enclosing it.
How do you create a table / text frame that expands to it's contents and not the size of the text frame enclosing it. Ideally I want this table to span multiple pages.

OK, I have 3 screenshot to see if that will help. My book is a transcription of some old county records around 1800. I have a section of my book that had a list of items in text separated by a right tab.
I highlighted that text and converted it to a table. In portrait mode I can scroll and see all the table.
When I switch to landscape mode the table is cut off and does not wrap to the next page.
The text after the table appears on the next page. The preview on the ipad is the same.
Thanks for any help on figuring this out. Also, I enjoy your podcasts.
MB

Cell value spanning multiple rows in JTable

Hi,
I have a JTable where I want a single column value alone to span multiple rows.
Something like
Course No. | Location | Cost
| loc1 | 1000
1 ---------------------------------------------
| loc2 | 2000
How can I create a JTable like this?
Thanks for the help.

I have a link for that,
http://www2.gol.com/users/tame/
go in swing examples, JTable #4.
Hope it helps :)

JNDI spanning multiple clusters

Similar Messages

Maybe you are looking for