Questions on InitialContext and replica-aware stub caching

Hi All,
We have a cluster and deployed with some stateless ejb session beans. Currently we only cached the InitialContext object in the client code, and I have several questions:
1. in the current case, if we call lookup() to get a replica-aware stub, which server will return the stub object, the same server we get the InitialContext, or it will load balanced to other servers every time we call the lookup method?
2. should we just cache the stub? is it thread safe? if it is, how does the stub handle concurrent requests from the client threads? in parallels or in sequence?
One more question, when we call new InitialContext(), it will take a long time before it can return a timeout exception if the servers are not reachable, how can we set a timeout for this case?

809364 wrote:
You can set the timeout value programatically by using the
weblogic.jndi.Environment.setRequestTimeout()
Refer: http://docs.oracle.com/cd/E12839_01/apirefs.1111/e13941/weblogic/jndi/Environment.html
or
set the REQUEST_TIMEOUT in the weblogic.jndi.WLContext
Refer: http://docs.oracle.com/cd/E11035_01/wls100/javadocs/weblogic/jndi/WLContext.html
Hi, I tried setting the parameters before, but it only works for stub lookup and ejb call timeout, not for the creation of InitialContext. And any idea for my 2nd question?

Similar Messages

Is Replica aware stubs are in infinite loop when fail over????

          Hi
          Any help on this Appreciated
          See in this senario, where there is four weblogic instance runs in the cluster
          and a replica aware stub(stateless bean with idempodent methods) finds a particular
          method fails on a server and it redircets the request to another one server but the
          same method fails on all the server, then what is goin to happen?? is it going to
          throw some exception or gonna be in a loop to keep on redirecting the method request
          to all servers in Round???
          Regards
          Aruna


          Aruna,
          A stateless session bean whose methods have been declared idempotent will automatically
          retry on another service provider in a fail-over situation. When a fail-over situation
          occurs, the stub refreshes its list of service providers. Note: Just because your
          method call fails, doesn't mean it's a fail-over situation.
          Jane
          "Aruna" <[email protected]> wrote:
          >
          >Hi
          >
          > Any help on this Appreciated
          >
          > See in this senario, where there is four weblogic instance runs in
          >the cluster
          >and a replica aware stub(stateless bean with idempodent methods) finds a
          >particular
          >method fails on a server and it redircets the request to another one server
          >but the
          >same method fails on all the server, then what is goin to happen?? is it
          >going to
          >throw some exception or gonna be in a loop to keep on redirecting the method
          >request
          >to all servers in Round???
          >
          >
          >Regards
          >Aruna

Replica-aware stub.

Hi,
Can anyone explain about replica aware stub.
Thanks in advance.
Regards,
Vardhan.

Hi Vardhan,
Please refer to : http://download.oracle.com/docs/cd/E11035_01/wls100/cluster/overview.html
Load balancing and failover for EJBs and RMI objects is handled using replica-aware stubs, which can locate instances of the object throughout the cluster. Replica-aware stubs are created for EJBs and RMI objects as a result of the object compilation process. EJBs and RMI objects are deployed homogeneously—to all the server instances in the cluster.
Failover for EJBs and RMI objects is accomplished using the object’s replica-aware stub. When a client makes a call through a replica-aware stub to a service that fails, the stub detects the failure and retries the call on another replica. To understand failover support for different types of objects, see Replication and Failover for EJBs and RMIs.
WebLogic Server clusters support multiple algorithms for load balancing clustered EJBs and RMI objects: round-robin, weight-based, random, round-robin-affinity, weight-based-affinity, and random-affinity. By default, a WebLogic Server cluster will use the round-robin method. You can configure a cluster to use one of the other methods using the Administration Console. The method you select is maintained within the replica-aware stub obtained for clustered objects. For details, see Load Balancing for EJBs and RMI Objects.
Above kind of Stubs are available only for *"EJBs and RMI Objects"* when we deploy an EJB/RMI based application on Cluster.

RMI callbacks with no replica aware stubs in a cluster?

We would like to use either an RMI ping mechanism or an RMI callback in an upcoming project but are limited to 1.1 and 1.2 JRE's. I don't believe generating a replica aware proxy is an option for us given those constraints, no support for dynamic proxies. So we have a remote server object that we would ideally like to be clusterable that we can register a callback interface with. How can we accomplish this given our client limitations with weblogic 8.1 RMI? Any options?

Yep you speak no lies. Of course once I thought about it some more I realized the error of assuming one could register a jdk rmi object with a weblogic rmi object. JRMP vs T3?. Not good.
We still like using plain jane RMI w/in weblogic. I can register my UnicastRemoteObject stub with a normal RMI object on the server and it can callback and deliver messages. It will also send heartbeats periodically. If the heartbeat isn't heard from in awhile we re-register through http. The advantage of this is that the http session has failed over to another box and the web tier manages the rmi registration for me. The client can remain ignorant of any RMI lookups, which are tedious when not using JNDI or the cluster aware proxy.
All of this to get back a few seconds and keep a few thousand clients from polling through a servlet every second. Argh JDK 1.1.
Thanks for hammering that final point in.

Re-deploying replica aware EJBs

          How does one update an app server with a new EJB when the app server
          is running in a cluster? Doing a re-deploy on the EJB in a single instance
          can even be a problem. First, you can have beans that are cached and
          in use. locking the server and waiting until the last client has completed
          it's operation until you do the redeploy should work. With clustered SLSBs
          the replica aware stubs get distributed by JNDI so until all the servers
          in the cluster have the update the classes are out of sync.
          It seems like you have to bounce all the app servers in the cluster. Not
          a very amicable solution.


In article <[email protected]>, [email protected] says...
          >
          > How does one update an app server with a new EJB when the app server
          > is running in a cluster? Doing a re-deploy on the EJB in a single instance
          > can even be a problem. First, you can have beans that are cached and
          > in use. locking the server and waiting until the last client has completed
          > it's operation until you do the redeploy should work. With clustered SLSBs
          > the replica aware stubs get distributed by JNDI so until all the servers
          > in the cluster have the update the classes are out of sync.
          >
          > It seems like you have to bounce all the app servers in the cluster. Not
          > a very amicable solution.
          >
          >
          >
          Mike,
          This is a toughy and something I've been trying to figure out for a
          while. Maybe together we'll devise a strategy so here's what I've come
          up with so far:
          Maintain a set of "upgrade servers" on another network line (using a
          switch). When upgrading, bring them online into the main cluster and
          then start kiling the main machines. When they're all dead, unplug them
          from the network and begin the upgrade. Test the upgrade after bringing
          the new main cluster back up. Once confirmed, start locking out
          transactions, etc from the backup cluster and have the web front end
          give a "down for X minutes message to all new requests". Once the
          backup app servers have no more requests, unplug them from the network
          and plug the new app servers in. Reopen the flood gates at the front
          end. You'll still lose some sessions, but this should be in a service
          level agreement and be understood by customers.
          Some variations, in case the switch isn't manageable and being
          physically there is not on option would be to bring various interfaces
          up and down to meet the needs described above.
          It's not perfect; uptime is still purposely limited, but these are thing
          that should be defined in any agreement you make with customers. Even
          NASDAQ goes down. I'm currently working on a strategy for WebLogic 6.0
          JT

Replica aware

Hi,
          I am an absolute newbie in the world of web logic clustering. I am reading
          the article "How Clusters work" in WLS 5.1 documentation.
          I am not quite sure as to what do the term 'Replic aware'.
          It will be great if some one could explain that
          regards,
          Abhishek.


          Replica aware means this stub can be smart enough to know how many replicas(each replica means a deployed service on one server in the cluster) it represents and the detail information about these replicas(ie. it's ip address.)
          The replica-aware stub can support load-balance and fail over accroding to these information. suppose if one replica fails, the stub can remove this replica from this stub and fail over to other.
          Hope this can help you.
          Abhishek <abisheks@no_spam.india.hp.com> wrote:
          >Hi,
          >
          >I am an absolute newbie in the world of web logic clustering. I am reading
          >the article "How Clusters work" in WLS 5.1 documentation.
          >
          >I am not quite sure as to what do the term 'Replic aware'.
          >
          >It will be great if some one could explain that
          >
          >regards,
          >Abhishek.
          >

I noticed when I restart Firefox 4, it opens my previous tabs even I set the option "Open a blank page" and it opens blank page when I have "Show my windows and tabs from last time". Please ignore my question if you're already aware of this issue. Thanks.

I noticed when I restart Firefox 4, it opens my previous tabs even I set the option "Open a blank page" and it opens blank page when I have "Show my windows and tabs from last time". Please ignore my question if you're already aware of this issue. Thanks.

Your previous tabs will not re-open or be available to re-open when starting Firefox if:
*your previous session was in Private Browsing mode; see --> http://support.mozilla.org/en-US/kb/Private+Browsing
*you use Clear Recent History (''Firefox button > History > Clear Recent History'' or ''Tools > Clear Recent History''); see --> https://support.mozilla.org/en-US/kb/Clear%20Recent%20History#w_how-do-i-clear-my-history
*you clear History automatically when closing Firefox; see --> https://support.mozilla.org/en-US/kb/Clear%20Recent%20History#w_how-do-i-make-firefox-clear-my-history-automatically
NOTE: Your third-party Plugins (Add-ons > Plugins) are not in the "Application Basics" (Troubleshooting Information) in the "More system details" of your original post. Third-party Plugins are categorized separately in "Installed Plugins" under "More system details". You should review but not change the Plugins as detected automatically by the software on this forum when posting a question.
If you problem still exists after checking the above, the problem could be caused by one or more of your Extensions or Plugins:
*See --> [http://support.mozilla.org/en-US/kb/Troubleshooting+extensions+and+themes Troubleshooting extensions and themes]
*See --> [http://support.mozilla.org/en-US/kb/Troubleshooting+plugins Troubleshooting plugins]
*See --> [http://support.mozilla.org/en-US/kb/Basic+Troubleshooting Basic Troubleshooting]
'''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.'''

Is it possible to ask Siri a question in English and have it respond in another language?

Is it possible to ask Siri a question in English and have it respond in another language?

Not that I'm aware of (yet!) but who knows what Apple will develop for Siri

Question re: MapViewer and Network Model functions

Hi all,
Quick question re: MapViewer and it's support for the Network Model and the shortest-path functions. If I create a base map with a network theme based on my (large) network, and then use a jdbc_network_query on the same network to do some shortest path analysis will MapViewer use the (hopefully) cached copy of the Network to calculate the shortest path? i.e can I expect good response times once the cache is warmed up?
Thanks,
Steve

Hi Steve,
MapViewer uses the Network Java library to run the shortest path algorithm. This library is independent of the MapViewer cache, and also not thread safe. So for now the network is always loaded. The load time may be reduced if the request has a MBR, but it is not the ideal solution. There is a working going on, and we hope to avoid this load in future versions.
Thanks.

2 question about GPU and Lens correction ,cs5

Hi
i have 2 questions about Gpu and lens correction in Cs5
1)Filter->lens correction->search online
i get often and almost every connection time out at the first click on search online , at the second click i get no online profile
is it normal?
2) question is about Gpu
it run faster , but talking about ajustament layer
like saturation or vibrance for example
i found with the gpu on , a light slow refresh compared with gpu off
i have set cache levels 6 ,history 20
i guess are the defaul
well i add a saturation layer and move the saturation slide ,increase o decrease saturation
with Gpu Off , the changes are immedially , i mean i can see in real time the increase o decrease of saturation
with Gpu On it takes a few(very few) time more
again is normal ?
don't be angry , i'm going to buy cs5 and i'm unsecure ... the price make a big role
thanks

For what it's worth, I also see a timeout on the first [ Search Online ] click, after about half a minute delay. Second click turns up results immediately. This happens each time Lens Correction is started, even without restarting Photoshop, and in both 32 and 64 bit versions. Also note that I started with one profile listed by default (though from the wrong camera) for my 40D with 28-135 zoom.
I alsow noticed that I was seeing progress bar activity in the Lens Correction dialog while I was typing this (even though Lens Correction was NOT the active window) every time I hit the 'L' key. Strange.
Windows 7 x64.
-Noel

MSE 7.4 Base Location Services and Context Aware Licences?

Hi! I have a question for MSE Base Location Services and Context Aware Licences. Do I need to add Base Location Services and Context Aware Licences in L-MSE-PAK or just enough Base Location Services Licences? What is the difference in these licenses?
I know that the Base Location Services license is determined by the number of access points, and Context Aware license is determined by the number of devices.
Please help me with this issue.

OK, for example, a customer bought a Context Aware license. Can he activate it in MSE 7.4 or need to install MSE 7.3 with Context Aware license and then upgrade to MSE 7.4?

Hey, I just installed ML on my OCZ Octane SSD, everything went ok, However, it got stuck while rebooting and now I can only see flashing question mark icon and ML won't boot at all. Only in safe mode...

Hey, I just installed ML on my OCZ Octane SSD, everything went ok, However, it got stuck while rebooting and now I can only see flashing question mark icon and ML won't boot at all. Only in safe mode...

It looks like ocz is aware of the issue and trying to address it via firmware:
http://www.ocztechnologyforum.com/forum/showthread.php?103700-Mountain-Lion-and- OCZ-Octane-Petrol-and-Octane-S2-SSD-s
It's a shame because apple is clearly the party that changed something.

Question on clustering and J2EE Environment Entries

Does anyone know if changes made through the admin server console to J2EE
          environment entries are propagated to the managed servers without
          redeploying the entire app. I can find a reference similar to this for
          things in the config.xml which states they are propagated in memory (in most
          cases) and can optionally be written permanently to the confg.xml file. I
          can't find a reference that tells me how/what is done for J2EE environment
          values.
          If this is not possible, how does one do dynamic configuration setting for a
          J2EE application in a clustered environment?
          Kent


What I'm talking about is the environment entries that are set in the web
          application deployment descriptor (web.xml) from the admin server console.
          You go to a specific web-app in the console and then click on "edit web
          application deployment descriptor". From there (towards the bottom of the
          tree on the left) is Env Entry. You can change Environment Entries in the
          DD. What is unclear is if the values are propagated to the running app
          (in memory). For example, if I have a servlet that reads this environment
          entry and I change it in the admin console is the new value reflected
          (relatively) immediately? It's not entirely clear.
          Since there is an option to "persist" these changes (in the top of the tree)
          that would seem to imply that the changes are propagated to the running
          instances in memory otherwise why would I not want to persist the change?
          On the other hand, I would have also expected a button to let me decide when
          to push the changes so I could control when the managed server know about
          the change (for example, if I had to set more than one property to configure
          something).
          So ... does this make my question clearer? And if so is there any
          documentation the describes this? If not how do people handle configuration
          of a running application in a cluster if it not through DD environment
          entries?
          Kent
          "Cameron Purdy" <[email protected]> wrote in message
          news:[email protected]...
          > > Actually I'm talking about what I would call "environment variables" if
          > this
          > > was unix. I am not talking about files (gifs, html, etc) but rather
          > porpety
          > > settings. It is my understanding that these are call "environment
          > entries"
          > > (but I may remembered the name wrong) and are typed values that can be
          > > looked up vi JNDI.
          >
          > You can programmatically set JNDI entries, and they will usually be
          > propagated (although they are not designed to be reliably replicated).
          > Furthermore, the death of the registering server will cause the death of
          the
          > JNDI entries.
          >
          > I don't know how to set them from the console.
          >
          > 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/
          >
          >
          >
          > "Kent Mitchell" <[email protected]> wrote in message
          > news:[email protected]...
          > >
          >
          >
          >

What is the difference between partition-count and the number of caches?

What is the difference between partition-count and the number of caches in Coherence? Are they same?

Those are totally orthogonal concepts.
For more, look at this thread where I answered your other related questions and explain this, too:
Where can I find the accurate definitions of these terms?
Best regards,
Robert

Question regarding battery and warranty

Hi all! I have a quick question about how and if my warranty applies to my battery. After about a year and a half of ownership (I have the three-year extended warranty), my battery has gone completely down the toilet. It wasn't a problem before, but this year I have to lug my T61p around a lot for lab work. My battery is now rated at... 39.75Wh when it shipped at 84.24Wh. This is a pretty drastic difference. In any case, I don't think that this is covered by warranty, but figured that I'd ask before I drop $180 on a new battery (ouch). And, speaking of, if my suspicions are correct, does anybody know where I might find a 9-cell battery for the T61p? All I'm seeing on Lenovo's website is the one for the N100... which doesn't... match very well. Yaknow.
Thanks a lot!
ThinkPad T61p [June 2008]: 2.5Ghz Penryn Core 2 Duo, 4GB DDR2 RAM, NVidia Quadro FX 570m 256MB, 160GB 7200RPM Fujitsu HDD, 1920x1200 WUXGA Matte LCD, Windows 7 RC1

Is either of these appropriate? I'm wary of the one on Amazon, as there are other (off-brand) batteries that are advertised as being Lenovo ones (though those generally sell for a lower price). The other one just looks like I'll have to call up to buy it.
http://www.amazon.com/Lenovo-43R9255-ThinkPad-Notebook-Battery/dp/B001DX9EKA
http://affordablepcsupply.com/products/IBM/REF/42T4511.html
Thoughts?
ThinkPad T61p [June 2008]: 2.5Ghz Penryn Core 2 Duo, 4GB DDR2 RAM, NVidia Quadro FX 570m 256MB, 160GB 7200RPM Fujitsu HDD, 1920x1200 WUXGA Matte LCD, Windows 7 RC1

Questions on InitialContext and replica-aware stub caching

Similar Messages

Maybe you are looking for