Multiple consumers of the same Queue

In the past my use of JMS queues has been limited to a single message producer and a single consumer. I am now looking at having multiple copies of the same consumer running for load balancing and failover purposes, and this leads me to what I think is a basic question. BTW, we're running OpenMQ 4.4u1.
I have messages being produced and saved in a single queue.
I then have a consumer program whose logic is something like this:
1. Create session with no transaction and CLIENT_ACKNOWLEDGE.
2. Receive message from queue.
3. Do some processing with message. Repeat processing attempts multiple times, if needed, until successful.
4. Once processing is successful, acknowledge message.
Assume that I am running multiple copies of the consumer in separate JVMs (or on separate servers, for that matter).
Here are my related questions.
1. If step 3 takes a long time (e.g., several minutes) can I be sure that only one instance of the consumer will receive the message?
2. If a consumer is in step 3 and a catastrophic failure occurs (e.g., the JVM or server it is running on crashes) the message will never be acknowledged, but the session will not be shut down in an orderly fashion, either. Will the message that was received but never acknowledged eventually be delivered to another copy of the consumer?
3. If step three takes a very long time (hours or days, rather than minutes), will the broker misinterpret this as a failure of the consumer and deliver the same message to another one of the consumers?
Thank you for reading and/or responding to this question.
Bill

1. If step 3 takes a long time (e.g., several minutes) can I be sure that only one instance of the consumer will receive the message?A queue message will only be delivered and consumed by 1 consumer.
2. If a consumer is in step 3 and a catastrophic failure occurs (e.g., the JVM or server it is running on crashes) the message will never be acknowledged, but the session will not be shut down in an orderly fashion, either. Will the message that was received but never acknowledged eventually be delivered to another copy of the consumer?Yes.
3. If step three takes a very long time (hours or days, rather than minutes), will the broker misinterpret this as a failure of the consumer and deliver the same message to another one of the consumers?No, as long as the consumer's Session or Connection are intact

Similar Messages

  • Different / multiple senders to the same EOIO queue name.

    Hello,
    I'd like to know if it is possible to send from different senders, different messages to different receivers but using always same EOIO queue?
    Scenarios are:
    1) SOAP SENDER -> PI ->  SOAP RECEIVER A
    2) IDOC SENDER -> PI -> SOAP RECEIVER B
    3) PROXY ABAP -> SOAP RECEIVER C.
    All messages need to be processed by receivers in the same order they were sent from the different senders.
    How this scenario should be implemented?
    Thanks in advance.

    Hi Michal. Thanks for response!
    As far as I know,
    1- Proxy Sender adds a prefix by defaul. Is it posible to change this behaviour?
    2- By Following note 856597, I understand that you can set your own queue name in parameter &QueueId=xxxxxxxxxxxxxxxx. So there should be no problem.
    3- In Idoc Adapter, you can set a queue name by using a Function Module, but I dont know whether this adds or not a prefix. Will it add a prefix to the queue name?
    So, in case I want to use for all this adapters the same queue, then I need to set in the Soap queueId param, and in the Idoc function module, the same queue name that is generated automatically in Proxy Sender (since this is fixed queue name based on Prefix + custom queue suffix).
    4-  Is that true? Can I guarantee that from IDOC I can use same queue as used by Proxy and IDOC won't add a prefix?
    Thanks again.

  • Multiple instances of the same VI running in parallel

    Hi,
    I have a timestamping subVI that looks at a counter channel and applies timestamps. I want to create multiple instances of this subVI (8 to be exact) and have them all run in parallel (looking at 8 different channels). Someone gave me the following advice:
    >>
    Also, in case you want to call multiple instances of the same SubVI, and you want these multiple instances to execute in parallel, you will have to set the SubVI to execute in reentrant mode. Do this by opening the SubVI and going to "Edit >> VI Properties >> Execution" and enable "Reentrant execution".
    <<
    I've tried this but only my second instance (I started simple with only 2 instances) seems to monitor its channel and pass data along to the queue. I've included my code below, I have two signal simulators which simulate singles coming in on channels 2 and 3. I'm using a PCQI 6602 counter/timer card.
    Any help would be greatly appreciated, thanks in advance,
    Chris
    Attachments:
    LabView App (June 28, 2005).zip ‏158 KB

    good news! Your reentrant VI is working and all three instances are running (as execution highlighting clearly shows). The problem is going to be an error that is occuring but you don't see because you are ignoring the error clusters internally in the timer. It looks like at one point it was set to quit if an error occurred. That still needs to be there.
    Always hookup error clusters...
    Mike...
    Certified Professional Instructor
    Certified LabVIEW Architect
    LabVIEW Champion
    "... after all, He's not a tame lion..."
    Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

  • How many instances can access the same queue at the same time ?

    Hi,
    In my application I am cloning a VI n times and these n instances are accessing the same queue. Is there any restriction on this 'n' for successful operation.
    Regards,
    Runjhun

    Runjhun,
    If the accesses are to enqueue data, then no limit (beyond the number of VIs which will fit in memory).  If you are dequeuing, then n =1. Dequeue removes data from the queue and you would have no way to know which of the n VIs got which element from the queue.  Read the deteiled help for the queue functions.  If you need to read the same data in multiple places, you need some other mechanism.
    Please tell us more about your application.  What kind of data and how much data are in the queue? How fast is the data being generated? How long must the data persist (be availabel after it is generated)? Do you need to guarantee that all the VIs get the data?
    Lynn

  • Sharing one iTunes library across multiple accounts on the same Mac

    Hello, I've poked around at some of the posts dealing with sharing one iTunes music library across multiple accounts on the same Mac but it seems like this can only be done if the libary is moved to a shared folder. I realize this can be done but I was trying to share it the way it is described in a post on Apple support (See link below.). That post seemed to imply that you don't have to move the library from its original location (owned by account A, e.g.), rather just make a couple preference changes in the accounts, use fast user switching and voila. That doesn't seem to work. So my question is this: Is the only way to share one iTunes music library across multiple accounts on the same Mac to move it to a shared folder? I'm running 10.4.8 on an Intel iMac. Thanks in advance!
    http://docs.info.apple.com/article.html?artnum=93195

    After reading this and several other related threads, I am becoming thoroughly confused about all of this. I have a situation similar to the one that pokerpal described in the post dated January 7 at 8:06 pm, except that the music files on my system are located on an external hard drive. Everything else is pretty much the same though - I am the admin user (and the main iTunes user and maintainer) and my girlfriend is a standard user who has no music in her own iTunes library. She can see and listen to and make playlists from and sync her iPod with the music in this library from her account, and I can do the same thing, independent of her, from my account. And if I make a change to information within a song, she doesn't see it, and vice versa, and I understand that. What I don't understand is why when I add a song or an album to the music files by importing a CD or downloading something from the iTunes Music Store, she has no way of knowing that unless I tell her, and then she can add it to her library by using the "Add to Library" function. Is there no way of automatically updating her library files to add the new song(s)? We have almost 15,000 songs and videos in that library, and I don't even want to think about what might have to happen if the answer to my question is "no." Interestingly enough, if I put an update to a Word document in the same exact location (on the hard drive), we can update that and pass it back and forth all day - why is that such a difficult task for iTunes to accomplish?
    Sorry I went on so long, but this has been building up for some time, and none of the solutions I've read about here have really been of any help, so I'm a bit frustrated and, as I said at the beginning, confused.
    iMac G5, MacBook   Mac OS X (10.4.8)  

  • How can I have use the same div ID multiple times on the same page?

    Okay so a problem I encounter a lot is that often times I want to use the same div ID several times on the same page. An example of this is when I'm creating table like designs.
    Let's say for instance I create a div ID called 'product-container'. I want to use 'product-container' multiple times on the same page but if I do this it is improper XHTML and will throw errors in any XHTML validator (you are only allowed to use a div ID once on any XHTML page in order for it to be standards compliant).
    Now the first option is that I could define 'product-container' in my CSS style sheet multiple times by doing something like this...
    #product-container {
         width: 300px;
    #product-container-2 {
         width: 300px;
    #product-container-3 {
         width: 300px;
    #product-container-4 {
         width: 300px;
    What you will see there however is that it seems pointless to define the same ID numerous times over (just adding a number on the end) when each ID is the exact same thing and has the exact same attributes.
    Now what I have noticed is that there are some sites out there who manage to have the same ID appear several times in the code but add a number to it just like above. The difference is that they only have one definition for 'product-cointainer' in their CSS document but in their actual XHTML code they have IDs for 'product-container' but with numbers on the end like 2,3,4,5, etc. It's almost as if JavaScript or some other code is automatically appending a number on the end of the ID so the validator won't consider the markup to be invalid, but yet it knows that it's using the same 'product-container' style that is contained in the CSS style sheet.
    I hope I explained this correctly. I'm just hoping to find a way that I can put the same div ID on a page multiple times without having to define it over and over again in my CSS.
    Any help is much appreciated!

    Because it seems like by using a class you can't make this position as 
    well as you can by using an ID. Am I wrong?
    An ID name can be used only one time per page.  A class name can be used multiple times per page.
    .product {
    width: 300px;
    text-align:left;
    color: #FF0000
    border: 2px solid #666;
    Nancy O.
    Alt-Web Design & Publishing
    Web | Graphics | Print | Media  Specialists
    www.alt-web.com/
    www.twitter.com/altweb
    www.alt-web.blogspot.com

  • How to play one clip multiple times at the same time?

    I am writing a little game where a certain sound has to be played quite frequently. I load it as a Clip and play it with
    myClip.setFramePosition(0);
    myClip.loop(0);If the sound has to be played again but is still being played by another event, the setFramePosition() method resets the sound and the first playing instance is cut off.
    A workaround would be that each object that needs to play this sound would get its own copy, but that is not feasible due to heavy memory consumption.
    So here it goes: How can I play a single sound multiple times at the same time? Is that possible?
    Edited by: andrasz on Feb 27, 2009 12:37 AM

    If the sound has to be played again but is still being played by another event, the setFramePosition() method resets the sound and the first playing instance is cut off.
    A workaround would be that each object that needs to play this sound would get its own copy, but that is not feasible due to heavy memory consumption.
    So here it goes: How can I play a single sound multiple times at the same time? Is that possible?Ummmm, if you're using a clip, you'll have to maintain one copy per object that needs to play the sound concurrently. You could keep one master copy, and then create copies of the clip as necessary to play them, and then just dump the copies to decrease memory consumption.
    A second idea would be to write your own Clip class. Esentially, all you would need to do is dump some sound data onto a TargetDataline to play it. It'll handle the buffering and playing at the correct speed itself. If that's all you did, you should be able to dump multiple times from the same instance and play it multiple times.
    Obviously, that's just a theory. In practice, it may not work that way...

  • There are multiple users with the same display name

    Hi,
    We have a user and when she get an item assigned to her she sees the following alert:
    "There are multiple users with the same display name USERNAME and at least one of them does not have read permissions to some of the files"
    Now I looked in the database and when I run the following query with the username:
     SELECT     
         [ProviderDisplayName]  
        ,[DisplayName]  
        ,[HasDisplayName]  
        ,[Domain]  
        ,[AccountName]  
        ,[UniqueUserId]  
        ,[LastSync]  
      FROM [Tfs_Configuration].[dbo].[tbl_Identity] where displayname like '%USERNAME%'  
    Then I get 2 same usernames back, How can I get rid of one of them ? When I access TFS trough the portal I only find 1 occurence of this user.
    We use VS2013 and TFS2013 update 4
    Best regards

    Hi DSW,  
    Thanks for your post.
    In your query result, please check if these two users have the same Account Name. if they are two different Account Name in result, it indicate there’s two users have the same display name in your AD, please check that two users’ information in
    your AD. We suggest change one user’s display name in AD.  
    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
    Click
    HERE to participate the survey.

  • How open multiple responsibilities in the same user login session in R12 ?

    Dear All,
    Can anyone help me to know how to open multiple responsibility in the same user login session in R12 ?
    Thanks..
    Edited by: G-oracle on Sep 18, 2011 11:22 AM

    Can anyone help me to know how to open multiple responsibility in the same user login session in R12 ?What do you mean by open multiple responsibilities in the same session? You can only see the menu of one responsibility at a time, so how to do you expect the application to let you see multiple responsibilities/menus in one session?
    You could open another session and this way you can access more than one responsibility at the same time.
    Thanks,
    Hussein

  • Can you use sync on multiple computers at the same time? ie have someone else logged into your firefox account for you whilst you are also logged in

    I am trying to sign up to something but there is only a short window so was going to ask a friend to sign in at the same time using my account to try to sign up (with my password being saved into my firefox account)

    Hi. Yes, you can use Sync on multiple devices at the same time. I use it to keep my bookmarks in sync across my desktop and Android versions of Firefox.

  • How can I combine multiple variations of the same library?

    While I have become accustomed to the new Library format/function there are still things that boggle my mind.  Case in point is that I now somehow have multiple versions of the same event showing up although I didn't create them.  And there is also a combination of 2 separate events that I just don't understand.  My current main concern/question is how to combine the duplicitous events?:
    At the top you'll see "Perlick" as the Library and "Beer Cooler" as the Event.  Then down below there is the "Perlick 20140502_1515_CDT".  When I opened the media drive that contains the Perlick event I found a total of 3 "extra" libraries with various long titles as the one just listed.  So, my question is can I somehow combine all of this into one, all-inclusive Library and if so, how?
    Thanks in advance...

    Hello There,
    Try and use tcode VT01N.
    Provide the collective shipment there
    and then click on deliveries & select multiple deliveries there.
    Hope it can assist you
    Thanks & Regards
    JP

  • How can multiple files for the same genre be consolidated

    I organize my iTunes files in genre folders for easy access. ITunes creates multiple folders for some genres and allows a single (preferred) genre file for other much larger files. How can I consolidate multiple files with the same genre?

    Thanks. I've done what you selected. The problem is that despite all files being identified with the same genre, iTunes groups some genres in two separate folders. Thus, I have two "Country" folders, for example. More perplexing is that iTunes groups my largest genre folder, "Jazz", in a single folder.

  • How can I save multiple titles under the same DVD?

    I use HandBrake to rip DVD's into iTunes. How can I save multiple titles under the same DVD? For instance, I have a Jimi Hendrix documentary that comes with special features, such as concert performances. I would like to have the main feature and the special features saved in my iTunes under the same title, perhaps as different 'tracks' (kind of like how different songs can be saved under the same album).
    Is there a way for me to do this, or am I chasing phantoms?

    *This response is for iPhoto 11 (v9). If you're using an earlier version, please post back and let us know. Troubleshooting steps are not the same for different versions. To find out which iPhoto you have: iPhoto Menu -> About iPhoto)*
    Duplicate the photo first. (Photos -> Duplicate). This means that you will have multiple copies of the master as well as the edited version.
    If you use versions like this often and wish to have only one master then you can do this with Aperture.
    Regards
    TD

  • Is there a way to delete multiple pictures at the same time from the iphone4s?

    Is there a way to deleter multiple pictures at the same time, from my iphone4s? I know how to delete one at a time. Thanks

    Open your Photos App > Camera Roll > At the top right corner you will see a rectangle with a right arrow, select that. Now you can select as many photos as you want and you can hit the red Delete button on the bottom right.

  • CRVS2010 - open multiple rpts at the same time, like sheets in a xls file ?

    Hi all,
    is that possible to open multiple reports at the same time, like sheets in a excell file ?
    Is that possible create tabs beside the MainReport tab ? or include reports in the Group Tree ? how can I do it ?
    The application is in asp.net with VS2010 and CR2010.
    The reports used to be in excell with three sheets and now we are migrating them to crystal reports, how can I create the report with those three sheets ?
    thanks !
    Subject modified as per the sticky post at the top of this forum; [Crystal Reports for Visual Studio 2010 Beta - read before posting|Crystal Reports for Visual Studio 2010 Beta - read before posting;
    Edited by: Ludek Uher on Aug 31, 2010 7:33 AM

    I'll make the suggestion to the Program Management group.
    You may want to do a post to the [Crystal Reports Design|SAP Crystal Reports; forum and ask them how they's fake that sort of a requirement. E.g.; there may be some way to make this report look the way you want, but it will be best to ask the experts. Don't mention CRVS2010 as they don't support it and most likely you will not get an answer.
    Ludek

Maybe you are looking for