DX Application Performance Management

  • 1.  clamp limit hit when executing JDBC queries

    Posted Jun 21, 2017 10:51 AM

    I was running a series (every 5min) of small JDBC queries against Introscope 10.5 to extract metric data 


    After a few of them, I start getting failures like this :

     

    com.wily.introscope.spec.server.user.LoginFailedException: Workstation connection from Node=Workstation 41288, Address=<x.x.x.x/x.x.x.x:pppp>, Type=socket of user AuthenticatedUserAdmin was rejected since the clamp value of 40 has been reached.

    (I replaced the host/ports with x & p above)

     

    The Workstation number increments on successive calls too.

     

    I was only executing very simple queries following the examples shown here JDBC API - CA Application Performance Management - 10.1 - CA Technologies Documentation 

     

    What do I need to change to avoid hitting this clamp limit ?   Is there some connection/query-pool management I need to be doing better on my query/client side? 

     

    I don't want to just bump the 40 to some higher number, only to hit it again after a few more query iterations

     

    thx

    Rob



  • 2.  Re: clamp limit hit when executing JDBC queries

    Broadcom Employee
    Posted Jun 21, 2017 11:58 AM

    As mentioned in prior posts, we would like to hear from other customers first that have encountered this clamp situation and how they resolved it or added workarounds. Thanks in advance! 



  • 3.  Re: clamp limit hit when executing JDBC queries
    Best Answer

    Posted Jun 22, 2017 08:43 AM

    Being a relative CA APM novice, I wasn't familiar with the 'clamp' terminology. I now realize that the error I was seeing was related to a max number of open concurrent connections.  I'm revisiting our JDBC client to make sure it is properly closing connections.



  • 4.  Re: clamp limit hit when executing JDBC queries

    Broadcom Employee
    Posted Jun 22, 2017 08:47 AM

    Thanks Robert. I will mark this thread as Answered. However, you are welcome to post status updates and follow-up questions if needed. Feel free to contribute to threads of other customers if you can.



  • 5.  Re: clamp limit hit when executing JDBC queries

    Broadcom Employee
    Posted Jun 22, 2017 09:00 AM

    Hello Robert,

     

    Yes, indeed, 40 is max of active workstation:

    apm-events-thresholds-config.xml - CA Application Performance Management - 10.5 - CA Technologies Documentation 

    CA APM Client Requirements - CA Application Performance Management - 10.5 - CA Technologies Documentation 

     

    FYI, if at some point you decide to use APM SQLServer, please note that there is also a clamp for concurrent sql queries, but the clamp is available from the EM properties file, see this KB

    Using the new 10.5 APMSQL Server feature the MOM log shows "AGCSmartstoreControllerImpl: Maximum number of connections r… 

     

    Anyway, I don't see any mention of this property in docops, I will ask doc team to include it.

     

    Regards,

    Sergio



  • 6.  Re: clamp limit hit when executing JDBC queries

    Posted Jun 22, 2017 09:12 AM

    Thanks Sergio,

     

    On our side, wasn't so much that we weren't closing, it was that we

    maintain a pool of connections, which by default was larger than the 40 set

    on CA APM :-).

     

    Anyway, mystery solved and thanks for the help.

     

    and yah, we want to move to APMSQL as soon as possible - we have some

    requirements for compatibility with pre 10.5 versions which is holding us

    back  .. for another while though

     

    Thanks again,

    Rob

     

    On Thu, Jun 22, 2017 at 9:06 AM, Hallett_German <