0 Replies Latest reply: Aug 29, 2013 10:54 AM by Tim Vincent RSS

    Usage and monitoring of semaphores

    Tim Vincent

      Dear Experts,

       

      My application (which happens to be the TimesTen In-memory database) uses semaphores to manage connections. I have configured /etc/project as follows:

      cat /etc/project

      system:0::::

      user.root:1::::

      noproject:2::::

      user.timesten:100::timesten::process.max-sem-nsems=(priv,4096,deny);project.max-shm-memory=(priv,2147483648000,deny)

      default:3::::

      group.staff:10::::

       

      This was modified as follows:

      projmod -s -K "process.max-sem-nsems=(priv,8192,deny)" user.timesten

      newtask -p timesten -c $$

       

      Then in a new terminal I restarted my timesten daemon

       

      However I seem to only be able to get 455 semaphores allocated, if I ask for more I get an 'out of semaphores' error.

       

      So my questions are:

      1. How can I see who else is using the semaphores in the system? ipcs -a shows no significant usage.

      2. If there are plenty free what am I not doing right so that my program (timesten) picks up the value of 4096 for the maximum number of semaphores that it's allowed?

       

      Thanks in advance

       

      Tim