3 Replies Latest reply: Nov 12, 2012 7:33 AM by 856103 RSS

    Kernel Parameter Impact on Timesten Performance

    856103
      Hi,

      Can you please guide me on the impact of certain kernel/hardware parameters on Timesten performance :

      kernel.shmmax
      kernel.shmall
      kernel.msgmni
      kernel.shmmni

      I have two servers with the same Timesten DSN configuration. A particular process takes 15 ms on one server (Server A) and 5 ms (Server B) on the other. The Timesten and linux versions on both are similar. Memory is the same (32 GB). DSN parameters are exactly same as well.


      On comparing cpuinfo and sysctl.conf i found the following differences :
      Server A
      
      cpuinfo
      processor     : 23
      vendor_id     : GenuineIntel
      cpu family     : 6
      model          : 46
      model name     : Intel(R) Xeon(R) CPU E7540 @ 2.00GHz
      stepping     : 6
      cpu MHz          : 1064.000
      cache size     : 18432 KB
      cpu cores     : 6
      
      sysctl.conf
      
      kernel.shmmax = 68719476736
      kernel.shmall = 4294967296
      kernel.msgmni=1000
      net.core.wmem_max=4194304
      Server B
      
      cpuinfo
      processor     : 15
      vendor_id     : GenuineIntel
      cpu family     : 6
      model          : 44
      model name     : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz
      stepping     : 2
      cpu MHz          : 2400.000
      cache size     : 12288 KB
      cpu cores     : 4
      
      sysctl.conf
      
      kernel.shmmax = 17179869184
      kernel.shmall = 17179869184
      kernel.msgmni=100000
      kernel.shmmni = 4096
      net.core.wmem_max = 1048576
      Timesten Version - TimesTen Release 11.2.1.8.0 (64 bit Linux/x86_64)
      DSN Parameters :
      
      Driver=/application/matrix/TimesTen/matrix/lib/libtten.so
      DataStore=/application/matrix/TimesTen/DAIWAPRODV7_DSN_datastore/DAIWAPRODV7_DSN_DS_DIR
      LogDir=/logs_timeten/DAIWAPRODV7_DSN_logdir
      PermSize=8000
      TempSize=250
      PLSQL=1
      DatabaseCharacterSet=WE8MSWIN1252
      OracleNetServiceName=fodbprod
      Connections=500
      PassThrough=0
      SQLQueryTimeout=250
      LogBufMB=1024
      LogFileSize=1024
      LogPurge=1
      PLSQL_MEMORY_SIZE=1000
      PLSQL_CONN_MEM_LIMIT=2000
      Regards,
      Karan
        • 1. Re: Kernel Parameter Impact on Timesten Performance
          Chrisjenkins-Oracle
          Hi Karan,

          Those kernel parameters won't affect performance. They will simply affect how much shared memory, messages and semaphores are configured in the kernel. This may affect whether a particular TimesTen datastore can be loaded into memory or not but if it loads then they have no real effect on performance.

          The difference in performance is due to this:

          model name     : Intel(R) Xeon(R) CPU E7540 @ *2.00GHz*
          stepping     : 6
          cpu MHz          : *1064.000*
          cache size     : 18432 KB
          cpu cores     : 6

          versus this:

          model name     : Intel(R) Xeon(R) CPU E5620 @ *2.40GHz*
          stepping     : 2
          cpu MHz          : *2400.000*
          cache size     : 12288 KB
          cpu cores     : 4

          The second machine has a significantly faster CPU...

          Chris

          Edited by: ChrisJenkins on Nov 12, 2012 12:01 PM
          • 2. Re: Kernel Parameter Impact on Timesten Performance
            Tim Vincent
            Hi Karan,

            The OS kernel parameters don't really have an impact on performance, they are more around OS memory resources management.

            TimesTen is very 'lightweight' in terms of the CPU cycles used to access data. Therefore as a generalisation on a single thread we typically see the faster the CPU the faster TimesTen will go. As below Server B has a faster CPU, so would expect a single thread to be faster here than on Server A.

            Tim
            • 3. Re: Kernel Parameter Impact on Timesten Performance
              856103
              Thanks Chris/Tim ..