4 Replies Latest reply: Mar 29, 2014 12:56 PM by William64 RSS

    For a single direct connection, the rss size is greatly increased from tt6.0 to tt.11.2, expected?

    William64

      We recently encountered an issue with running size of an application after upgrading to newer version of timesten for solaris.  The application uses direct connections and keeps connections open to each DSN, which we have 6 dns.    While investigating, I noticed the prstat  rss size had increased greatly with the new release.    I've included a table showing the

      SIZE and RSS size for a command line direct connection to each dsn with old and new timesten version.   Is this expected?  If not, what could be wrong?

       

      prstat output
      sizerss
      CallProctt6018027
      tt112247236
      SystemConfgtt6016027
      tt112247236
      SS7tt6011227
      tt112195182
      Emstt6030627
      tt112371361
      DynamicDbtt6011227
      tt112195182
      Subscribertt6026527
      tt112331321
        • 1. Re: For a single direct connection, the rss size is greatly increased from tt6.0 to tt.11.2, expected?
          Chrisjenkins-Oracle

          I don't think this is something we have particularly measured / looked at but it could certainly be true. It isn't any cause for concern. The RSS is just the set of memory pages that are currently mapped into physical memory out of all the memory pages that comprise the process. TimesTen 11.2 has a lot more functionality and many internal differences plus it has a separate PL/SQL segment etc., etc. so it would not surprise me at all if the set of memory pages that are mapped into memory at any moment for a particular workload is larger. Of course, best practice is to lock all the datastore memory into physical RAM using MemoryLock=4 so the actual overall physical memory usage should not really be much different.

           

          Can you post your 6.0 and 11.2 DSN definitions so we can see the parameters? Is your schema identical in 6.0 compared to 11.2? Are the data volumes identical?

           

          Chris

          • 2. Re: For a single direct connection, the rss size is greatly increased from tt6.0 to tt.11.2, expected?
            William64

            The schema had a few differences between the two TT versions. The data in the DSNs between the two releases are also similar.  Most of our lab machines have the same basic configuration. 

             

            The definition for the 6 DSNs are the same except for PERM/TEMP size. 

             

            TT60 DSN definition:

            =====================================

            [SystemConfigurationDir]

            Driver=/opt/SANTone/msc/active/TimesTen/lib/libtten.so

            DataStore=/Santera/db/SystemConfiguration

            AutoCreate=0

            DurableCommits=0

            ExclAccess=0

            LockLevel=0

            PermWarnThreshold=80

            TempWarnThreshold=80

            PermSize=100

            TempSize=30

            ThreadSafe=1

            WaitForConnect=1

            Preallocate=1

            authenticate=0

            MemoryLock=1

            SMPOptLevel=1

            Authenticate=0

            Connections=200

            CkptFrequency=300

             

             

             

             

            TT11.2  DSN definitions

            ====================================

            [SystemConfigurationDir]

            Driver=/opt/SANTone/msc/active/TimesTen/lib/libtten.so

            DataStore=/Database/db/SystemConfiguration

            AutoCreate=0

            DurableCommits=0

            ExclAccess=0

            LockLevel=0

            PermWarnThreshold=80

            TempWarnThreshold=80

            PermSize=100

            TempSize=50

            ThreadSafe=1

            WaitForConnect=1

            Preallocate=1

            MemoryLock=4

            SMPOptLevel=1

            Connections=200

            CkptFrequency=300

            DatabaseCharacterSet=TIMESTEN8

            TypeMode=1

            DuplicateBindMode=1

            • 3. Re: For a single direct connection, the rss size is greatly increased from tt6.0 to tt.11.2, expected?
              Chrisjenkins-Oracle

              Thanks for that. I don't see anything anomalous there. A few comments however:

               

              1.    I'm glad to see you have switched from using MemoryLock=1, which is fairly pointless in most cases, to MemoryLock=4 which is our recommended best practice.

               

              2.     The attributes SMPOptLevel and ThreadSafe were deprecated in 11.2.1 and no longer have any effect (they are only accepted for compatibility purposes). We may remove these attributes in the next release so you would be well advised to remove them from your DSN definitions to avoid problems in the future.

               

              I would say that the increase in RSS size is just down to internal differences between the releases; internally 11.2.2 is hugely different to 6.0. Also, your unspecified schema differences could also be a factor. Is there some reason why you are concerned about this?

               

              Chris

              • 4. Re: For a single direct connection, the rss size is greatly increased from tt6.0 to tt.11.2, expected?
                William64

                We monitor the sizes of our applications.  If the application exceeds the upper limit, the platform process monitor will reset the offending application.   This monitoring was done years ago to keep any application with memory leaks from grabbing all the memory. We have two applications that perform direct connects instead of client/server.  Once of these, the configuration manager, connects to all size DSNs.   On a couple of our lab system, we noticed the cfgmgr was being restarted due to excessive memory.  Further investigation revealed the increase the size.  For now, we've increase the threshold.  

                 

                I suspected it was the additional changes between the two releases that caused the increase.