Continuous performance monitoring

Continuous monitoring watches system throughput, resource usage (processor, I/Os, and storage), changes to the system, and significant exceptions that might affect system performance.

Procedure

  • Try to continually run classes 1, 3, 4, and 6 of the Db2 statistics trace and classes 1 and 3 of the Db2 accounting trace. For data sharing environments, run class 5 too.
  • In the data that you collect, look for statistics or counts that differ from past records.
  • Pay special attention to peak periods of activity, both of any new application and of the system as a whole
  • Run accounting class 2 as well as class 1 to separate Db2 times from application times.

    Running with CICS® without the open transaction environment (OTE), entails less need to run with accounting class 2. Application and non-Db2 processing take place under the CICS main TCB. Because SQL activity takes place under the SQL TCB, the class 1 and class 2 times are generally close. The CICS attachment work is spread across class 1, class 2, and time spent processing outside of Db2. Class 1 time thus reports on the SQL TCB time and some of the CICS attachment. If you are concerned about class 2 overhead and you run a CICS workload only, you can generally run without turning on accounting class 2.

  • Run accounting class 3 trace for monitoring suspension time in Db2.
  • Run accounting class 7 and 8 if you want to monitor package information.
    Class 10 provides more detailed package information but also has additional CPU and SMF volume overhead.
  • Statistics and accounting information can be very helpful for application and database designers. Consider putting this information into a performance warehouse so that the data can be analyzed more easily by all the personnel who need the information.

    IBM Tivoli® IBM® OMEGAMON® for Db2 Performance Expert on z/OS® Db2 Performance Expert on z/OS includes a performance warehouse that allows you to define, schedule, and run processes that help in monitoring performance trends and tuning.

    The data in the performance warehouse can be accessed by any member of the Db2 family or by any product that supports Distributed Relational Database Architecture (DRDA).