cpu_idle - Processor idle time monitor element

Usage

• This measurement represents the aggregate for all processors on the system.
• On AIX, this metric is reported for the workload partition (WPAR) and the logical partition (LPAR) on which the DB2® server is running.
• You can use this monitor element along with the related processor timer elements to calculate processor utilization for a specific time interval on the host system. To calculate processor utilization as a percentage, perform the following steps:
  1. Use the ENV_GET_SYSTEM_RESOURCES function at the beginning to the time interval to retrieve the values for the following metrics:
     • cpu_user_t1 = cpu_user
     • cpu_system_t1 = cpu_system
     • cpu_idle_t1 = cpu_idle
     • cpu_wait_t1 = cpu_wait
  2. Repeat the preceding step to determine the timestamps for the same metrics at the end of the time interval for which you want to calculate processor utilization:
     • cpu_user_t2 = cpu_user
     • cpu_system_t2 = cpu_system
     • cpu_idle_t2 = cpu_idle
     • cpu_iowait_t2 = cpu_iowait
  3. Calculate processor utilization using the following formula:

           (cpu_systemt2 - cpu_systemt1) + (cpu_usert2 - cpu_usert1)
     100 × ----------------------------------------------------------
           (cpu_systemt2 - cpu_systemt1) + (cpu_usert2 - cpu_usert1) +
           (cpu_idlet2 - cpu_idlet1) + (cpu_iowaitt2 - cpu_iowaitt1)