1. Get Started with Performance Tuning
  2. Proactive Database Tuning
  3. Monitoring Real-Time Database Performance
  4. Monitoring Host Activity
  5. Monitoring CPU Utilization

Monitoring CPU Utilization

To address CPU problems, first establish appropriate expectations for the amount of CPU resources your system should be using. You can then determine whether sufficient CPU resources are available and recognize when your system is consuming too many resources. This section describes how to monitor CPU utilization.

To monitor CPU utilization:

  1. Access the hostname page as explained in "Monitoring Host Activity".

  2. From the Host drop-down menu, select Monitoring, and then CPU Details.

    The CPU Details page appears.

    This page contains statistics about CPU utilization, I/O wait times, and load gathered over the last hour. The top 10 processes are listed based on CPU utilization.

  3. Verify the current CPU utilization using the CPU Utilization chart.

    The CPU Utilization chart shows CPU utilization over the last hour and a half. The current value is displayed below the chart. During standard workload hours, the value should not exceed the critical threshold.

  4. Under the graph for CPU Utilization, click the link CPU Utilization.

    This page contains CPU utilization statistics and related alerts generated over the last 24 hours.

    If you notice an unexpected spike in this value that is sustained through normal workload hours, then the CPU performance problem should be investigated.

  5. Return to the CPU Details page. From the Host menu, select Monitoring, and then CPU Details.

  6. Verify the current CPU I/O wait time using the CPU I/O Wait chart.

    The CPU I/O Wait chart shows CPU I/O wait time over the last hour and a half. The current value is displayed below the chart. During normal workload hours, the value of CPU I/O wait should not exceed the warning threshold.

    CPU I/O wait represents the average number of jobs waiting for I/O during an interval.

  7. Under the graph for CPU I/O Wait, click the link CPU I/O Wait.

    The CPU in I/O Wait page appears.

    This page contains CPU I/O wait statistics and related alerts generated over the last 24 hours.

    If you notice an unexpected increase in this value that is sustained through standard workload hours, then a CPU performance problem may exist.

  8. Return to the CPU Details page. From the Host menu, select Monitoring, and then CPU Details.

  9. Verify the current CPU load using the CPU Load chart.

    The CPU Load chart shows the CPU load over the last hour and a half. The current value is displayed below the chart. During standard workload hours, the value of CPU load should not exceed the warning threshold.

    CPU load represents the average number of processes waiting to be scheduled for CPU resources in the previous minute, or the level of CPU contention time over time.

  10. Under the graph for CPU Load, click the link CPU Load.

    The Run Queue Length (5 minute average) page appears.

    This page contains CPU load statistics and related alerts generated over the last 24 hours.

    If you notice an unexpected spike in this value that is sustained through normal workload hours, then a CPU performance problem might exist.

  11. Return to the CPU Details page. From the Host menu, select Monitoring, and then CPU Details.

  12. Review the Top 10 Processes (ordered by CPU) table.

    If a process is consuming too much of the CPU utilization percentage, then investigate that process.

  13. If a CPU performance problem is identified, then you can try to resolve the issue by doing the following:

    • Use Oracle Database Resource Manager to reduce the impact of peak-load-use patterns by prioritizing CPU resource allocation

    • Avoid running too many processes that use a large amount of CPU

    • Increase hardware capacity, including changing the system architecture

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