Changing resource usage thresholds

Each resource has a fixed capacity, for example CPU cores. If PEs are placed on a resource that needs more CPU processing power than what is available, the resource becomes overloaded and will have poor performance. You can use resource usage thresholds to identify PE load balancing recommendations or, together with the resourceLoadProtectionEnabled instance property, to directly protect resources from being overloaded.

Resource usage thresholds also enable Streams to analyze usage and provide recommendations for PEs restart requests.

It is recommended to view the metrics for CPU utilization, memory utilization, and network bandwidth utilization, and then set resource usage thresholds for their corresponding properties.

About this task

You can change the resource thresholds in Streams Console or with streamtool commands. The following example uses streamtool commands.

Procedure

  1. View the current metrics for the resource by running the streamtool capturestate command. Look for the values of these metrics under the <host> element:
    • cpuUtilization
    • memoryUtilization
    • networkUtilization

    Example command:

    streamtool capturestate --select hosts=metrics

    Example output:

    …
    <metric name="cpuUtilization" lastChangeObserved="1504302827" userDefined="false">
      <metricValue xsi:type="streams:longType" value="58"/>
    </metric>
…
    <metric name="memoryUtilization" lastChangeObserved="1504302827" userDefined="false">
      <metricValue xsi:type="streams:longType" value="76"/>
    </metric>
   …
    <metric name="networkUtilization" lastChangeObserved="1504302827" userDefined="false">
      <metricValue xsi:type="streams:longType" value="15"/>
    </metric>
…

    The values for each metric are percentages of utilization.

    Note: Teracloud® Streams assumes that the utilization metrics of all resources are independent. It does not consider whether resources share physical hardware.
  2. Set the resourceLoadProtectionEnabled instance property.

    Example command:

    streamtool setproperty instance.resourceLoadProtectionEnabled=true
  3. Modify the instances properties for the threshold that you want to change. These properties are dynamic. The threshold properties apply to the domain unless you specify an instance.
    • resourceCpuUsageUpperThreshold
    • resourceCpuUsageLowerThreshold
    • resourceMemoryUsageUpperThreshold
    • resourceMemoryUsageLowerThreshold
    • resourceNetworkBandwidthUsageUpperThreshold
    • resourceNetworkBandwidthUsageLowerThreshold

    Example command: 

    streamtool setproperty instance.resourceCpuUsageUpperThreshold=30 instance.resourceCpuUsageLowerThreshold=70

    For a description of the threshold properties, run the streamtool man properties command.