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What Contention History charts display

On the Dynamic Threshold Event Details page, the Contention History charts display historical performance statistics for the cluster component in contention. You can review the charts to learn about the top victim workloads at the component, the history of utilization or activity for the component, and the history of events for the component.

The selected event is indicated by a red-shaded line that appears in each of the displayed charts. The width of the red line indicates the event duration. The event duration is the time between detection, when the event became new, and the time when the event was last analyzed or, for an obsolete event, when it was resolved.

For active events (new or acknowledged), the charts show 10 days of data prior to the event detection. For obsolete events, the data prior to the event detection is three times the event duration. For example, if an event was new for one day, and then became obsolete, the charts display three days of data before the event detection and two days of data after the event resolution. If there is not enough data before or after the event, the charts display the maximum data available. If an event has a very short duration of less than one hour, six hours of data is displayed before and after the event. The data after the event was resolved is two times the event duration.

Note: Because Unified Manager retains a maximum of 30 days of 5-minute historical performance and event data, if the event is more than 30 days old, no performance data is displayed.

The following charts are displayed:

Top Victim Workloads
Displays the history of response time (latency), in milliseconds per operation (ms/op), for the top victim workloads at the component in contention. The top victims have the highest peak deviation in latency. You can hide and show the statistics for a workload by selecting the check box next to the workload name. You can point to the statistics for a displayed workload to view its latency at a specific point in time.
The latency values displayed in the Top Victim Workloads chart do not match the latency values displayed in the Cluster components breakdown chart on the Performance/Volume Details page. The Top Victim Workloads chart displays the actual latency at the cluster component, while the Cluster components breakdown chart provides a visualization of the amount of time spent at a cluster component. Also, because the Cluster components breakdown chart displays the combined latency values of components of the same type, these values do not match the values in the Top Victim Workloads chart, which shows the latency at the specific component in contention.
Component Usage
Displays the history of utilization, in percent, for the network processing, data processing, and aggregate components or the history of activity, in percent, for the QoS policy group component. The chart is not displayed for the network or interconnect components. You can point to the statistics to view the usage statistics at a specific point in time.
Total Write MBps History
For the MetroCluster Resources component only, shows the total write throughput, in megabytes per second (MBps), for all volume workloads that are being mirrored to the partner cluster in a MetroCluster configuration.
Event History
Displays red-shaded lines to indicate the historic events for the component in contention. For obsolete events, the chart displays events that occurred before the selected event was detected and after it was resolved.