Understanding Polling and Metric Collection
The PowerMax Integration makes frequent REST API calls to determine when Unisphere for PowerMax has completed statistics data collection from the storage arrays. As soon as the Unisphere management tool finishes collection, IO captures the collected data to generate metrics for the PowerMax Integration.
The Dell EMC PowerMax statistics are generated at preconfigured 5-minute intervals. This PowerMax setting is not configurable.
However, you can set a polling interval in IO that is longer than 5 minutes. If the poll interval is longer than 5 minutes, then during metric collection the data from the previous poll interval is requested at 5-minute granularity. For example, if your poll interval is 1 hour, during collection IO requests the last hour's worth of data at 5-minute granularity. In this example, IO would publish 12 data points, 1 data point for every 5 minutes, after the poll interval completes. This approach allows for metric collection to be spread out over a longer period of time and to be done with fewer requests, thus reducing the impact on the Unisphere system being monitored.
Important
When IO logs the data from Unisphere for PowerMax, it uses the timestamp provided by Unisphere. If the clock on Unisphere is not accurate, then the data might be logged against an inaccurate time, or the data might be dropped altogether.