Using the QueryPerf Method as a Raw Data Feed

The
QueryPerf
method can operate as a raw data feed that bypasses the vCenter database and instead retrieves performance data from an ESXi host. You can use a raw data feed to obtain real-time instance data associated with 20-second interval collection and aggregate data associated with the 5-minute intervals.
You can use a raw data feed on vCenter Server 2.5 and later.
Performance Interval
Description
20-second
ESXi servers collect data for each performance counter every 20 seconds and maintain that data for an hour. When you specify a 20-second interval in the query specification for the
QueryPerf
method (
PerfQuerySpec.intervalId
), the method operates as a raw data feed. The Server ignores the historical interval collection levels and retrieves data for all of the requested counters from the ESXi servers. When you send a query for 20-second instance data, the server returns the most recent data collected for the 20-second interval. The server does not perform additional, unscheduled data collection to satisfy the query.
5-minute
ESXi servers aggregate performance data according to the system-defined performance interval which specifies data collection every 300 seconds. To use a raw data feed for this data, specify the following
PerfQuerySpec
properties in the call to the
QueryPerf
method.
  • intervalId
    – Specify 300 seconds to match the system-defined performance interval.
  • startTime
    /
    endTime
    – Specify time values within the last 30 minutes of the current time. The
    QueryPerf
    method checks the performance interval collection level on the vCenter Server. The method returns aggregated statistics for performance counters that specify a collection level (
    PerfCounterInfo
    .
    level
    ) at or below the vCenter Server performance interval for the 300 second sampling period (
    PerfInterval
    .
    level
    ). For example, if the vCenter Server performance interval is set to level one, and your query specification requests only performance counters that specify level four, the
    QueryPerf
    method will not return any data.