Aggregated Metrics for Managed System

To provide access to the utilization data for longer duration, the HMC processes the raw metrics and performs data aggregation. The aggregated metrics are retained in the HMC for long duration and the duration is configurable by PCM preferences APIs.

This API is used to retrieve the aggregated metrics for a managed system. To retain the processed performance utilization data for longer duration, they are aggregated. The levels of aggregation are:
  1. Tier 1 roll up: The processed metrics that are collected over 5 minutes form one aggregated metrics sample. The tier 1 metrics are retained for 2 hours.
  2. Tier 2 roll up: The tier 1 metrics are further rolled up to have one sample for 2 hours. The tier 2 metrics are retained for 1 week.
  3. Tier 3 roll up: The tier 2 metrics are further rolled up to have one sample per day. The tier 3 metrics are retained until the retention duration set by preferences API.

In the rolled up data, for example, for the aggregated metrics, the system maintains three values: Average, Minimum, and Maximum of the underlying processed metrics.

Resource

/rest/api/pcm/ManagedSystem/{uuid}/AggregatedMetrics
/rest/api/pcm/ManagedSystem/{uuid}/AggregatedMetrics?StartTS={StartTS}&EndTS={EndTS}&NoOfSamples=
{n}&Feed={feed}
Since: Version 1_1_0
Table 1. Quick properties
Quick property Description Format
StartTS Start timestamp is a mandatory parameter. The API returns available aggregated metrics after the specified time. yyyy-MM-ddTHH:mm:ssZ
EndTS End timestamp is an optional parameter. If specified, the API returns available aggregated metrics on or before the specified time. yyyy-MM-ddTHH:mm:ssZ
NoOfSamples Number of samples is an optional parameter. If specified, the API returns the specified number of aggregated metrics. int > 0
Feed Feed is an optional parameter.
  • bySource: the API returns aggregated metrics for managed system and links to fetch aggregated metrics for its logical partitions.
  • byTier: the API returns consolidated aggregated metrics for managed system and all its logical partitions.
 Specify one of the two values:
  • bySource (default)
  • byTier
Table 2. Supported methods
Method Description Internet media type
GET This API retrieves the aggregated metrics for a managed system. The response is returned as an Atom feed to the consumer. The Atom Feed contains the Atom links to all the aggregated JSON files for the managed system. The Atom link is a web link to the actual JSON file. The content can be retrieved by using the Atom link. application/xml

Response

Successful execution of the request is returned with response code 200. In response the application returns Atom feed and Atom entries. Attributes of the Atom feed are as follows:

  • Id: UUID of the Managed System
  • Updated: Timestamp of the last available Aggregated metrics data

The Atom feed has series of Atom entries. Attributes of the Atom entry follow:

  • Updated: End timestamp of the Aggregated JSON returned
  • Published: Start timestamp of the Aggregated JSON returned
  • Link: Type application/json, Link to the Aggregated JSON data
  • Category: Indicates the metrics category, in this case ManagedSystem
    • Frequency: Indicates metrics aggregation frequency in seconds

The application aggregates data at every aggregation interval and generates snapshots of the managed system utilization. Each snapshot corresponds to an Atom entry.

The metric data is supplied in the JSON format. The following link provides JSON specification for managed system aggregated metrics.