Accessing performance data using the RMF Distributed Data Server
With the two flavors of the Distributed Data Server (GPMSERVE and GPM4CIM, also known as RMF XP), RMF offers a solution to monitor the performance of systems in heterogeneous environments. Application programs that want to retrieve performance data can use the HTTP API of the Distributed Data Server (DDS).
- For systems in a z/OS environment, the DDS GPMSERVE component gathers data from the RMF instances running on the sysplex members. An application program can request selected performance metrics or complete reports from the DDS. Thus, exploiters of this HTTP API have instant access to a great variety of z/OS performance metrics, including short-term information as well as long-term historical data.
- The HTTP API of the DDS can also
serve requests for AIX® and Linux® performance data, which are directed against an active GPM4CIM instance. RMF XP supports
the following operating systems:
- AIX on System p
- Linux on System x
- Linux on System z®
GPM4CIM is the core component of RMF XP. For detailed information about RMF XP, see z/OS Resource Measurement Facility User's Guide.

Figure 1 illustrates how to use the DDS HTTP API in a z/OS environment, where requests must be sent to the GPMSERVE component of the DDS. Likewise, in a heterogeneous AIX/Linux environment, you send your HTTP request to the corresponding GPM4CIM instance of the DDS. Each instance of GPMSERVE or GPM4CIM uses a unique port to listen for incoming requests. The returned XML documents have the same syntax for both Distributed Data Server components.
This information unit describes the format and usage of DDS requests as well as the format of the returned XML documents in the following topics: