Connecting as a resource manager

A resource manager is an application you can write and associate with a log stream to manage resources and processing for a log stream.

For example, via the resource manager user exit, a resource manager might be notified of a write or delete request issued against a log stream. The resource manager can then perform further processing to accept, reject, or override the delete request with a different log block identifier. A resource manager application can be helpful to perform any management functions on behalf of a log stream.

Before a resource manager can connect to a log stream, the name of the resource manager must be specified in the log stream definition in the LOGR couple data set. You can specify one resource manager name for a log stream in the log stream definition. See z/OS MVS Setting Up a Sysplex for setting up a log stream definition in the LOGR couple data set.

If you specify a resource manager name for a log stream in the LOGR policy, the resource manager specified must connect to the log stream. If the resource manager does not connect, system logger will not process any IXGDELET requests to delete log data. This is so that the resource manager will not miss any information about deletes issued against the log stream.

The resource manager connects to the log stream it manages using the RMNAME, RMEXIT, RMDATA, and RMEVENTS parameters on the IXGCONN service. You must be running in supervisor state and a system key to use these parameters. The connect request must be issued from the resource manager address space. The resource manager address space must be non-swappable with an authorization index (AX) value of 1, or all invocations of the resource manager exit will fail.

Note that only one resource manager can connect to a log stream from a given system. The resource manager can connect to multiple log streams.

Use the resource manager parameters as follows:

RMNAME: Specifies the name of the resource manager program connecting to the log stream. This is the same name specified on the RMNAME parameter in the LOGR couple data set log stream definition.
RMEXIT: Specifies the name of a resource manager user exit. The resource manager exit is called when write or delete requests (as specified on the RMEVENTS parameter) are issued against the log stream that the resource manager manages. The RMEXIT keyword is required with RMNAME. For information on the resource manager exit, see Coding a resource manager exit for IXGCONN.
RMEVENTS: Specifies that write or delete requests issued against the log stream are to trigger the resource manager exit. RMEVENTS is required with RMNAME. You can specify RMEVENTS=LBWRITE, RMEVENTS=LBDELETE, or RMEVENTS=(LBWRITE,LBDELETE).
RMDATA: Specifies user-defined data to the resource manager. This data is then passed to the resource manager user exit when the exit is called.
RMDATA is required with RMNAME.