Persistent Session Tracking

VTAM® Persistent Session Tracking is provided for both single-node persistent sessions (SNPS), and multinode persistent sessions (MNPS).

The level of VTAM persistent session support desired for IMS is specified on the APPL definition statement using the PERSIST=MULTI|SINGLE parameter.

VTAM SNPSs have the following characteristics:

Reconnect must be on the same CPC as the original IMS.
Only IMS failures and reconnects are supported.

VTAM MNPSs have the following characteristics:

Reconnect may be on another CPC in an IMSplex.
IMS, VTAM, z/OS®, and CPC failures and reconnects are supported.

If you use VTAM MNPS, keep in mind that VTAM end nodes must be running in an APPN/HPR (High Performance Routing) network environment. In addition, all VTAM instances must be connected to a Parallel Sysplex® coupling facility using the ISTMNPS structure.

APPC Persistent session support is provided by APPC/MVS. However, APPC conversations are not automatically restarted following an outage.