Sync point and response requirements

In order to maintain integrity and recoverability of this queue data set, IMS requires that each recoverable input and output message establish a sync point between both half sessions before continuing the flow. This allows both half session sync-point managers to commit or back out resources in synchronism.

The sync point facility for ISC redefines and separates the DR1 and DR2 requests and responses. The DR2 requests and responses are known as sync-point requests and responses and are functionally independent from those associated with DR1.