$ZONLNRLBK increments every time a process detects a concurrent MUPIP JOURNAL -ONLINE -ROLLBACK.

GT.M initializes $ZONLNRLBK to zero (0) at process startup. GT.M does not permit the SET or NEW commands to modify $ZONLNRLBK.

For more information on online rollback, refer to the -ONLINE qualifier of -ROLLBACK in GT.M Administration and Operations Guide.