A job or TP system that requires ATM services must execute alongside an ATM transaction manager, executing in the same system and under the same Adabas SVC or ID table.

An ATM transaction manager runs as a service within an Adabas System Coordinator (SYSCO) daemon. It is therefore implicitly associated with the same Adabas System Coordinator (COR) group as the SYSCO daemon and makes use of services provided by the SYSCO daemon.

A System Coordinator group is a collection of System Coordinator daemons that communicate and inter-operate with each other across coupling facility or Entire Net-Work connections. Currently, on IBM systems, every daemon in a group must execute under the same Adabas SVC. This means that the daemons execute on different logical partitions (LPARs). An ATM transaction manager can execute within each of these daemons.

If there is only one SYSCO daemon in the COR group, there can only be one ATM transaction manager. This transaction manager will provide full support for global transactions that change DTP=RM databases executing under the same Adabas SVC or ID table. If a transaction changes any remote databases – that is, databases that execute in a different network node – these databases will be treated as if they were running with DTP=NO.

If you need to execute transactions that change DTP=RM databases across several network nodes, you will need to define a COR group that encompasses all of these network nodes, and run a SYSCO daemon and an ATM transaction manager in each node. The COR group effectively defines a network of ATM transaction managers that will cooperate in coordinating transactions that change DTP=RM databases across the corresponding network nodes. If a transaction changes any DTP=RM databases that execute in a network node that is not included in the COR group, these databases will be treated as if they were running with DTP=NO.

If appropriate, you could simply define one COR group that includes all network nodes. In this case, all the ATM managers in the network will interact, and will provide full transaction coordination across all DTP=RM databases in the network.