An ATM daemon executes alongside an Adabas System Coordinator (SYSCO) daemon, under the same Adabas SVC or ID table. It is therefore implicitly associated with the same Adabas System Coordinator (COR) group as the SYSCO daemon. It makes use of services provided by the local 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 daemon can execute in each of the LPARs, under the same SVC as the COR daemon.
If there is only one SYSCO daemon in the COR group, there can only be one
ATM daemon. This ATM daemon 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 daemon in each node. The COR group effectively
defines a network of ATM daemons 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 daemons in the network will interact,
and will provide full transaction coordination across all
DTP=RM databases in the network.
