Conference clusta::acms

4141.0. "ACMS with DECdtm in mixed Decnet environments" by OHMARY::HALL (Bill Hall - ACMS Engineering - ZKO2-2) Thu Apr 03 1997 00:03

	ACMS has always supported DECnet Phase IV.  With the
	advent of DECnet/OSI (now called DECnet-Plus), this 
	has posed a few problems, but as long as NSP protocols
	are used (i.e. Phase IV), ACMS does not know what
	environment it is running in, as long as node names
	are 6 characters or less.

	A problem has recently surfaced where a customer network
	contained both DECnet Phase IV and DECnet/OSI systems.
	The problem occurred when attempting to start a 
	distributed transaction and then using an agent in a 
	server, starting a task on a remote system, passing the
	TID and running a remote, composable task.

	As part of the messages that are sent between systems,
	the 'commit domain' is sent when ACMS realizes that this
	is a distributed, 2PC transaction.  The remote system
	translates the logical SYS$DECDTM_NODE_NAME and sends
	this translation to the local system.  On a Phase IV system,
	SYS$DECDTM_NODE_NAME contains the Phase IV node name, like
	AMAMA.  On a DECnet/OSI system, this logical contains
	LOCAL:.AMAMA when a local database is used, or DEC:.ZKO.AMAMA
	when DNS is used.
	
	When a Phase IV system talks to a DECnet/OSI system (in 
	ACMS terms), this translation is used on the local system and
	results in an error 'remote system is unknown'.  DECnet
	Phase IV cannot use a node that contains LOCAL: or
	something like DEC:...
	
	The workaround is to redefine SYS$DECDTM_NODE_NAME to be
	Phase IV style node name, or define an application logical
	name with the same translation.

	Unfortunately, this has occurred too late in the cycle, and
	the ACMS V4.2 release notes will not contain this restriction.