The TM, together with the XA Interface, establishes connections between applications and RMs in several steps.
Establishing connections in a CICS environment
When the CICS region starts up, it issues an XA open call to each LRM configured in an XAD, using the information contained in each open string.
The CICS region passes to the XA Interface library the open string associated with each stanza. The open string contains the LRM name, the user name, and the password.
The XA Interface looks up the LRM name in the Sybase XA configuration file and matches it to an actual RM name, that is, an actual physical Adaptive Server. The RM name matches an entry in the Adaptive Server interfaces file.
The XA Interface establishes one connection to an Adaptive Server for each LRM entry. The XA Interface confers on any connection the pre-connection properties and capabilities configured for the LRM.
Establishing connections in an Encina environment
An application issues a mon_RegisterRmi function, thereby requesting use of an LRM.
Using information contained in an open string, the TM issues an XA open call to the LRM (configured in the monadmin create rm command) whose name matches that issued in step 1, above.
The TM passes the open string associated with each monadmin create rm command to the XA Interface. The open string contains the LRM name.
The XA Interface looks up the LRM name in the Sybase XA configuration file and matches it to an actual RM name—that is, to an actual physical Adaptive Server. The RM name matches an entry in the Adaptive Server interfaces file.
The XA Interface establishes one logical connection to an Adaptive Server for each LRM entry. The XA Interface confers on any connection the pre-connection properties and capabilities configured for the LRM.
Establishing connections in a TUXEDO environment
The application uses the LRM specified in the UBBCONFIG file to reference the logical connection for a branch of a global transaction. In using the LRM name, the application implicitly requests and establishes an LRM.
The transaction manager passes the appropriate open string to the XA Interface through the LRM whose name matches the one issued in step 1. The XA Interface uses the LRM name, the user name, and the password.
The XA Interface looks in the xa_config file to find an association between the LRM name and Adaptive Server. The Adaptive Server name matches an entry in the interfaces file where its network information is kept.
The XA Interface establishes one logical connection to an Adaptive Server for each LRM entry. The XA Interface confers on any connection the pre-connection properties and capabilities configured for the LRM.
