System and method for supporting resource manager (RM) instance awareness in a transactional environment

A system for supporting transaction processing in a transactional environment, comprising:

• a plurality of networked computer systems each comprising one or more microprocessor and memory;
• a plurality of transactional servers operating on said plurality of networked computer systems, wherein said plurality of transactional servers include a plurality of transaction managers;
• a database;
• a plurality of resource manager (RM) instances for managing access to the database;
• a server table stored in a shared memory accessible from said plurality of transactional servers, said server table comprising a server table entry for each of said plurality of transactional servers and an instance identifier for each of said plurality of transactional servers,
• wherein the plurality of transactional server are configured to receive RM instance information indicative of which RM instance of the plurality of RM instances said each of the plurality of transactional servers is currently connected to;
• wherein the plurality of transactional server are configured to save the received instance information into the instance identifier associated with said each of the plurality of transactional servers in said server table in said shared memory accessible from said plurality of transactional servers;
• wherein transactional servers participating in global transactions are configured to access said server table to obtain instance information identifying which of the plurality of transactional servers are connected to which RM instance, and thereby coordinate said global transactions based on said instance information;
• and
• wherein the plurality of transactional servers are configured to update the instance identifier associated with said each of the plurality of transactional servers in said server table in said shared memory in response to changes in connections between said plurality of transactional servers and said plurality of databases.

A non-transitory machine readable storage medium having instructions stored thereon for supporting transaction processing in a transactional system comprising:

• a plurality of transactional servers including a plurality of transaction managers, and a plurality of resource manager (RM) instances for managing access to a plurality of databases, which instructions, when executed, cause the transactional system to perform steps comprising:
• providing a server table in a shared memory accessible from said plurality of transactional servers, said server table comprising a server table entry for each of said plurality of transactional servers and an instance identifier for each of said plurality of transactional servers,
• receiving at each of the plurality of transactional servers RM instance information indicative of which RM instance of the plurality of RM instances said each of the plurality of transactional servers is currently connected to;
• saving the received instance information from each of the plurality of transactional servers into the instance identifier associated with said each of the plurality of transactional servers in said server table in said shared memory accessible from said plurality of transactional servers;
• allowing transactional servers participating in global transactions to access said server table to obtain instance information identifying which of the plurality of transactional servers are connected to which RM instance, and coordinate said global transactions based on said instance information;
• and
• in response to changes in connections between said each of the plurality of transactional servers and said plurality of databases, updating the instance identifiers associated with said each of the plurality of transactional servers in said server table in said shared memory.