Cascading global transactions from IMS TM Resource Adapter to IMS systems on different z/OS images

IMS Connect can cascade global (XA) transactions that are submitted on a TCP/IP connection by the IMS TM Resource Adapter to IMS TM systems that are running on different z/OS® images (LPARs).

By default, support for cascading global transactions from the IMS TM resource adapter to IMS systems on different LPARs is disabled. Support for cascading transactions is enabled by specifying the CASCADE parameter in either the definition of the data store connection or the definition of the IMS Connect system configuration.

Performance for global transactions is best when IMS and IMS Connect are running on the same LPAR, so unless performance is not a primary concern, cascade global transactions across LPARs only temporarily as failover protection for when an IMS system that is on the same LPAR as IMS Connect is unavailable.

You can enable IMS Connect support for cascading global transactions to IMS TM data stores that are located on different LPARs in any of the following ways:

Procedure

  1. Set the IMS Connect system default support by either:
    • Issuing the IMS type-2 command UPDATE IMSCON TYPE(CONFIG) SET(CASCADE(ON))
    • Specifying CASCADE=Y in the HWS configuration statement in the HWSCFGxx member of the IMS PROCLIB data set
  2. Set the support option for an individual data store connection in any of the following ways:
    • Issuing the IMS type-2 command CREATE IMSCON TYPE(DATASTORE) SET(CASCADE(ON))
    • Issuing the IMS type-2 command UPDATE IMSCON TYPE(DATASTORE) SET(CASCADE(ON))
    • Specifying CASCADE=Y in the DATASTORE configuration statement in the HWSCFGxx member of the IMS PROCLIB data set
  3. If you updated an existing data store connection, restart the data store connection after the CASCADE option is set.