You can configure CICS® Transaction
Gateway to benefit from XA transactionality. XA transactionality provides
support for two-phase commit transactions and allows CICS Transaction Gateway to participate in global
transactions. This section describes how to configure a single CICS Transaction Gateway and multiple CICS Transaction Gateways in a
highly-available Gateway group.
Ensuring you have a working Gateway daemon configuration
Before
you configure CICS Transaction
Gateway with XA support you must have a working Gateway daemon configuration.
If you do not have a working Gateway daemon configuration, complete
the following tasks:
- Install CICS Transaction
Gateway.
- Configure RACF® authorization
for user ID and password authentication. For more information see Configuring for client certificate mapping.
Configuring the application server and client environment
with XA support
Deploy the CICS resource
adapters as described in
Deploying the CICS resource adapter.
- If your applications connect to CICS Transaction
Gateway in remote mode, you can use the ECI resource adapter from
any supported version of CICS Transaction
Gateway.
- If you have any applications which connect to CICS Transaction Gateway in local mode, you
must use the ECI resource adapter from the same release as your installed
version of CICS Transaction
Gateway.
Configuring the Gateway daemon with XA support
- Ensure that CTGRRMS services are enabled as described in Enabling CTGRRMS services.
- You must permit access for the Gateway daemon USERID
to one of the following RACF facilities
when XA support is enabled:
- ALTER access to the MVSADMIN.RRS.COMMANDS.** facility.
- ALTER access to the MVSADMIN.RRS.COMMANDS.gname.sysname
facility.
- gname
- is the logging group name and corresponds to the logging group
in the RRS administrative panels in ISPF. Set gname to the
value for the sysplex where the Gateway is running.
- sysname
- is the system name. Set sysname to the value for the LPAR
where the Gateway is running
If you give ALTER access to MVSADMIN.RRS.COMMANDS.** the Gateway
daemon is permitted to perform recovery operations for transactions
associated with any system name or logging group. This option requires
less administration but does not provide granularity of control.
If
you give ALTER access to MVSADMIN.RRS.COMMANDS.gname.sysname the Gateway
daemon is permitted to perform recovery operations for transactions
associated with the specified system name or logging group. This option
allows for greater granularity of control but requires a greater amount
of administration.
If workload is shared between multiple Gateway
daemons within a highly-available Gateway group, the Gateway USERID
must have ALTER access to each gname.sysname pair used by the
highly-available Gateway group.
- Set the xasupport configuration keyword in
the GATEWAY section of the configuration file (ctg.ini). For more
information see GATEWAY section of the configuration file.
- Decide on a fully-qualified APPLID for the CICS Transaction Gateway instance.
If you
use TCP/IP load balancing across multiple Gateway daemons in a highly-available
Gateway group, you must specify the same APPLID qualifier for each
Gateway daemon in the group; this denotes each individual Gateway
daemon's membership of the group. Gateway daemons
in a highly-available Gateway group can span multiple LPARs in a sysplex.
See Configuring identification using APPLID for more information about setting
a fully-qualified APPLID.
The APPLID and APPLIDQUALIFIER are
defined in the configuration file or as command line overrides.
The
Gateway daemon uses the following name format to register with RRS: CICSTG.APPLIDQUALIFIER.APPLID.
- Start each Gateway daemon as described in Starting CICS Transaction Gateway.
See Sysplex restrictions for information about z/OS® image restrictions.