RRS use of XCF

RRS uses a single XCF group, called ATRRRS, to communicate between images in a sysplex. No special processing is required by an installation to enable RRS usage of XCF. You do not need to modify XCF transport classes. See z/OS MVS Setting Up a Sysplex for more information.

Should the need arise where a z/OS® V1R10 system needs to fall back to a lower release, a fallback toleration APAR, number OA23153, should be installed to allow the lower level of RRS to start and preserve the Archive Logging preference from the SETRRS command. Without this APAR on the lower level system, RRS will not be able to start on that system. This will be identified with the messages:

ATR235I RRS FAILED TO JOIN THE RRS XCF GROUP. RC = 00000008, RSN = 00000010
ASA2013I RRS INITIALIZATION FAILED. COMPONENT ID=SCRRS

In this case, RRS must be removed from the XCF group on the lower level system to allow the RRS restart. This can be done by the following steps:

Steps to Remove RRS from XCF:

Note: When completed, the Archive Logging Enable/Disable setting on the V1R10 system will be deleted.

Set up the proper access authorization to the Facility Class Resource MVSADMIN.XCF.IXCM2DEL. If your installation uses the RACF® component of SecureWay for z/OS, this can be done from an authorized userid using the following commands:
- RDEFINE FACILITY (MVSADMIN.XCF.IXCM2DEL) UACC(ALTER)
- SETROPTS RACLIST (FACILITY) REFRESH
Code up, submit, and review the output from the following JCL sample. The source for the JCL can be found in SYS1.SAMPLIB member IXCDELUT and more details can be found in the Deletion Utility for XCF Group Members section in z/OS MVS Setting Up a Sysplex.
```
//IXCDELUT JOB
//S1  EXEC  PGM=IXCM2DEL,PARM='ATRRRS,mem01'
//SYSPRINT  DD   SYSOUT=A 
```
Where:
```
mem01 is the member name of the member to be deleted.
```
mem01 can be determined by issuing system command:
```
D  XCF,GROUP,ATRRRS
```
which results in message:
```
	IXC332I  09.49.44  DISPLAY XCF     
	GROUP ATRRRS:      SY1                SY2
```
Using the above display as an example, mem01 should be replaced with either SY1 or SY2 depending on which system RRS is being removed from.
Upon successful completion of the JCL job, RRS will now be able to start on the lower level system.