80 IMS in the Parallel Sysplex, Volume III: IMSplex Implementation and Operations
3.14 DBRC address spaces
All of the address spaces which invoke DBRC are eligible to participate in automatic RECON
loss notification function. To do this, they must join the IMSplex either by coding
IMSPLEX=plexname in their execution JCL, or by using exit DSPSCIX0. The exit is easier,
otherwise you have to change all the following jobs or procedures:
Online DBRC
DBRC batch utilities (DSPURX00)
Batch jobs with DBRC=Y
Database utilities with DBRC=Y
The RECON header record includes an IMSPLEX name, so if a DBRC job tries to join the
plex using a set of RECONs for another IMSplex, it will not be able to access the RECONs.
3.15 IMSplex security
The way you establish resource security for the IMS online system does not change for an
IMS in an IMSplex. The resources that can be protected and the facilities available to protect
them are similar.
3.15.1 Security issues
The two types of security issues for a single IMS also exist for an IMS within an IMSplex. You
must address one or both types of security issues:
Securing the kind of resource to which a user has access
Securing what the user can do to the resource after the user has access to it
If commands are entered through OM API, we recommend that you perform all security
checking in OM. To authorize classic commands from OM, you must set the appropriate value
for the CMDSEC= parameter in DFSCGxxx.
If SCI registration security is desired, include IMS control region in RACF definitions.
3.16 Miscellaneous considerations when implementing CSL
There are few additional things you may want to be aware of when implementing the CSL:
All new address spaces default to ARM=Y. This is usually good.
There are many new and changed messages and abends (and some deleted ones too)
See Chapter 6 of
IMS Version 8: Release Planning Guide,
Log record format changes
See Chapter 29 of
IMS Version 8: Release Planning Guide,
Chapter 3. Implementing the Common Service Layer (CSL) 81
3.16.1 RSR
If using RSR, the tracking site does not have to have CSL; however, if it is active, then the
tracking site can take advantage of OM for command entry and SCI for automatic RECON
loss notification (ARLN).
RSR tracking system can connect to a CSL to enable automatic RECON loss notification and
to receive OM commands. If CSL available is available on the tracking site, tracking IMS
registers with SCI and registers commands with OM. CSL is not required for tracking function,
but it should be available if takeover is required. If using shared queues, takeover site must
cold start, which means no message or status recovery is available at takeover.
3.16.2 Features not affected by CSL or STM
Many features are not affected by the implementation of CSL and STM (described in detail in
the next chapter). Some are listed here:
Application programs
Except CMD and ICMD entered commands may have local or global scope (same as
terminal entered commands)
MSC, SPOOL API, FES, associated printers, time-controlled operations (TCO)
APPC (except for APPC descriptor name consistency)
Definitional consistency of attributes across IMSs in IMSplex not verified for:
IMS system defined resources
APPC descriptors, ETO descriptors
82 IMS in the Parallel Sysplex, Volume III: IMSplex Implementation and Operations

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