The remote resources that you may have to define if you are using CICS® function shipping are:
A remote file is a file that resides on another CICS system. CICS file control requests that are made against a remote file are shipped to the remote system by means of CICS function shipping.
Applications can be designed to access files without being aware of their location. To support this facility, the remote file must be defined (with the REMOTESYSTEM option) in the local system.
Alternatively, CICS application programs can name a remote system explicitly on file control requests, by means of the SYSID option. If this is done, there is no need for the remote file to be defined on the local CICS system.
A remote file is defined using RDO. The definitions shown below provide CICS with sufficient information to enable it to ship file control requests to a specified remote system.
Resource definition online
DEFINE
FILE(name)
GROUP(.....)
DESCRIPTION(......)
Remote Attributes
REMOTESYSTEM(name)
REMOTENAME(name)
RECORDSIZE(record-size)
KEYLENGTH(key-length)
Although MRO is supported for both user-maintained and CICS-maintained remote data tables, CICS does not allow you to define a local data table based on a remote source data set. However, there are ways around this restriction. (See File control.)
The name of the remote system to which file control requests for this file are to be shipped is specified in the REMOTESYSTEM option. If the name specified is that of the local system, the request is not shipped.
The name by which the file is known on the local CICS system is specified in the FILE option. This is the name that is used in file control requests by application programs in the local system.
The name by which the file is known on the remote CICS system is specified in the REMOTENAME option. This is the name that is used in file control requests that are shipped by CICS to the remote system.
If the name of the file is to be the same on both the local and the remote systems, the REMOTENAME option need not be specified.
The record length of a remote file can be specified in the RECORDSIZE option.
If your installation uses the C language, you should specify the record length for any file that has fixed-length records.
In all other cases, the record length either is a mandatory option on file control commands or can be deduced by the command-language translator.
In some circumstances, two or more CICS systems can share a common CICS system definition (CSD) file. (For information about sharing a CSD, see the CICS System Definition Guide.) If the local and remote systems share a CSD, you need define each VSAM file used in function shipping only once.
A file must be fully defined by means of DEFINE FILE, just like a local file definition. In addition, the REMOTESYSTEM option must specify the sysidnt of the file-owning region. When such a file is installed on the file-owning region, a full, local, file definition is built. On any other system, a remote file definition is built.
To enable the local CICS system to access remote DL/I databases, you must define the remote PSBs in a PDIR. The form of macro used for this purpose is:
DFHDLPSB TYPE=ENTRY
,PSB=psbname
,SYSIDNT=name
,MXSSASZ=value
[,RMTNAME=name]
This entry refers to a PSB that is known to IMS/ESA® DM on the system identified by the SYSIDNT option.
The SYSIDNT and MXSSASZ operands are mandatory, because the PDIR contains only remote entries.
A remote transient data destination is one that resides on another CICS system. CICS transient data requests that are made against a remote destination are shipped to the remote system by CICS function shipping.
CICS application programs can name a remote system explicitly on transient data requests, by using the SYSID option. If this is done, there is no need for the remote transient data destination to be defined on the local CICS system.
More generally, however, applications are designed to access transient data destinations without being aware of their location, and in this case the transient data queue must be defined as a remote destination.
A remote definition provides CICS with sufficient information to enable it to ship transient data requests to the specified remote system. Remote definitions are created as shown in Figure 55.
Definition using CEDA
DEFINE
TDQUEUE(name)
GROUP(groupname)
DESCRIPTION(text)
Remote Attributes
REMOTESYSTEM(sysidnt)
REMOTENAME(name)
REMOTELENGTH(length)
A remote temporary storage queue is one that resides on another CICS system. CICS temporary storage requests that are made against a remote queue are shipped to the remote system by CICS function shipping.
CICS application programs can name a remote system explicitly on temporary storage requests, by using the SYSID option. If this is done, there is no need for the remote temporary storage queue to be defined on the local CICS system.
More generally, however, applications are designed to access temporary storage queues without being aware of their location. Whether or not the SYSID option has been coded on the temporary storage request, you could use an XTSEREQ global user exit program to direct the request to a system on which the appropriate queue is defined. If you use this method, there is again no need for the remote temporary storage queue to be defined on the local system. For programming information about the XTSEREQ and XTSEREQC global user exits, see the CICS Customization Guide.
If the temporary storage request does not explicitly name the remote system, and you are not using an XTSEREQ exit, then the remote destination must be defined in the local temporary storage table.
A remote entry in the temporary storage table provides CICS with sufficient information to enable it to ship temporary storage requests to a specified remote system. It is defined by a DFHTST TYPE=REMOTE resource definition macro. The format of this macro is shown in Figure 56.
DFHTST TYPE=REMOTE
,SYSIDNT=name
,DATAID=character-string
[,RMTNAME=character-string]