Naming journals

The journals have the following naming conventions.

System logs

DFHLOG and DFHSHUNT are the journal names for the CICS® system log. CICS automatically creates journal table entries for DFHLOG and DFHSHUNT during initialization as shown in Table 8.

Table 8. Journal name entry for the CICS primary system log
Journal table entry - CICS system log Created during system initialization
Name: DFHLOG Always DFHLOG for the primary log
Status: Enabled Set when journal entry created
Type: MVS™ The default, but it can be defined as DUMMY on JOURNALMODEL definition (DUMMY = no output)
LSN: log_stream_name By default, log_stream_name resolves to &reguserid..&applid..DFHLOG, but this can be user-defined on a JOURNALMODEL definition

Forward recovery logs

For non-RLS data sets that have not specified their recovery attributes in the VSAM catalog, forward recovery log names are of the form DFHJnn where nn is a number in the range 1-99. You define the name of the forward recovery log in the forward recovery log id (FWDRECOVLOG) in the FILE resource definition.

User applications can use a forward recovery log through a user journal name that maps on to the same log stream name. In this case, the user records are merged on to the forward recovery log. See Table 9 for an example of this.

Table 9. Example of journal name entry for non-RLS mode forward recovery log
Journal table entry - forward recovery log Entry created during file-open processing
Name: DFHJ01 Name derived from FWDRECOVLOG identifier. For example, FWDRECOVLOG(01) = DFHJ01, thus FWDRECOVLOG(nn) = DFHJnn
Status: Enabled Set when journal entry created
Type: MVS The default, but it can be defined as DUMMY on JOURNALMODEL definition (DUMMY = no output)
LSN: log_stream_name By default, log_stream_name resolves to &reguserid..&applid..DFHJ01, but this can be user-defined on a JOURNALMODEL definition
Note:
There is no journal table entry for the forward recovery log of an RLS file. The recovery attributes and LSN are obtained directly from the VSAM catalog, and the LSN is referenced directly by CICS file control. Therefore there is no need for indirect mapping through a journal name.

You can also choose to specify the recovery attributes and LSN for a non-RLS file in the VSAM catalog.

User journals

CICS user journals are identified by their journal names (or number, in the case of DFHJnn names), which map on to MVS log streams.

You name your user journals using any 1-8 characters that conform to the rules of a data set qualifier name. Apart from the user journal names that begin with the letters DFHJ, followed by two numeric characters, you should avoid using names that begin with DFH. User journal names of the form DFHJnn are supported for compatibility with earlier CICS releases.

Although 8-character journal names offer considerable flexibility compared with the DFHJnn name format of previous releases, you are recommended not to create large numbers of journals (for example, by using the terminal name or userid as part of a program-generated name).

Journal name DFHLOG (on an EXEC CICS WRITE JOURNALNAME command) indicates that you want to write to the CICS system log.

When used in FILE and PROFILE resource definitions, the journal numbers 1 through 99 map on to the user journal names DFHJ01-99. You can map these journal names to specific MVS log stream names by specifying JOURNALMODEL resource definitions, or allow them to default. If you do not specify matching JOURNALMODEL definitions, by default user journals are mapped to LSNs of the form userid.applid.DFHJnn.

Table 10 shows an example of a user journal name table entry.

Table 10. Example of a user journal name entry for output to MVS
Journal table entry - user journals Entry created on first reference
Name: JRNL001 Name derived from API WRITE JOURNALNAME command
Status: Enabled Set when journal entry created
Type: MVS This journal is defined for MVS output by a JOURNALMODEL that references the JRNL001 name
LSN: log_stream_name By default, log_stream_name resolves to &reguserid..&applid..JRNL001, but this can be user-defined on a JOURNALMODEL definition

Installing system log and journal names

The journal control table of earlier releases is obsolete, and is replaced by a journal names table that CICS creates dynamically.

The CICS log manager needs the name of the log stream that corresponds to a CICS system log or general log, and the type - whether it is MVS, SMF, or a dummy. Except for VSAM forward recovery log stream names taken directly from the ICF catalog, CICS maintains this information in the journal names table, together with the corresponding log stream token that is returned by the MVS system logger when CICS successfully connects to the log stream.

[[ Contents Previous Page | Next Page Index ]]