Processing EVENTLOG records

The previous section discussed the various methods for allocating the EVENTLOG data set to obtain the desired records. This section will discuss how to interpret the data returned by the SDSB interface.

If the EVENTLOG data set has been allocated in a manner where all data set records will be returned, each record will consist of a record prefix followed by the record data. The record prefix is defined by the EVENTLOG record prefix (IAZLGINF) mapping macro. The prefix contains the information needed to determine the type of record returned by the SDSB interface. The record type is contained in field LGPRTYPT, and indicates what mapping macro should be used to interpret the record data. For example, if the returned record type is LGPRSMF, then the record data will contain an SMF record type and SMF macros would be used to interpret the record data. If the record type is LGPRSTEP, then the record data contains STEPDATA and the STEPDATA mapping macro IAZLGSTP is used to interpret the record data. A record type of LGPRRST, indicates a RESTART record and RESTART mapping macro, IAZLGRST, is used to interpret the record data. For more information on these macros refer to Record prefix (IAZLGINF) mapping macro, STEPDATA (IAZLGSTP) mapping macro, and RESTART (IAZLGRST) mapping macro. For more information on SMF records and how to interpret their data see z/OS MVS System Management Facilities (SMF).

In these situations, the type of data being returned is known by the requestor so no record prefix is returned. Only record data is returned and the requestor uses the proper mapping macro to interpret that record type.