IXGRPT1 analyzes
system logger-related I/O by calculating:
- Number of bytes written by users via IXGWRITE during the interval (SMF88LWB)
- Number of bytes written to interim storage during the interval (SMF88SWB)
- Number of bytes written to DASD during the interval (SMF88LDB)
- Number of bytes deleted from interim storage during interval without having
been written to the log data set (SMF88SIB)
- Number of deletes from interim storage during interval without having
been written to the log data set (SMF88SII)
- Number of bytes written to the DASD log data set and then deleted from
interim storage during the interval (SMF88SAB)
- Number of deletes from interim storage during interval written to the
DASD log data set and then deleted (SMF88SAI)
- Number of times the log stream was offloaded during interval (SMF88EO)
- Number of times a request was made by system logger to write log stream
data to DASD during the expiring SMF interval (SMF88LIO)
- Number of times system logger had to suspend before writing log stream
data to DASD because a previously-initiated write to DASD had not yet completed
during the expiring SMF interval (SMF99LIS).
When the percentage of resource in use by a log stream exceeds the high
offload threshold, data is asynchronously offloaded from interim storage to
DASD log data sets, and then deleted from interim storage. Thus, SMF88SWB
shows I/O from the main processor to interim storage. SMF88SIB shows the
success of an application in avoiding offloads for data that it intends to
delete from interim storage. SMF88SAB shows bytes deleted from interim storage
and implies I/O from the interim storage to DASD log data sets.