13.1.7 Expanding the user log buffers
This subsection explains how to improve processing performance by re-evaluating the value of the adb_log_usrbuf_num operand in the server definition.
If the user log buffers become full, user logs are purged from the user log buffers and output to user log files. Because I/O operations on the user log files occur when the user log buffers are purged, update processing performance might deteriorate. Therefore, check whether the allocated number of user log buffers is appropriate.
Procedure
-
Check the number of times the user log buffers were purged because they became full.
Check the following item in the information that was output when the adbstat command was executed:
-
Log_usrbuf_out_cnt (number of times the user log buffers were purged because they became full)
- Note
-
For details about the adbstat command, see adbstat (Perform Statistical Analysis of the HADB Server) in the manual HADB Command Reference.
-
-
Revise the value specified for the adb_log_usrbuf_num operand.
If the value that is output to Log_usrbuf_out_cnt, which you checked in step 1, is at least 1, purging of the user log buffers has occurred. In such a case, expand the number of user log buffers by increasing the value of the adb_log_usrbuf_num operand in the server definition. Expanding the number of user log buffers will prevent purging of the user log buffers caused by full buffers during update processing.
- Important
-
Expanding the number of user log buffers will increase the amount of process common memory required when the HADB server starts. Re-estimate the amount of process common memory required when the HADB server starts by following the explanation in (g) Determining the variable RECCTL under (3) Determining the process common memory requirement (for starting the HADB server) in 6.3.3 Determining the memory requirement for starting the HADB server.
-
Terminate the HADB server.
Terminate the HADB server by executing the adbstop command.
-
Change the server definition.
Increase the value specified for the adb_log_usrbuf_num operand in the server definition.
-
Start the HADB server.
Execute the adbstart command to start the HADB server.
- Note
-
For details about the adb_log_usrbuf_num operand in the server definition, see the adb_log_usrbuf_num operand in 7.2.3 Operands related to system logs (set format).