ASYNCBRING performance

Executive summary: ASYNCBRING saved 20% of SAV time - about 6 minutes on our box.

A couple of earlier threads mentioned using ASYNCBRING on SAV commands. I don't remember seeing actual performance numbers but the concept sounded interesting. I ran a test using our normal nightly backup procedure.

Testing was carried out on a 720 with one processor active and 8GB main memory to a Ultrium 5 tape drive in a dedicated backup procedure that uses ENDSBS(*ALL) with a BCHTIMLMT to achieve dedicated status. The SAV part of the system did not change much over the time period although there was slight increase in number of objects saved.



14 Backup Averages
  Obj       Saved SAV  time
Base   
473418  
1954
Asyncbring 490053  
1578
Change 16635  
-376
Percent 3.51%  
-19.24%
The SAV time is in seconds. The base backups were taking 33 minutes. We saved just over six minutes per backup using ASYNCBRING while saving 16,000+ more objects.

Procedure to measure...
Using TAATOOL CVTQHST to save the QHST data from the backup job. Match the SAVDLO (CPC9410) message and the SAV (CPC370C) message to create the SAV interval.

with start as                                               
  (SELECT * FROM backuphist where msgid = 'CPC9410'),
     end as                                                 
 (SELECT * FROM backuphist where msgid = 'CPC370C')
SELECT start.yymmdd,
       start.TIME,
       end.TIME,
       TIME(Substr(end.TIME, 1, 2)
            || ':'
            || Substr(end.TIME, 3, 2)
            || ':'
            || Substr(end.TIME, 5, 2)) - TIME(Substr(start.TIME, 1, 2)
                                              || ':'
                                              || Substr(start.TIME, 3, 2)
                                              || ':'
                                              || Substr(start.TIME, 5, 2)),
       Substr(end.msgtxt, 1, 9)
FROM   start
       JOIN end
         ON start.jobnam = end.jobnam
            AND start.usrnam = end.usrnam
            AND start.jobnbr = end.jobnbr
ORDER  BY 1,2

This gave results like this:

Date as  Time    Time    Numeric Expression  SUBSTR   
YYMMDD                                                
131229   033433  040638          3,205       474624 ob
131231   034221  041300          3,039       461412 ob
140101   115042  122126          3,044       461782 ob

Which in turn were deciphered in excel to turn 3205 into 32 minutes and 5 seconds = 1925 seconds. Last column is number of objects saved.

Conclusion:
ASYNCBRING is worth considering adding to your SAV commands.