Performance problems with IBM universe

[albcantabria]

We have serious problem of performance with an IBM universe Database over HP 9000.
We suspect IO problem.
Any idea or experience with this.
Regards.

[Steven E. Protter]

Shalom,

Perhaps measure performance:

http://www.hpux.ws/system.perf.sh

SEP

[Andy Torres]

Depends on versions, but at my previous job we saw some performance gains after several attempts, including adding CPU, switching arrays from HP XP to EMC DMX, database tweaking, application tweaking, etc. IBM also worked a special version patch for us at the time, too. So many things were done to that Superdome that it's tough to pinpoint the actual improvement. But the greatest gains came when we upgraded from HP-UX 11.0 to 11.11.

[albcantabria]

Uname -a
B.11.11 U9000/800
is still necesary the path? what is it?.

HP have internal disks. 120GB. All Volumes in raid 1 (mirror).

[albcantabria]

I attach the HP_perf_info report.

This is a piece of them:

HP-UX dmsreae1 B.11.11 U 9000/800 04/04/06

21:36:46 device %busy avque r+w/s blks/s avwait avserv

21:40:15 c0t6d0 100.00 8.05 224 9200 37.61 33.28
c3t6d0 81.82 5.53 223 9426 21.13 22.66
21:40:16 c0t6d0 100.00 25.94 253 7748 101.63 30.86
c3t6d0 82.00 9.32 241 7604 27.89 22.25
21:40:17 c0t6d0 100.00 21.45 296 7780 75.04 24.55
c3t6d0 92.00 19.24 289 7760 64.55 23.01
21:40:18 c0t6d0 100.00 25.27 305 7328 81.12 23.54
c3t6d0 91.00 22.92 293 7152 65.73 22.35
21:40:19 c0t6d0 100.00 28.71 316 6076 97.83 23.84
c3t6d0 91.00 24.42 308 6080 77.40 21.59

[albcantabria]

New system capture with system overload.

[Rodney Hills]

Universe databases can generate a lot of execessive I/O if the hash files are sized to small and universe has to access the overflow pages.

Look for the file(s) that are badly sized. You can use the FILE.STAT and HASH.HELP commands to determine the proper sizing.

If you have "glance" you can monitor the process looking for files with high I/O activity.

If you have "lsof", then you can use the perl script I am attaching to monitor a process looking for changes in disk activity for each open file.

HTH

-- Rod Hills

[albcantabria]

Thanks Rod.
Could you send me the script (or tell me an URL to download it).

[Rodney Hills]

Here is the script...

Rod Hills

[Bill Hassell]

Universe uses hundreds to thousands of files but because it was originally written when a single program could only open a few dozen files at one time, a file pool is configured for each program. If the pool is small (less than 100) then each program will be constantly opening and closing files (seen very drmatically by sar -a 1 10. These stats are directory activity stats and Universe can kill performance when it has to constantly ope/close files. If you increase MFILE (I believe that is the variable name in the Universe config file) to about 500 or even 900, you should see a major improvement in performance.

NOTE: nfile is the kernel parameter limiting the number of open files for the entire system. If you add 400 to MFILE, you will have 400 additional files open at the same time for each Universe program. Make sure nfile is large enough to handle the largest number of Universe programs.