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Performance problems with HP-UX 11.31 and Sybase

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Martha Mueller
Super Advisor

Performance problems with HP-UX 11.31 and Sybase

We have replaced an old rp5470 running hp-ux 11.23 and sybase 12.5 with a new rx2660 running hp-ux 11.31 and sybase 15.

We are crippled. A test procedure can complete in 5 minutes on the old system, but takes 12 minutes on the new system. The storage system for both is the same EMC Clariion CX3-40C.

I have read the thread:
http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1209129

I welcome any additional advice while we pursue the other thread's information.
15 REPLIES

Re: Performance problems with HP-UX 11.31 and Sybase

Martha,

Thanks for opening another thread... sorry for being a stickler there, but I think it helps.

So from what you posted before I'm assuming you *are* using PowerPath 5.1 on this 11.31 host?

My first reaction would be - why? I'm not sure PP adds anything on 11.31 that isn't provided by the OS, unless EMC can explain some value to me...

So secondly if you are using PP5.1, can you confirm that you are using the legacy DSFs (/dev/dsk and /dev/rdsk rather than /dev/disk and /dev/rdisk).

And can you confirm that native multipathing for legacy DSFs is disabled?

HTH

Duncan

HTH

Duncan
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

Yes, we are using PowerPath 5.1. We use it for the failover feature. In our past, we had a very early Clariion, an fc4700, and used pvlinks for failover. We had so much trouble, pvlinks could not fail over fast enough to keep sybase happy, we had data corruption.

When I run ioscan, it shows the legacy DSF's

I don't know what you mean about native mulitpathing for legacy DSF's is disabled? We don't have any alternate links showing up when I run vgdisplay.
Solution

Re: Performance problems with HP-UX 11.31 and Sybase

You wouldn't be using PVlinks with 11.31 - you'd be using the native MPIO...

I'm assuming the devices listed in your VG configuration are also legacy DSFs?

Anyway to check that legacy DSF MPIO is disabled, first identify the agile DSFs for your legacy DSFs using:

ioscan -m dsf

Then check the atttribute for each disk as follows:

scsimgr get_attr -D /dev/rdisk/diskX -a leg_mpath_enable

You should expect all the clariion devices to be set to false

HTH

Duncan

HTH

Duncan
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

they are all set to false, and vgdisplay does show the legacy names.

Re: Performance problems with HP-UX 11.31 and Sybase

then I guess it's time to start looking elsewhere for the performance issue.

A good starter would be to compare the job on the old box vs on the new one... how do you kick the job off? From the command line? Are you in a position to compare resource utilisation on both systems for the same job?

HTH

Duncan

HTH

Duncan
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

o Server 1: Sybase ASE 12.5.3 ESD#5 on HPUX 11.23 PA-RISC
o Server 2: Sybase ASE 15.0.2 ESD#6 on HPIA 11.31 Itanium
o Each server was configured with 2 engines.
o The test consisted of executing 200 iterations of a stored procedure that is used frequently in our application. We ran 3 simultaneous sessions.
o The test completed in 7 minutes on the 12.5.3 server.
o It completed in 13 minutes on the 15.0.2 server.
Patrick Wallek
Honored Contributor

Re: Performance problems with HP-UX 11.31 and Sybase

How do the server configurations compare? How many CPUs and how much RAM in the old and new servers?

How does CPU utilization and RAM utilization compare on the 2 servers?

Are the Sybase DB's indexed similarly? Could the procedure be doing a full table scan on one server and using an index on the other?

Is there a Sybase equivalent to Oracle's SGA? Is that set up similarly? Any other Sybase DB setups that could be different?

Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

My boss just came back with an update....the dba's were able to recreate the poor performance on the old server. There apparently is some kind of an option that was set on the stored procedure ... it was running "with recompile" on. By turning off this option, they were able to get good performance on the new server, and vice versa.

They are still investigating, but this procedure is called something like 4000 times an hour, and small improvements will make a lot of difference.

But, to answer your question in a general sense, the new server should have been much more powerful than the old. The old rp5470 has 10 GB of memory and three 750 MHz processors. The new rx2660 has 16 GB of memory and two 1.6 GHz processors.

The DBA's have been working with Sybase to resolve this issue, but there have been no table scans. We did run into that problem many years ago, and the symptoms are the same, just as you suggest.

Re: Performance problems with HP-UX 11.31 and Sybase

memory and CPU on both systems?

were the tests completed with nothing else running... did you compare CPU usage and IO using sar -Mu and sar -d

HTH

Duncan

HTH

Duncan
TTr
Honored Contributor

Re: Performance problems with HP-UX 11.31 and Sybase

> ...with a new rx2660 running hp-ux 11.31 and sybase 15...

Is your ASE 15.0.2 version built for the itanium platform?
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

the new server should have been much more powerful than the old.

The old rp5470 has 10 GB of memory and three 750 MHz processors. The new rx2660 has 16 GB of memory and two 1.6 GHz processors.

We can see that cpu usage was going way up, we used Performance Manager measureware agents, and the dba's use their sybase tools.
We ran at 98 to 100% cpu usage.

And, yes, the version of sybase was for itanium. That is a good point. We had to get this version when this new server arrived.
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

Performance is much better today, after the sybase change.

Re: Performance problems with HP-UX 11.31 and Sybase

Hi,

I'm having some sybase performance problem also since the migration from PA-RISC to Itanium. You noticed that your performance are better since the Sybase change. What change did Sybase to your configuration ?

Thank you!
Kind regards
Philippe RITTER
Martha Mueller
Super Advisor

Re: Performance problems with HP-UX 11.31 and Sybase

I don't think the DBA's made any change to the Sybase configuration as a whole, but made a change to a single stored procedure that is called frequently. That change had something to do with an option "with recompile". Seems that in Sybase 15, as opposed to Sybase 12.5, there are new options to try to optimize code. In routines that will run quickly, this "with recompile" option hinders, rather than helps performance. If it were a long running procedure, then it would probably help performance.
Bill Hassell
Honored Contributor

Re: Performance problems with HP-UX 11.31 and Sybase

> Sybase 12.5.3 versus 15...

That is a big jump from very old Sybase code. Your DBA must start all over from the beginning when configuring Sybase 15. The extra memory is useless until you tell Sybase to use it. There are many new options in 15 but if they are not selected or set to take advantage of the extra memory. Since most Sybase setups use raw disks, be sure to setup 11.31 multi-pathing to take advantage of your EMC controller speed. Be sure to checkout compatibility patches for 11.31 to allow PowerPath to work correctly.


Bill Hassell, sysadmin