Problem of running Sybase(3)

[mxshao]

Hi,
The system is Sybase 11 running on HP-UX 11.0, but the speed is slow sometimes. The situation happens when the clients access DB server. But it is not always so.
I wonder how to resolve this problem. If someone need configuration files, I will provide them.
Any message will be helpful.
Thanks

[Alex_7]

Hello,

see your Sybase documentation and tune the kernel or check if the Sybase is compatible with OS(HP-UX is 32/64 bits OS). After you check this, use glance, top and sar to verify utilization of resorces.

[UCI]

Hi,

I had also this problem with Sybase and HP-UX 11.00.
The problem is sql statements. When somebody starts a sql then you see that the idle% go down (use sar). The larger the sql the longer the system is slow.
There are two ways to solve this problem:
1. Tuning kernel
2. Use more embedded sql (I think that's called procedures in Sybase).

[Xavier Izquierdo]

I have encountered this problem before with Sybase on UX10.2 and 11. As mentioned before it is very important to first tune your Kernel on HPUX, make sure your devices are running with AsyncIO on, if applicable, then tune your Sybase config files to match your system utilization and Kernel setting. Sometimes in the mix of everything a Sysadmin has to do the Kernel is tuned perfectly but the Sybase config files do not match the settings or the other way around. If you have specific problems let me know and I will try to help.

[Xavier Izquierdo]

I have encountered this problem before with Sybase on UX10.2 and 11. As mentioned before it is very important to first tune your Kernel on HPUX, make sure your devices are running with AsyncIO on, if applicable, then tune your Sybase config files to match your system utilization and Kernel setting. Sometimes in the mix of everything a Sysadmin has to do the Kernel is tuned perfectly but the Sybase config files do not match the settings or the other way around. If you have specific problems let me know and I will try to help.

[Philip Chan_1]

Check out the followings,

1. asyncdsk driver must be included in your hpux kernel.

2. shmmax hpux kernel parameter should be equil to or bigger than your physical memory size.

3. check your sybase memory -> sp_configure "total memory", don't leave it at default which is too small for good cache peformance.

4. check out the runnable process search count -> sp_configure 'runnable process search count', if it is not at default then change it back to default.

5. while your machine is slow, run "sar -Mud 2 9" to see if you ran into CPU or disk bound situation. If disk bounded, go back to your sql program to make sure they don't cause table scan problems. If CPU bounded then you got whole lot more work to do. Also run "top" to make sure there are no other program that occupied the CPU.

6. make sure no livelocks in Sybase, while your machine is slow check output from "sp_who", look at the "block by" column.

Give it a try and good luck !!!