how to configure params for buffer pool for named data cache?

[Former Member]

when create a named data cache on ase 12.5, it will setup 2K I/O buffer pool by default with Configured size=0, wash size = 60M

1. if 2K can be changed to 8K for this buffer pool?

2. If add another 16k buffer pool, should Affected Pool be changed to the right pool?

3. How to decide then pagesize, configured size and wash size for a buffer pool? Are they part of total memory size allocated for this cache?

[former_member188958]

> 1. if 2K can be changed to 8K for this buffer pool?

You should be able to create an 8K i/o pool, then drop the 2k pool by setting its size to 0.

> 2. If add another 16k buffer pool, should Affected Pool be changed to the right pool?

If you don't specify the Affected Pool (when calling sp_poolconfig), the procedure uses the pool with the smallest i/o.  So if you had an 8k but not had dropped the 2k, the space for the new 16k pool would come from the 8k pool.

> 3. How to decide then pagesize, configured size and wash size for a buffer pool? Are they part of total memory size allocated for this cache?

The wash is included in the pool. I don't think it usually needs to be adjusted.

Which page size pools to have will depend on how the cache is used.  Tables with a clustered index that have a lot of range queries will benefit from larger page size pools, as will text/image/java.   Syslogs is said to do well on a 4k pool.

-bret

[Former Member]

ad 1.

Actually the size of a pool with 2k size on a 2k server (generally the smallest pool) can not be set to 0.

The minimum size of the pool is 256 pages.

On a 2k server when you add 8k pool, still the 2k pool has to be 512kB size (on a 4k server - 1MB, etc.)

In your case you can set the size of the 8k pool in the cache to 59,5MB, that is 60928kB.

You could try to set the 2k pool manually in CFG file, still you will receive error:

Invalid pool size of 0k (0 buffers) encountered for the 2k pool in cache my_cache. Buf

fer pools must have a minimum total size of 512k or 25 buffers, whichever is greater.

Adam