Increasing the size of the 128K memory pool

[former_member207908]

Dear Team

My requirement: To increase 128K memory pool

I want to know, inorder to increase this parameter, do we need to increase max memory and then increase 128K memory pool?

Or

Can we shift the 16K memory pool's size ti 128K memory pool?

Cache: default data cache,   Status: Active,   Type: Default

      Config Size: 8294.40 Mb,   Run Size: 8294.40 Mb

      Config Replacement: strict LRU,   Run Replacement: strict LRU

      Config Partition:            8,   Run Partition:            8

IO Size  Wash Size     Config Size  Run Size     APF Percent

-------- ------------- ------------ ------------ -----------

    16 Kb     663552 Kb   6634.50 Mb   6634.50 Mb     10

   128 Kb     165888 Kb   1658.88 Mb   1659.00 Mb     10

==========================================================================

Cache: log cache,   Status: Active,   Type: Log Only

      Config Size: 512.00 Mb,   Run Size: 512.00 Mb

      Config Replacement: strict LRU,   Run Replacement: strict LRU

      Config Partition:            1,   Run Partition:            1

IO Size  Wash Size     Config Size  Run Size     APF Percent

-------- ------------- ------------ ------------ -----------

    16 Kb       2448 Kb     12.00 Mb     12.00 Mb     10

    32 Kb      61440 Kb    500.00 Mb    500.00 Mb     10

Regards,

Rajesh

[former_member207908]

Dear Mark,

Thank you for your valuable suggestions.

SAP says..

97% Prefetch data Size is bigger than 128k pool size, So it can't use the Large I/Os  pool.

This cause the message in errorlog  "server  The 128K memory pool of named cache default data cache (cache id 0, cachelet id 3) is configured too small for current demands (state 1). Transaction progress may cease or response time may increase."

Now, I want to know what is the best or near perfect value to configure 128K memory pool?

Issue: Client copy on a PROD server is slow

Error received: The 128K memory pool of named cache default data cache (cache id 0, cachelet id 3) is configured too small for current demands (state 1). Transaction progress may cease or response time may increase.

Pls suggest

Regards,

Rajesh

[Mark_A_Parsons]

re: "best or near perfect value" ... "It Depends!"

If you've only got a single thread that needs to use the 128K pool then you'll likely be ok by adding, say, 1GB to the 128K pool.

If you've got 3 dozen threads looking to use the 128K pool then you may need to add 5-10GB.

With little/no details all I can suggest is that you increase the 128K pool (eg, add 1GB), test your 'client copy' process and if still slow (due to 128K pool being too small) then increase the 128K pool again, test again, etc.

Recall that *just* increasing the 128K pool will reduce the size of the 16K pool ... which could potentially (negatively) affect some other processes that are looking to use the 16K pool ... in which case you may need to add memory to the cache.

[former_member187136]

Hello Mark,

Merry Christmas 🙂

Yes I do agree your comments, I really likes the word "Best Perfect Value"

As there is no perfect measure that we can say that the application or the process or the thread is extensively using 16K or 128K increasing to the nearest perfect value will definitely has breathing space below the deficit 🙂

Regards

Kiran Kumar A

[former_member207908]

Dear Mark

Im providing the following information, so that I could help me in solving the issue (client copy slowness)

1> sp_helpthread

2> go

Name                                                                 Type                                                                             CurrentSize                                  TargetSize                               IdleTimeout                                  Description                                                                                                                                                                      InstanceName                                

-------------------------------------------------------------------- -------------------------------------------------------------------------------- -------------------------------------------- ---------------------------------------- -------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------

syb_blocking_pool                                                    Run To Completion                                                                          4                                           4                                         0                                  A pool dedicated to executing blocking calls                                                                                                                                     NULL                                        

syb_default_pool                                                     Engine (Multiplexed)                                                                       7                                           7                                       100                                  The default pool to run query sessions                                                                                                                                           NULL                                        

syb_system_pool                                                      Run To Completion                                                                          4                                           4                                         0                                  The I/O and system task pool                                                                                                                                                     NULL                                        

                                                                                                                                        NULL

biggest table size 13 GB

topas showing 60%

Good news is that pageIn rate is now very low

But, disk I/O on shows very high contention: hdisk131 and hdisk129 (probably devices of specific tables)busy 91-97%.

Total throughput is under 100Mbs/s for a 10Gbps ethernet or modern FC SAN this is not the highest limit afaik, and should be much bigger.

E30_sar.txt.zip

C30_sar.txt.zip