PAGEABLE_CACHE setting in the DSConfig.txt

[Former Member]

When we change the PAGEABLE_CACHE_BUFFER_POOL_SIZE_IN_MB setting in the DSconfig.txt from 4092 to 8184 all the job fails. However when it is reset back to 4092 the jobs work fine.

The product version is 12.0 and Server specs are

Windows 2003 R2 (32-bit),

8xCPU (@Intel Xeon 2.93GHz)

16 GB RAM

Please advice what this is happening. Also mention PAGEABLE_CACHE_BUFFER_POOL_SIZE_IN_MB setting is dependent on which parameters. Is there a minimum and maximum size.

Thanks and Regards

Ajita.

[werner_daehn · Accepted solution]

It's an upper limit for the memory consumption. Every requirement above will get swapped to disk.

This parameter controls at what amount of memory the pageable_cache driver starts to overflow to cached data to disk.

If it is set to 100MB it will - if needed - cache the data up to 100MB and everything above that will be swapped to disk one a least-recently-used kind of algorithm.

If it is set to 1000MB, same thing. The pageable cache uses up to 1000MB of memory, everything beyond that is swapped to disk.

If you set it > 2GB it will allocate more than 2GB of memory - if so much memory is even needed to cache your data - and terminate with an error as a 32bit process cannot be bigger than 2GB. By default on a Windows environment it is set to 1.5GB.

[Former Member · Accepted solution]

Hi Werner,

As far as I know, 32th of 2 is 4G, 2G used for kernel, the rest 2G is used for application. I wonder, is that 4096 means 2G or 4096M (4G)? What will happen if /3GB is turned on? Will DS allocate 3G in memory?

Cheers,

Henry

[werner_daehn · Accepted solution]

I don't know what 4GB means either, my hope it will get ignored. Anyway, I can confirm however that 1.5GB means 1.5GB of memory.

If you use the /3GB flag of AWE nothing will change as our application is not compiled that way to benefit from that. And quite frankly, if you need to cache so much data I wonder if you wouldn't be performing better when changing the design of your flow a bit.

[Former Member · Accepted solution]

thank you Werner. I already forgot 4GB

My last concern to this issue is, if I need to change it into 1.5G, do I just use 1.5G or 1536 for para PAGEABLE_CACHE_BUFFER_POOL_SIZE_IN_MB? I would think 1536 is the answer.

Cheers,

Henry

[werner_daehn · Accepted solution]

Correct.

[Former Member · Accepted solution]

Thanks...

[Former Member]

Therefore, does this mean that BODI have memory limitation of 2GB for In-Memory processing, while 4GB for Pageable Cache?