DISKCACHE & pre-load hash file

[azens]

Hi all,

I use DataStage 5.2r2 on E10K machine with Solaris 8. There are 2 hash files stored surrogate key:

1) 8 millions of records, 430M bytes in size with 36 bytes in average record size.
2) 5.5 millions of records, 280 bytes in size with 32 bytes in average record size.

Both of them are static hash files.

Because hundreds of jobs reference these 2 hash files and at least 30 jobs run concurrently, I try DISKCACHE to improve performance. However, when DISKCACHE is on ( DISKCACHE = 512) and both hash files are set to WRITE.CACHE, all jobs hang. And in the end, whole DataStage system hang and I gotta restart DataStage and make DISKCACHE off to solve the problem. After that, although DISKCACHE is off, the performance is getting wrose, and even wrose than we havent tried DISKCACHE.

I also find a similar case in Ascential Software Knowledge Base, articale no. 18275, it notes that multi-processor system got this problem and the solution is set DISKCACHE off. I wonder that if multi-processor system got this problem, is DISKCACHE working on most UNIX machines?

If you have any experience about using DISKCACHE, please share with me. It will be very useful to me and your help is greatly appreciated.

Regards,


Azens Chang
MetaEdge Corp.