R
RussellAdams
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ndisk misleading results I agree completely. We understand that benchmarking tools aren't perfect, however with a 50G file and no filesystem cache we get excellent performance using direct IO and CIO. I would expect Progress to accomplish the same. There aren't really any magic switches to flip between AIX7 and AIX8. I agree there aren't any large changes between POWER7 and POWER8, with AIX7. None of my other customers with competing database software have any issues. Does your new LPAR span NUMA zones? This can be a huge problem. I've worked with AIX since RS/6000 and I've never had to investigate NUMA. Where do you see this, and is it documented for the POWER platform? Check your Progress startup parameters and DB settings to make sure they are the same. I understood them to be identical. We also tried with -direct and additional APWs. Still slow. Compare the output of the following commands on both AIX boxes.. looking for differences I'll go one better. Not only did we manually tune, and then try defaults, but we had IBM do a system trace down to the point where the IO is dispatched by the physical HBA. We were sub-millisecond in latency in every layer and IBM's layer 3 kernel team found no problematic configuration in the IO stack. The conclusion is the application just isn't trying. use nmon and iostat to compare what is going on with memory,cpu and disk during your tests (on both systems) Absolutely. We did. Existing production performs over 3000 IOPS during the job run, new systems do under 1000 IOPS. CPU is modest on existing production, and little to none on the new. We initially thought it was waiting on IO, now I'm not sure it wasn't just sitting there idling inside Progress. use promon to compare what is happening at a database level (on both systems) I'd love to. I'll ask the DBA. check the queue_depth settings on all of your disks using lsattr -El hdiskname Queue depths are not used. In fact, I'd argue we had a QD of 1 the entire time on the new systems. Does Progress do any concurrent read IO at all? How big is your database and each AIX LPAR? DB is approximately 500GB, 4 cores and 100GB RAM in AIX. SAN is high end EMC with 10 LUNs with interdisk policy striping. Each DB on a dedicated filesystem for DB and logs. Similar configurations at other customers with different DB software excels at IO. Is this batch job a single Progress session or a collection of processes? I believe this job is a serial series of batch jobs, one at a time. I think it's a nightly close and reporting run that executes sequentially.
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