Thursday, April 30, 2009

Day 30 - Performace Tests

There's a set of performance tests to do before choosing the final migration infrastructure.
There's tests over the initial data extraction from OS/390 and loading into AS/400.
There's tests over the data transformation rules.
There's tests over the final data loading into GIS.

From this set of tests, only ours, the data transformation rules, have been performed so far.
As expected, AS/400 is not a fast machine to run Data Fusion transformation engine. We already knew this, but AS/400 system administrators always say we're wrong and that they have a fantastic and fast machine. Their pride has been hurt...

As an example, running entirely in AS/400, 400000 source records have migrated at ~800 records per secord. Note that this was a local data migration execution, the source and target databases are on the same machine as the transformation engine.
But running the same transformation engine on my, not very fast, desktop computer with 1GB of RAM, the same 400000 records migrated at ~1400 records per second. Note that on this test the source data was retrieved from AS/400, transformed on my desktop compute, and sent back to AS/400, i.e. the data had to travel over a common 100 Mbit network.

The protocol loading interface was also subject to tests and it's CPU bounded, We have one single processor, of a 4 processor machine, and it consumes 100% of that CPU. When running on AS/400, it perfomed ~12000 records per second. Running on the desktop it does only ~8000 records per second.

The scalability tests on AS/400, with a single CPU for us, proved that a linear execution is faster than a two parallel executions. We haven't had the chance to test parallel execution with more CPUs.

We've been discussing what was the best approach allow us to scale and one thing is for sure, we need to run the transformation engine outside the AS/400, because on the D day we have to share, as it's happening now, the machine with others, specifically with GIS data loading.
Probably we'll have a 6 or 8 CPU machine running Linux and connected to AS/400 over a 1 Gbit network. This will allow us to run multiple transformation engines and free AS/400 for the other data migration processes.

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