Re: Saving the System i: Fight Rather Than Switch

[Nathan Andelin <nandelin@xxxxxxxxx>]

> Walden Leverich wrote:
> Are you saying WebSphere won't take advantage
> of multiple processors?

My comment about needing 32 instances of Websphere to utilize a 16-way server 
was based on a  case study I downloaded from an IBM Web site a few years ago, 
featuring an application that was deployed across 64 instances of Websphere, 
running on a 32-way server.

In the beginning, they tried deploying the application under a few instances of 
Websphere - setting the thread count as high as possible.  Throughput was 
horrible while most of the CPU's remained idle under that approach.  Reducing 
the thread count and running more instances of the application server was their 
final attempt at making it scale.

Of course, you can't use any one particular case study as a benchmark for every 
workload, but my impression was that Websphere application server itself was 
the bottleneck, which is counter intuitive.  Threaded applications should 
theoretically spread their workloads across all processors.

I read something similar about ASP .Net architecture, where companies were 
deploying applications under out of process servers, with each server hosting a 
separate instance of the Common Language Runtime, which in my mind is 
comparable to running multiple instances of a Java Virtual Machine.

Nathan.







 
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