On Tue, Feb 11, 2003 at 03:11:36PM -0800, David Burry wrote: > Because the client will contend very heavily with the server for many > system resources. It's indeterminate which one (client or server) > requires more resources, which one wins more, and how much more of which > resources.
Well, I am not defending this server/client-on-one-system is better or anything. Just want to understand this better. Isn't the clients block when the servers can not response? From a higher level of point of view, the system is a closed queuing system. In the steady state there should be a balance between servers and clients, right? > Running both on the same machine will certainly stress the > machine pretty well, but you can't compare any measurement you get with > what the same machine will perform if Apache doesn't have to contend > with a client for its resources, it won't be the same result at all. We have no intention to compare these two at all. Our goal was to achieve a reasonable workload that runs similarly as the real world application. > In > the real world apache doesn't have a client stealing its system > resources, therefore an accurate test of how apache would behave in the > real world can only be done if you set up a test with the same > situation. This could be why apache is performing better when you let > your client sleep a little (then again, it could be something else, > that's why I say it's "indeterminate" (unknown) how much of the > resources the client itself is stealing away from the server). To > measure the effect of anything, you have to limit the number of > variables that can influence the result. I agree. We indeed tried other experiments to test this hypothesis. We first used separate machines for the clients and this behavior disappeared. But I think the reason was the network(ethernet) latency between those server and client machines enssentially served as the small delay time I have added in the singal machine case. On the other hand, I have used solaris "psrset" to logically divide the 14p server into "two" machines, and I bind the server and the client to different processor sets. And the results shows again the small delay time have important impact on system throughput. How strange! -- Rapid keystrokes and painless deletions often leave a writer satisfied with work that is merely competent. -- "Writing Well" Donald Hall and Sven Birkerts
