Hi all,
recently we've did a performance-evaluation on Apache 2.0.
Our testing machine software:
- debian sid / unstable with apache 2.0.54 with mpm worker
- kernel 2.6.11
Our testing machines hardware:
- dual-cpu machine (2 x AMD Opteron 1.6 ghz, 2048 mb ram and pci-x
busspeed to note the most important bottlenecks) connected with an
Avalanche machine emulating client-HTTP-requests via 3 ethernet-cables@
1Gbit (in total, 3 Gbit/s traffic flow is possible in that way).
Our main-configuration
- MaxClients: 8192
- ThreadPerChild: varied
We've had to determine how many users per second can download a 2
MB-file (so only request per transaction) and we wanted to determine the
optimal number of threads per process supporting the highest number of
(successfull) transactions/sec. We started with 10 requests/sec and
after 25 seconds, we augmented this to 20 requests/sec and so on up to
200 requests/sec (bandwidth becomes a bottleneck). The access-network
speed of the users is in theory unlimited (in practice, this boils down
to 110 Mbit/s). So we started with 2 threads per child and doubled the
number of threads with each new test up to 128 threads (which is the
maximum supported otherwise we get an error message - no memory left to
create a new thread). Now some "strange" results:
- 4 threads per process gives the best performance-results: up to 200
successfull transactions per second of the 2 MB file are realized.
(eventually, the CPU becomes the bottleneck)
- 8 threads per process gives worst performance: only 130 successfull
transactions per second are possible (and memory is clearly the
bottleneck here).
- 2 threads per process or 16 / 32 / 64 / 128 threads per process gives
almost similar results: +/- 140 successfull transactions/sec are
supported (memory is the bottleneck - page faults / swapping starts ->
strange with only one file!)
Can someone explain this why I get that different results, especially
why exactly 4 threads is optimal. If someone is interested in the
graphs, I can always mail them as a jpeg-figure.
Thanks in advance!
With kind regards,
Davy De Winter.
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: [EMAIL PROTECTED]
" from the digest: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]