[Info-vax] Apache + mod_php performance

[Dan Cross]

In article <vd7hbi$tgu3$2 at dont-email.me>,
Arne Vajhøj  <arne at vajhoej.dk> wrote:
>On 9/25/2024 5:10 PM, Arne Vajhøj wrote:
>> It must be Apache.
>> 
>> Apache on VMS is prefork MPM. Yuck.
>> 
>> MaxSpareServers 10 -> 50
>> MaxClients 150 -> 300
>> 
>> actually did improve performance - double from 11 to 22
>> req/sec.
>> 
>> But the system did not like further increases. And besides
>> these numbers are absurd high to handle a simulator doing requests
>> from just 20 threads.
>> 
>> But not sure what else I can change.
>
>And we have a solution.
>
>httpd.conf
>
>KeepAlive On
>->
>KeepAlive Off
>
>And numbers improve dramatically.

Hmm. You had already said that you were _Not_ using keep alives
because that would somehow mimic multiple machines querying
simultaneously.

This was, of course, the area of investigation I had suggested
to you previously to try and nail down the baseline.  I question
whether this will impact your single query latency, however, or
whether this is masking it in your benchmark.

>nop.txt 281 req/sec
>nop.php 176 req/sec
>real PHP no db con pool 94 req/sec
>real PHP db con pool 103 req/sec
>
>Numbers are not great, but within acceptable.

What is your single query latency?  Not calculated, but
actually measured.

>It is a bug in the code.

The evidence in hand is insufficient to make that claim.

>Comment in httpd.conf say:
>
># KeepAlive: Whether or not to allow persistent connections (more than
># one request per connection). Set to "Off" to deactivate.
>
>It does not say that it will reduce throughput to 1/10'th if on.
>
>And note that keep alive was not needed for me, but it is needed in many
>other scenarios:
>- web pages with lots of graphics
>- high volume server to server web services

Actually, it's useful for any scenario in which you may send
several requests to the same server at roughly the same time,
such as an HTML document and separate CSS stylesheet, not just
graphics or "server to server web services".

	- Dan C.