[Info-vax] Apache + mod_php performance

[Arne Vajhøj]

On 9/27/2024 8:07 PM, Arne Vajhøj 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.
> 
> 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.
> 
> It is a bug in the code.
> 
> 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.

Note that the problem may not impact anyone in
the real world.

I am simulating thousands of independent users using keep alive
with a single simulator not using keep alive.

It could very well be the case that the problem only arise for
the simulator and not for the real users.

Still weird though.

Arne