[Info-vax] Apache + mod_php performance

[Dave Froble]

On 9/27/2024 9:11 PM, Arne Vajhøj wrote:
> On 9/27/2024 8:38 PM, Dan Cross wrote:
>> 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.
>
> That is correct.
>
> The client was not using keep alive.
>
> But the server was configured to support keep alive.
>
> Turning that capability off on the server solved the performance
> problem.
>
> No changes on client.
>
> No keep alive used before - no keep alive used after.
>
> Just disabling the capability on the server.
>
>> 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 rather uninteresting number.
>
> But easy to test. It obviously vary a bit, but they
> are all in the 50-100 millisecond range.
>
>>> It is a bug in the code.
>>
>> The evidence in hand is insufficient to make that claim.
>
> I believe that server config supporting keep alive
> causing performance to drop to 1/10'th for clients
> not using keep alive is a bug.
>
> Arne
>

Feature ...

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David Froble                       Tel: 724-529-0450
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