RE: Moving ExecCGI to mod_perl - performance and custom 'modules' [EXT]

Steven Haigh <[email protected]>
Newsgroups gmane.comp.apache.mod-perl
Message-ID <[email protected]>
In fact, I just realised that 'ab' test is rather restrictive.... So 
here's a bit more of an extended test:

# ab -k -n 1000 -c 32

Apache + ExecCGI:
	Requests per second:    14.26 [#/sec] (mean)
	Time per request:       2244.181 [ms] (mean)
	Time per request:       70.131 [ms] (mean, across all concurrent 
requests)

Apache + mod_perl (ModPerl::PerlRegistry):
	Requests per second:    132.14 [#/sec] (mean)
	Time per request:       242.175 [ms] (mean)
	Time per request:       7.568 [ms] (mean, across all concurrent 
requests)

Interestingly, without Keepalives, the story is much the same:

# ab -n 1000 -c 32

Apache + ExecCGI:
	Requests per second:    14.15 [#/sec] (mean)
	Time per request:       2260.875 [ms] (mean)
	Time per request:       70.652 [ms] (mean, across all concurrent 
requests)

Apache + mod_perl (ModPerl::PerlRegistry):
	Requests per second:    154.48 [#/sec] (mean)
	Time per request:       207.140 [ms] (mean)
	Time per request:       6.473 [ms] (mean, across all concurrent 
requests)

Running some benchmarks across various parts of my site made me realise 
I also had some RewriteRules in the apache config that still had 
H=cgi-script - changed those to H=perl-script and saw similar 
improvements:

	ExecCGI - Requests per second:    11.84 [#/sec] (mean)
	mod_perl - Requests per second:    130.97 [#/sec] (mean)

That's quite some gains for a days work.

--
Steven Haigh

📧 [email protected] <mailto:[email protected]>
💻 https://www.crc.id.au <https://www.crc.id.au/>

On Sun, Feb 7, 2021 at 23:58, Steven Haigh <[email protected]> wrote:
> Interestingly, I did get things working with ModPerl::PerlRegistry.
> 
> What I couldn't find *anywhere* is that the data I was loading in 
> Template Toolkit was included in the file in the __DATA__ area - 
> which causes mod_perl to fall over!
> 
> The only way I managed to find this was the following error in the 
> *system* /var/log/httpd/error_log (didn't show up in the vhost 
> error_log!):
> 	readline() on unopened filehandle DATA at 
> /usr/lib64/perl5/vendor_perl/Template/Provider.pm line 638.
> 
> Took me a LONG time to find a vague post that reading in lines from 
> <DATA> kills mod_perl. Not sure why - but I stripped all the 
> templates out and put them in a file instead and re-wrote that bit of 
> code, and things started working.
> 
> I had to fix a few lib path issues, but after getting my head around 
> that, most things seem to work as before - however I don't notice 
> much of an improvement in execution times, I do see this improvement 
> using 'ab -n 100 -c32':
> 
> 	Apache + ExecCGI: Requests per second:    13.50 [#/sec] (mean)
> 	Apache + mod_perl: Requests per second:    59.81 [#/sec] (mean)
> 
> This is obviously a good thing.
> 
> I haven't gotten into the preload or DBI sharing yet - as that'll end 
> up needing a bit of a rewrite of code to take advantage of. I'd be 
> open to suggestions here from those who have done it in the past to 
> save me going down some dead ends :D
> 
> --
> Steven Haigh
> 
> 📧 [email protected] <mailto:[email protected]>
> 💻 https://www.crc.id.au <https://www.crc.id.au/>
> 
> On Sun, Feb 7, 2021 at 12:49, James Smith <[email protected]> wrote:
>> As welsey said – try Registry, that was the standard way of using 
>> mod_perl to cache perl in the server  – but your problem might be 
>> due to the note in PerlRun…
>> 
>> <https://perl.apache.org/docs/2.0/api/ModPerl/PerlRun.html#Description>
>> META: document that for now we don't chdir() into the script's dir, 
>> because it affects the whole process under threads. 
>> ModPerl::PerlRunPrefork 
>> <https://perl.apache.org/docs/20/api/ModPerl/PerlRunPrefork.html> 
>> should be used by those who run only under prefork MPM.
>>  {tbh most people don’t use mod perl under threads anyway as there 
>> isn’t really a gain from using them}
>> 
>>  It suggests you use ModPerl/PerlRunPrefork – as this does an 
>> additional step to cd to the script directory – which might be 
>> your issue….
>> 
>> 
>> 
>> *From:*Steven Haigh <[email protected]>
>> *Sent:* 07 February 2021 01:00
>> *To:* [email protected]
>> *Subject:* Moving ExecCGI to mod_perl - performance and custom 
>> 'modules' [EXT]
>> 
>> 
>> 
>> Hi all,
>> 
>> 
>> 
>> So for many years I've been slack and writing perl scripts to do 
>> various things - but never needed more than the normal apache 
>> +ExecCGI and Template Toolkit.
>> 
>> 
>> 
>> One of my sites has become a bit more popular, so I'd like to spend 
>> a bit of time on performance. Currently, I'm seeing ~300-400ms of 
>> what I believe to be execution time of the script loading, running, 
>> and then blatting its output to STDOUT and the browser can go do its 
>> thing.
>> 
>> 
>> 
>> I believe most of the delay would be to do with loading perl, its 
>> modules etc etc
>> 
>> 
>> 
>> I know that the current trend would be to re-write the entire site 
>> in a more modern, daemon based solution - and I started down the 
>> Mojolicious path - but the amount of re-writing to save 1/3rd of a 
>> second seems to be excessive
>> 
>> 
>> 
>> Would I be correct in thinking that mod_perl would help in this case?
>> 
>> 
>> 
>> I did try a basic test, but I have a 'use functions' in all my 
>> scripts that loads a .pm with some global vars and a lot of common 
>> subs - and for whatever reason (can't find anything on Google as to 
>> why), none of the subs are recognised in the main script when loaded 
>> via ModPerl::PerlRun.
>> 
>> 
>> 
>> So throwing it out to the list - am I on the right track? wasting my 
>> time? or just a simple mistake?
>> 
>> 
>> 
>> --
>> 
>> Steven Haigh 📧[email protected] 
>> <mailto:[email protected]>💻https://www.crc.id.au [crc.id.au] 
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.crc.id.au_&d=DwMFaQ&c=D7ByGjS34AllFgecYw0iC6Zq7qlm8uclZFI0SqQnqBo&r=oH2yp0ge1ecj4oDX0XM7vQ&m=bosoTbkecbnrPukObNK-5Duc1p3JTllIM7_FHhBYKW4&s=vQDi0ezyEZDOz86GVraerPdT76UjN2in3UdPh8fglRM&e=>
>> 
>>  -- The Wellcome Sanger Institute is operated by Genome Research 
>> Limited, a charity registered in England with number 1021457 and a 
>> company registered in England with number 2742969, whose registered 
>> office is 215 Euston Road, London, NW1 2BE.
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