Well, with little knowledge I have about mod_perl
if sys admin tells you that mod_perl slows down
the system, before making changes to the program
you should have at least the following:
a) Memory utilization numbers (sorted by a process)
b) CPU utilization numbers (sorted by a process)
c) Whether there is any process locks any file for more then a second
d) If you access the dabase you need statics for what
the db engine is doing
e) you also need to know whether the network requests that your
program makes are being handled immediately by other servers
f) you should profile your application and see if the numbers
from the profile correlate to overall system utilization statistics
that you obtained in steps above.
g) you should also be able to determine things like:
how often perl has to recompile a module. Are you regular expressions
being evaluated every time when executed.
Once you get all that information, this list may be able to help
you in deciding what and how to optimize.
Performance tuning is a science on its own (a little one :-) ) and
there are a lot of details to be considered there.
Regards,
Vladislav
On 23-Jun-2000 Vladislav Safronov wrote:
> Hi, ( ili privet )
>
> I was looking any tips and tricks to optimize my perl script since,
> our sysadm tells that it's mod_perl slow down the web server
> response time and it should be rewritten in C. This script
> does use any database connection, so I think threre is no real way to
> speed it up. Posting message here was the last chance.
>
> Vlad.
>
> pishite po-russki.
>
>> -----Original Message-----
>> From: [EMAIL PROTECTED]
>> [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED]
>> Sent: Saturday, June 17, 2000 9:24 PM
>> To: Vladislav Safronov
>> Cc: [EMAIL PROTECTED]
>> Subject: RE: Highly optimized mod_perl ?
>>
>>
>> Hi,
>>
>> There was a discussion on this list about
>> 1.5 weeks ago on how to optimize mod_perl
>> execution when using the database. Stas
>> Bekman basically has done some tests to
>> show that the driver needs to be initialized
>> in startup.pl file.
>>
>> There were also a discussion about the fact
>> that as far as using templates for HTML
>> generation the fastest approach is when
>> a template is compiled into perl code
>> before being executed. I do not have
>> enough understanding of the internals to
>> explain why though.
>>
>> Another discussion suggested that it is
>> much better to precompile explicitly
>> the functions that you need to use
>> in modules like CGI.pm instead. The
>> fact that you precompile specific functions
>> and not the whole module will save memory
>> space of apache processes that run mod_perl.
>> Saved memory means less swaping, and more
>> memory for cache -- that means speed.
>>
>> There was also a post referring to a comparasing
>> between many scripting and compiled languages
>> that pointed out that by far the most
>> important factor when choosing a language
>> to implement a taks is what algorithm is
>> being used (ie. how smart and fast it is)
>> and that differences in programming languages
>> are not significant compared to that.
>>
>> I also just recently read in "Advanced Perl Programming"
>> by Sriram Srinivasan that (on page 369)
>> there are Static Typing Hints:
>> they give hints to the interepreter for better optimization
>> and type checking.
>> so
>> my Dog $spot = new Dog;
>> should be faster
>> then
>> my $spot= new Dog;
>>
>> It actually should be faster for the consequent method calls
>> to $spot->xyz (because perl would not have to do type checking
>> and run-time)
>> (this me parapharsing the example from the book
>>
>> Static hints will also allow for more aggressive compiler
>> optimizations
>> (using perlcc) (but I do thing this mod_perl relevant).
>>
>> This is my high level overview of what I have learned sofar
>> from the list (I am new to Perl so I am just trying to absorb
>> as much as possible).
>>
>> Regards,
>> Vladislav P.
>>
>>
>>
>>
>>
>>
>> On 17-Jun-2000 Vladislav Safronov wrote:
>> > Hi!
>> >
>> > Does anyone know the way to highly optimize mod_perl for speed?
>> > Any hacks, advices? All standard advices read from help are done...
>> >
>> > Best regards,
>> >
>> > Vlad Safronov,
>> > mailto: [EMAIL PROTECTED]
>>
