Re: [PHP4BETA] PHP4b3 RC3 Memory usage

In main.c line 771 (php_request_shutdown function) change the second parameter 0 to a 1. What happens is, we made a change so that memory is cached also between requests and not only for the current request, this change will make it clean the cache each request. This is better for performance but eventually requires more memory. It would change each individuals requests' memory usage though. You can also play around with MAX_CACHED_MEMORY and MAX_CACHED_ENTRIES in zend_alloc.h if you want which control what the maximum size of cached memory is and how many blocks of each size to save. Andi At 12:37 AM 11/11/99 +0100, Chris Chabot wrote:

Ok made the modification as requested, results are: (apache 1.3.9/php4b3 rc4 as described below)

start        reviewboard scripts (after 20000 requests)
1764        7180

So it helped a little bit, but not enough to make a huge difference to the problem as described below.. which makes sence since only one of the global variables is an array .. The thing that freaks me out is that its also not a memory leak either ... the memory used stabalises after about 500 hits and doesnt grow after that (tried this upto 5,000,000 hits during a couple of hours :P). So there's something about either the size of the code base (its a rather large project base, eg 340Kb of php script, 8000 lines of code +), or some other unforseen thing i do in these scripts that freak it out, that worked fine under the 3.x series.... again my offer is open for people (that i can trust) to play around w/ the code base on this box. But since it is a product of the reviewboard magazine, and fully tm'd and C'd, i couldnt send it to ya'll... Anyways hope im able to help out a bit and that we can get this problem solved before php4 final would hit the shelves :)

    -- Chris Chabot

Andi Gutmans wrote: Try and edit zend_compile.h and change #define INITIAL_OP_ARRAY_SIZE 64 to 8. It might help a little bit. Let us know of the results. Andi At 01:13 PM 11/10/99 +0100, Chris Chabot wrote:

Ok ive finaly come around to setting up some test cases.

    These are the 2 different configurations:

        apache 1.3.9 / php 3.0.12

        php conf:

./configure --disable-inline --disable-debug --enable-sysvsem --enable-sysvshm \ --enable-track-vars --with-zlib --with-mysql=/usr/local --with-gettext --with-gd \ --with-ttf --with-apache=../apache_1.3.9

    CFLAGS=-O2

And

        Apache 1.3.9 / php 4b3 RC4

    php conf:

./configure --disable-inline --disable-debug --enable-sysvsem \ --enable-sysvshm --enable-track-vars --with-zlib

--with-mysql=/usr/local \

--with-gettext --with-gd --with-ttf --with-apache=../apache_1.3.9 \ --with-readline --with-ftp --with-mcrypt --with-mhash

    CFLAGS=-O2

Recorded are 3 states. eg startup mem size, mem size after hitting the <? phpinfo(); ?> page a few times (50k times), and after doing a simple mysql query script (that basicly does a count(*) from table, fetches result in a list($count) = mysql_fetch_row($res) statement, and echo's $count. I also included apache bench's requests a second result, to give some insight into php4's normal performance. given the nature of the scripts, they shouldnt differ /to/ much since there both very small scripts where I/O gives more overhead then the scripting envirioment.

            Start                        info 

query

php3     1500                        1868 (no leaks)        1948 (no 

leaks)

reqs/sec 361.41 349.14

php4     1776                        2128 (no leaks)        2208
reqs/sec                               225.99                    343.11

As you can see php4 is performing a little slower on real simple scripts. but its memory usage on the info.html and simplequery.html pages is very respectable. A little higher, ok, but nothing to be upset about. What strikes me weird here is that the info page is so much slower, but i gues php4 just has a lot more cool modules to dump in the info page. Now to do this on the reviewboard code (quite complex, more then 100 variables , and 243 functions in global scope. (20k requests)

php3      5088 (no leaks)

php4      starts at 6208 then grows to around 7340 ... keeps hanging

around that number. As u can see, there's no memory footprint problem with the basic configuration, or basic scripts. But as soon as i unleash some real life big scripts @ it (i tried this w/ other script bases to, same results) the memory usage is substancialy higher then w/ php 3 ... 3 1/3 megs per process extra is a killer for a box with 100 httpd's open ... thats 300 megs of memory dude! :) this would definatly scare me away from an

upgrade....

if there's any other things i can try, or even give Sascha or rasmus access to one of my test boxes to they can play with it (cable modem or t1 connects, dont wurry) let me know.

    -- Chris Chabot

    CTO Reviewboard Magazine

Sascha Schumann wrote:

On Tue, Nov 09, 1999 at 09:57:42AM -0500, Rasmus Lerdorf wrote:

This memory usage issue is definitely something we need to

address. The

Zend parser should be much more efficient with its memory usage

because of

the reference counting, and the various extensions should at worst be using as much memory as PHP 3, so going from 3M to 7M per httpd is a mystery to me. I think we need to do a bit of scientific testing here. Have a simple little script that just does a "Hello World" to

start

with and bang at it with ab or http_load with both PHP 3 and 4. Then make the script do a simple MySQL query and compare the numbers. I'll try to find some time today to do a check on my box to see

if I can

verify your numbers.

    I've just sent the attached email to Chris. The page I
    accessed contained only <?phpinfo()?>, so there is a chance
    that the leak appears only in complex scripts.

--

          Regards,

                            Sascha Schumann
                                 Consultant

------------------------------------------------------------------------

Subject: Re: [PHP4BETA] PHP 4.0b3, second try Date: Tue, 9 Nov 1999 16:10:48 +0100 From: Sascha Schumann <sascha@schumann.cx> To: Chris Chabot <chabotc@reviewboard.com> References: <Pine.LNX.4.04.9911091245580.22365-100000@tjafs.fast.no>

<38282CB8.CBE01F77@reviewboard.com> <19991109151912.A16464@schumann.cx> <382832A7.43210EA0@reviewboard.com>

ps testing tool i use to test these releases is http_load (http://www.acme.com/software/http_load/) i strongly sugest this program to anyone who wants to do some serious

load

testing.

    How large is the process at startup time? If it grows
    drastically during http_load, you probably have found a
    memory leak.

    I've compiled 4.0b3-RC3 with

        CFLAGS="-O2 -march=pentiumpro" \
        ./configure \
            --disable-debug \
            --disable-inline \
            --with-apache=../apache_1.3.9 \
            --with-mysql=/local/mysql

    Apache was compiled then with

        CFLAGS="-O2 -march=pentiumpro" \
        ./configure \
            --prefix=/some/where \
            --activate-module=src/modules/php4/libphp4.a

    Now, on startup the process is a little bit larger than 2MB.
    That includes the complete PHP module. After running 70
    parallel HTTP queries against a PHP-generated page, the
    server process hardly grew in size (+70KB).

    What does your demo page(s) do? Is the effect similar, if the
    only page you access is "<?phpinfo()?>" ?

--

          Regards,

                            Sascha Schumann
                                 Consultant

------------------------------------------------------------------------

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