memory

https://drupal.psu.edu/content/memory-profiling-hooks

Wanted to post this to this group as well about my investigation into the memory used by drupal's various hooks in a site that I'm developing. As a result of the monitoring I was able to find ways to either eliminate or mitigate many RAM zapping functions and hooks as well as finding ways to mitigate some other functions (like optimizing the core book module's navigation rendering capabilities).

I used this dropbucket of functions to do the profiling w/ devel to dpm the output dropbucket.org/node/2036

I have a Drupal 6.19 site that also links to some mobile app via custom resources written using Drupal Services 3.x module.

I have set php memory limit to 512M. The site works fine without any memory issues.

However, because the mobile app fires 4-5 concurrent web services requests as a burst, a single app running can apprently cause my server to run out of memory and return a 500 Internal Server Error. The log shows this error:
Cannot allocate memory: couldn't create child process: /opt/suphp/sbin/suphp for /home/cmadmin/public_html/drupal/index.php

Tjo

Tänkte dra igång en liten diskussion här, och hoppas att många lägger äggskeden åt sidan för att dela med sig av sina erfarenheter.

Jag har tänkt en del på minnesutnyttjande och vad man kan göra för att Drupal ska flyta så bra som möjligt. För att göra det enkelt kan jag dra ett exempel som jag diskuterade med några vänner i helgen.

I've been having some occasional trouble where my site slows to a crawl.

Does anyone have any best practices for optimizing Drupal on lower memory configurations.

After a Drupal install has been used a while, the table 'variable' overflows with values set by various disabled modules or obsolete functions which do need clearing because variable_init() (bootstrap.inc) does that unfortunate step of caching all of the table, which then often causes sites to crash due to lack of PHP memory.

Module developers may choose to use functions alternative to variable_set() and variable_get() provided by http://drupal.org/project/queryable_variables but that does not solve the pollution in all the existing 'variable' tables.

I have created a low memory version of system.module for Drupal 6.10 which can be found here. I found it gave a modest performance improvement with low load performance testing on my development machine. Where it shines is under high load relative to tight memory conditions.

With ab -c 100 -n 1000 http://example.com/user on a real site, applying this patch gave somewhere between 18 and 40% reduction in average time per request.

Hello I have a problem with my site when trying to use a RAM Disk to boost temp table create performance. I heard that this optimization was being done on drupal.org but couldn't find any documentation on it. I would appreciate if you could look at my post here and give me any suggestions:

http://drupal.org/node/369204

I create a 5.2 and 6.x patch for measuring how much memory a module takes, and also how much the whole Drupal page load takes.

The results are published here: Measuring memory consumption by Drupal bootstrap and modules.

Short version: in Drupal 6, modules are better off than in 5.2, but the bootstrap is a tad larger.

If anyone is interested in replicating the results with more realistic install profiles, please do so and publish your results/findings/recommendations.