Please help - Hitting hard memory limit of 53.215232MB - Using Single PHP.INI and verified to 128M

I encountered something similar in hostgator. They have set PHP memory_limit to 64M by default. Drupal's admin/reports/status page agrees that it is 64M. However, admin/build/modules gives me a blank page and PHP logs "PHP Fatal error: Out of memory (allocated 41418752) (tried to allocate nn bytes)". The obvious question is "why 40M"?

I got an answer saying that the cause is that I have hit one of Apache's limits, which are:

RLimitMEM 83886080 104857600 (which covers all Apache memory needs)
RLimitCPU 150 200
RLimitNPROC 25 30

Of course what interests me here is what that means in practice. If, as I suspect, Apache is never going to allow more than 40M PHP memory, then the 64M setting is meaningless, hence misleading. I am still talking with tech support (in case the limit is the CPU or the number of processes).

--------- An update:

I verified that in my case, with php memory_limit=64M and with RLimitMEM set to 80M in Apache, only about 40M were left for php web scripts:

// phpmemory.php

ini_set('memory_limit', '64M');

print 'Base: ' . memory_get_usage() . '<br />';
$pattern = str_repeat("0123456789", 1000);

print 'Clear: ' . memory_get_usage() . ' | ';
$fill = str_repeat($pattern, 1000);
print '1000 x 10000 chars: ' . memory_get_usage() . '<br />';

unset($fill);
print 'Clear: ' . memory_get_usage() . ' | ';
$fill = str_repeat($pattern, 2000);
print '2000 x 10000 chars: ' . memory_get_usage() . '<br />';

unset($fill);
print 'Clear: ' . memory_get_usage() . ' | ';
$fill = str_repeat($pattern, 3000);
print '3000 x 10000 chars: ' . memory_get_usage() . '<br />';

unset($fill);
print 'Clear: ' . memory_get_usage() . ' | ';
$fill = str_repeat($pattern, 4000);
print '4000 x 10000 chars: ' . memory_get_usage() . '<br />';

unset($fill);
print 'Clear: ' . memory_get_usage() . ' | ';
$fill = str_repeat($pattern, 5000);
print '5000 x 10000 chars: ' . memory_get_usage() . '<br />';

Output:

Base: 64036
Clear: 74284 | 1000 x 10000 chars: 10074344
Clear: 74416 | 2000 x 10000 chars: 20074428
Clear: 74416 | 3000 x 10000 chars: 30074428
Clear: 74416 | 4000 x 10000 chars: 40074428
Clear: 74416 | 
Fatal error: Out of memory (allocated 262144) (tried to allocate 50000001 bytes) 

Probably only an non-web php script can use all 64M of php memory.
They agreed to raise the RLimitMEM for a subdomain and it did work.

To see the memory_limit which Drupal is actually picking you can
- check the admin/reports/status page (in Drupal 6)
- run <?php phpinfo(); ?> inside a Drupal post using the "PHP code" input format (in Drupal 5).

The error message says that it hit a memory limit of about 50M, which may be due to the RLimitMEM settings in Apache that I mentioned.

The simple script which I used above was my natural response when I was given the "Contact Drupal's technical support" speech. I said "Hey, forget about Drupal and try this instead".

I had a browser open to /admin/modules in another computer, so I went there and turned off a bunch of modules, and selected CiviCRM again. I'm not sure that anything I did actually addressed the problem, but now I'm not getting the error.

It is well-advised to leave a separate browser open to the modules window so you can recover... turning off modules if you have to.

I think they are getting more calls on this issue. The last support guy immediately knew what I was talking about, and confirmed that they won't go to 128M. He got irritated when I pushed him to ask management to consider lifting the limit. I'm not going to blame him for being caught between me and Corporate policy, and frankly, Bluehost is a bit higher than others, not to mention the fact that I've always got good service from them.

ANhosting tech support claimed 20M and their sales guy said definitively 12M... Either of those are low for Drupal, and ANhosting claims to be good Drupal support people.

On the Drupal and CiviCRM side, the developers need to be careful of memory usage.

On the hosting side, we need ratings on php memory_limits for the different hosts. It is a competitive world. If a hosting company gets a reputation for not delivering the services that Drupal requires, they could lose a whole class of webdesigners.