Question APC and vb datastore filecache question

[jdougher]

I have vboptimise configured to use APC. Given this, what is the optimal way to set up the config.php file?

What I find subjectively is that the forum works fastest when $config['Datastore']['class'] = 'vB_Datastore_Filecache'; is enabled

However, when this is enabled, the style chooser at the bottom of the forum disappears. This apparent bug has been confirmed by other users on vbulletin. This occurs with both PHP 5.2.14 and 5.3.24 (the latter of which I am currently running).

If I disable the vb datastore filecache, the style chooser returns.

However, if I then enable the $config['Datastore']['class'] = 'vB_Datastore_APC'; in config.php, performance deteriorates.

Any suggestions?

Thanks.

 

[Fillip H.]

I've never heard reports of any performance detriment while using that config flag - we use it on this forum.

I'll run some tests here on DBT to see if there's any noticeable difference for us - if there is, then it does seem like a bug in vB.

 

[Fillip H.]

Update

Here's our results for load time tests on forum.php here on DBT:


With vB_Datastore_APC
Avg 1.75865 seconds

Without vB_Datastore_APC
Avg 3.05970 seconds

 

[jdougher]

If vboptimise is configured to use APC, as it is on my forum, is the vB_Datastore_APC setting in config.php even necessary? Required? What happens if I comment that out and comment out the datastore filecache?

 

[Fillip H.]

Our vB Optimise is also configured to use APC, and as you can see by those results we suffer almost a doubling of page load times if we comment out the vB_Datastore_APC from config.php.

I cannot give you any more information than that; a properly configured APC installation with enough memory allocated being added to config.php has a significant performance improvement for us.

 

[jdougher]

How much memory should be allocated on a server machine with 8 gigs of RAM? And exactly how do I allocate the memory? Thanks.

 

[Fillip H.]

Here's the relevant parts of our php.ini file - we're also running 8GB RAM:

apc.shm_size = 512M
apc.max_file_size = 2M
apc.ttl = 7200
apc.user_ttl = 7200
apc.cache_by_default = 0

If you check your AdminCP's View PHP Info page and look for the section called Scan this dir for additional .ini files - if that has a value (for us it's /usr/local/lib/php.ini.d) I recommend making a new file in there called apc.ini (making the full path /usr/local/lib/php.ini.d/apc.ini) and use the above contents in there.

Otherwise, just place it at the end of your php.ini file.

 

[jdougher]

Thanks for those settings.

A different/related issue:

My host, when upgrading PHP to 5.3.x, forgot to reinstall APC. He did that just now, but now vboptimise gives this message when I click "system test":

vB Optimise is currently offline. Please enable and configure vB Optimise to run a system test.

It's turned on under Main Settings.

 

[Taurus]

I am sorry to jump in here, but this might be something that is not set up correctly for me too. I know I am on vb4, but so are you guys from dbtech. This is what my config.php is looking like now:

// ****** DATASTORE CACHE CONFIGURATION *****
// Here you can configure different methods for caching datastore items.
// vB_Datastore_Filecache - to use includes/datastore/datastore_cache.php
// vB_Datastore_APC - to use APC
// vB_Datastore_XCache - to use XCache
// vB_Datastore_Memcached - to use a Memcache server, more configuration below
// $config['Datastore']['class'] = 'vB_Datastore_Filecache';

// ******** DATASTORE PREFIX ******
// If you are using a PHP Caching system (APC, XCache, eAccelerator) with more
// than one set of forums installed on your host, you *may* need to use a prefix
// so that they do not try to use the same variable within the cache.
// This works in a similar manner to the database table prefix.
// $config['Datastore']['prefix'] = '';

// It is also necessary to specify the hostname or IP address and the port the server is listening on
/*
$config['Datastore']['class'] = 'vB_Datastore_Memcached';
$i = 0;
// First Server
$i++;
$config['Misc']['memcacheserver'][$i] = '127.0.0.1';
$config['Misc']['memcacheport'][$i] = 11211;
$config['Misc']['memcachepersistent'][$i] = true;
$config['Misc']['memcacheweight'][$i] = 1;
$config['Misc']['memcachetimeout'][$i] = 1;
$config['Misc']['memcacheretry_interval'][$i] = 15;
*/

I have APC set up, so do I need to edit something on the above?

Thank you!

 

[Fillip H.]

Thanks for those settings.

A different/related issue:

My host, when upgrading PHP to 5.3.x, forgot to reinstall APC. He did that just now, but now vboptimise gives this message when I click "system test":

vB Optimise is currently offline. Please enable and configure vB Optimise to run a system test.

It's turned on under Main Settings.

Try re-saving it with the Filecache operator, run test again, then switch it back to APC and rerun the test.

I am sorry to jump in here, but this might be something that is not set up correctly for me too. I know I am on vb4, but so are you guys from dbtech. This is what my config.php is looking like now:

// ****** DATASTORE CACHE CONFIGURATION *****
// Here you can configure different methods for caching datastore items.
// vB_Datastore_Filecache - to use includes/datastore/datastore_cache.php
// vB_Datastore_APC - to use APC
// vB_Datastore_XCache - to use XCache
// vB_Datastore_Memcached - to use a Memcache server, more configuration below
// $config['Datastore']['class'] = 'vB_Datastore_Filecache';

// ******** DATASTORE PREFIX ******
// If you are using a PHP Caching system (APC, XCache, eAccelerator) with more
// than one set of forums installed on your host, you *may* need to use a prefix
// so that they do not try to use the same variable within the cache.
// This works in a similar manner to the database table prefix.
// $config['Datastore']['prefix'] = '';

// It is also necessary to specify the hostname or IP address and the port the server is listening on
/*
$config['Datastore']['class'] = 'vB_Datastore_Memcached';
$i = 0;
// First Server
$i++;
$config['Misc']['memcacheserver'][$i] = '127.0.0.1';
$config['Misc']['memcacheport'][$i] = 11211;
$config['Misc']['memcachepersistent'][$i] = true;
$config['Misc']['memcacheweight'][$i] = 1;
$config['Misc']['memcachetimeout'][$i] = 1;
$config['Misc']['memcacheretry_interval'][$i] = 15;
*/

I have APC set up, so do I need to edit something on the above?

Thank you!

You don't need to change anything in the config.php file. You may or may not receive a performance increase or decrease by changing

// $config['Datastore']['class'] = 'vB_Datastore_Filecache';

to

$config['Datastore']['class'] = 'vB_Datastore_APC';

 

[Taurus]

OMG man....that made such a huge difference in speed!!! Why did no one tell me this before? Changing my config.php file to this:

$config['Datastore']['class'] = 'vB_Datastore_APC';

really almost doubled my loading speed....man.....I am so excited now!! Thank you so much!!!!

 

[jdougher]

OMG man....that made such a huge difference in speed!!! Why did no one tell me this before? Changing my config.php file to this:

$config['Datastore']['class'] = 'vB_Datastore_APC';

really almost doubled my loading speed....man.....I am so excited now!! Thank you so much!!!!

Total mystery. This setting definitely slows my site down. Any idea of why?

 

[jdougher]

Try re-saving it with the Filecache operator, run test again, then switch it back to APC and rerun the test.

You don't need to change anything in the config.php file. You may or may not receive a performance increase or decrease by changing

// $config['Datastore']['class'] = 'vB_Datastore_Filecache';

to

$config['Datastore']['class'] = 'vB_Datastore_APC';

The APC issue was a host issue. That's fixed now. However, the "filecache" option in config.php with vboptimise set up to use APC is definitely the fastest setting. I don't know why. Unfortunately, it results in the missing style chooser that I mentioned earlier on.

Any idea of why enabling the APC setting in config.php results in the slowdown? Users notice it. Could it be an APC configuration issue or parameter?

 

[Fillip H.]

If you're using the settings I suggested in a previous post then I can't see how it can be a configuration issue as you shouldn't run out of memory (a cache configured without enough memory allocated can be a severe detriment to performance and/or cause random issues across the site).

Attached is a plugin (not a product) that will show you information regarding your APC configuration on the main ACP page - if there's any issues with memory allocation it will show in the form of "cache full count" being greater than 0.

If everything seems fine in that regard, then I'm officially out of ideas - I don't know enough about these systems to tell beyond that.