Task #54990

Epic #55070: Workpackages

Epic #55065: WP: Overall System Performance (Backend and Frontend)

Story #55073: review autoloader and language cache

ClassLoader cache ist too slow, no matter which CF Backend is used

Added by Rupert Germann about 6 years ago. Updated over 2 years ago.

Status:
Closed
Priority:
Should have
Assignee:
-
Category:
Performance
Target version:
6.2.0
Start date:
2014-01-14
Due date:
% Done:

0%

TYPO3 Version:
6.2
PHP Version:
5.4
Tags:
Complexity:
Sprint Focus:

Description

while Profiling a 6.2 installation with XHProf I found that the most expensive part of the request is always the classloader cache - no matter which CF backend is used for it.

the attached callgraphs both show the delivery of a cached page, one with the default configuration (simple file backend) and one with the classloader cache Backend set to memcached.

In both cases we see that either file_get_contents() or Memcach::get() is the most expensive function.

the request times (mesured with the adminPanel) are almost the same in both cases: ~155ms with simple file backend and 150 ms with memcache

Since memcache should be way faster than the filesystem I think there's a lot of room for optimizing in the classloader.

callgraph_filesystem.png View (2.83 MB) Rupert Germann, 2014-01-14 16:54

callgraph_memcached.png View (2.23 MB) Rupert Germann, 2014-01-14 16:54

Related issues

Related to TYPO3 Core - Bug #55029: Class Loader fails if entry in class cache is discarded Closed 2014-01-15

History

#1 Updated by Markus Klein about 6 years ago

  • Parent task set to #52949

#2 Updated by Helmut Hummel about 6 years ago

Hi Rupi,

Rupert Germann wrote:

Since memcache should be way faster than the filesystem I think there's a lot of room for optimizing in the classloader.

I'm looking at the graph and the code and really asking myself where the room is for optimizing. Given the cache is populated, the code is pretty straightforward and only does 3 things:

  1. lookup the cache entry
  2. get the cache entry
  3. require the class file

Can you elaborate how this could be optimized?

#3 Updated by Helmut Hummel about 6 years ago

Rupert Germann wrote:

In both cases we see that either file_get_contents() or Memcach::get() is the most expensive function.

The memcache backend is also not optimal here. Can you check the performance with an APC backend?

#4 Updated by Helmut Hummel about 6 years ago

Numbers from my Server for incl wall time of loadClass

  1. SimpleFileBackend: 61,557
  2. ApcBackend: 23,505

APC is roughly 3 times faster

#5 Updated by Helmut Hummel about 6 years ago

  • Status changed from New to Needs Feedback

#6 Updated by Helmut Hummel about 6 years ago

  • Status changed from Needs Feedback to New

#7 Updated by Ingo Schmitt about 6 years ago

  • Parent task changed from #52949 to #55073

#8 Updated by Ingo Schmitt about 6 years ago

  • Category set to Performance

#9 Updated by Rupert Germann about 6 years ago

Yes, indeed APC is way faster here.
But the point is: I don't want to use accelerators just to make a site usable.
In case I really need an accelerator because my site has a huge load than I'm already out of options.

#10 Updated by Mathias Schreiber about 5 years ago

  • Status changed from New to Resolved

composer classloader solves this

#11 Updated by Riccardo De Contardi over 2 years ago

  • Status changed from Resolved to Closed

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