Site freeze when i start the admin Magento
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I have really strange behavior.
The site is really fast. I have created a script to check every second what the speed of the website.
The results.

FAST - 17:41:54: 0.287875890732
FAST - 17:41:55: 0.311651945114
FAST - 17:41:57: 0.264428138733
FAST - 17:41:58: 0.304912805557
FAST - 17:42:00: 0.321930885315
FAST - 17:42:01: 0.29382109642
FAST - 17:42:02: 0.289844989777
FAST - 17:42:04: 0.278220891953
FAST - 17:42:05: 0.31251001358
FAST - 17:42:07: 0.285416126251
FAST - 17:42:08: 0.290918111801
FAST - 17:42:09: 0.332083940506
FAST - 17:42:11: 0.266509056091
FAST - 17:42:12: 0.281701803207
FAST - 17:42:14: 0.275447845459

I'm very happy with the speed.
But i have persistent problem and i have no idea where to look to fix this problem.
At the moment a start the admin the site totally freezes.

The results
SLOW - 20:50:56: 2.04331302643
SLOW - 20:51:10: 12.8588819504
SLOW - 20:51:23: 12.3065569401
FAST - 20:51:25: 0.452680110931
FAST - 20:51:27: 0.337702989578
FAST - 20:51:28: 0.332473993301
SLOW - 20:51:42: 12.5140118599
SLOW - 20:53:43: 120.119220972
FAST - 20:53:45: 0.508615016937
FAST - 20:53:47: 0.520901203156
SLOW - 20:54:05: 16.9637360573
SLOW - 20:55:20: 73.9818410873
SLOW - 20:55:36: 14.3260159492
SLOW - 20:56:08: 30.5557489395
SLOW - 20:57:51: 102.450763941
FAST - 20:57:53: 0.282537937164
FAST - 20:57:55: 0.493069887161
FAST - 20:57:56: 0.322154998779
SLOW - 20:57:59: 2.06928992271
SLOW - 20:58:03: 2.24757194519
SLOW - 20:58:06: 2.02194190025
FAST - 20:58:10: 1.7101111412

As you can see i have some loads that are more then 100 sec. The strange thing i get no errors at all.

The site is running on dedicated server with memcache and apc. What i have already done to try to fix this problem.

- Flush cache/Memcache APC.
- Restart the server
- Reindex all data
- Checking for bugs
- Try some debug tools to find the problem

I have no idea where a have to search to find the problem.

The only thing what i have not done is remove all the sessions in the database.
Is there differten between sessions on the frontend and sessions in the admin?

My question is: Are there any tools/extensions to find the problem so i can fix it?

Hopefully someone has answer for me.

Thank you very much.

Gr,
Lex


