[TYPO3-performance] Backend Performance TYPO3 4.3 - Strange Behavior

[Susanne Moog]

Hey everyone (I hope someone is still active in this list),

I have a strange performance upgrade on one of our websites since we
upgraded to TYPO3 4.3.3 (from 4.2.12).

If I click on a page in the page tree the page module needs between 5
and 15 seconds to render the cols and content. The subsequent requests
to the same page are - most of the time - a lot faster (1-3 seconds).
Same with editing content elements.

I started testing for the cause with cachegrind and found nothing out of
the ordinary, no big performance killers. I had a look at mysql
settings, apache settings, php settings and found nothing.

The only thing I found which seems to be related is in our server
monitoring tool:
- MySQL threads dropped with the update from about 10 average to 1 or 2
average
- netstat dropped with the same rate (from 10 average to 1 or 2) both on
db and file server
- fork rate dropped from 370 average to nearly 0

I am a bit desperate now, as I have no further idea what could cause
this. Has anyone of you perhaps an idea or a similar experience?

Thanks in advance,

Susanne