After some more investigations (due to a third crash, and my server unvaillibility) I found something new in the log :
In the same time as all the crashes, I have in my apache2 access.log a lot of concurrent access from the same IP (I think from a bad configured corporate proxy) This may be the root cause
After some more investigations (due to a third crash, and my server unvaillibility) I found something new in the log :
In the same time as all the crashes, I have in my apache2 access.log a lot of concurrent access from the same IP (I think from a bad configured corporate proxy) This may be the root cause