It seems I have a lot of duplicate processes (apache), is it normal ?
This is the output of the htop command on my ubuntu server 12.04 :
Thank you for your advices.
No, it's not weird. Yes, it's normal.
Apache can use multi-processing modules (MPM) to handle concurrent requests (see Apache MPM documentation). The default used in Ubuntu is
If the server was receiving significant traffic, you would see even more processes spawned, but even without traffic there will be several spare processes waiting.