We restart an apache server every day because RAM usage reaches its limit.

Though of value See this serverfault answer, I dont think lowering the MaxClients in the apache configuration is a solution to the unknown root problem.

Can you make sense out of the below data?

Below is an extract of what

$top with M

returns:

20839 www-data  20   0 1008m 359m  22m S    4  4.8   1:52.61 apache2                     
20844 www-data  20   0 1008m 358m  22m S    1  4.8   1:51.85 apache2                     
20842 www-data  20   0 1008m 356m  22m S    1  4.8   1:54.60 apache2                     
20845 www-data  20   0  944m 353m  22m S    0  4.7   1:51.80 apache2  

and then investigating a single process with

$sudo strace -p 20839

returns only this one line, which is cryptic, for me:

restart_syscall(<... resuming interrupted call ...> <unfinished ...>

Any insights? Thanks.