Conference turris::digital_unix

9471.0. "socket buffer question" by USCTR1::16.178.0.161::BENGHUI () Thu Apr 10 1997 23:15

Hi,

I have this proxy application (Harvest) that is taking up
~433M of memory, of which, ~350M is resident.

According to tools provided, ~250M is accountable for 
the application data. That left with ~100M of memory
that is missing. The proxy server is pretty busy with
maybe a thousand sockets active at any instance, of 
which approx 250 sockets are in EST state.

Couples of question here...

1) Is it possible that this ~100M of memory is used as 
   socket buffer (32K tx and 32K rx) ?
   Since ~1000 sockets translate to ~64M of socket buffer.

2) Is socket buffer allocated in user space or kernel space ?
   I suspect it is in user space because the resident size
   of the kernel is only ~35M.

3) Is this socket buffer free after the socket close() call or 
   after the tcp connection has finish the FIN exchange ?

Please advise... will provide further information if required.

    vmstat -M will show you all of the kernel memory consumed, which
    includes sockets, socket buffers, etc.
    
    vmstat 1 will give a 1 second running snapshot of total memory
    in use, including free memory.  You could include both of those
    command outputs here so we can evaluate your particular memory usage.
    
    John