Hi,

How can I determine the maximum number of simultaneous tcpip connections on
a solaris 10 x86 server ?

when I check via netstat using this command:

netstat -an -P tcp -f inet | wc -l

I get a total of 286 connections, but I thought that the following command
would show me the limit:

ndd  /dev/tcp tcp_conn_req_max_q

the last command results in 128, so this is obvious not the command i'm
looking for, as I'm now getting 286 entries in the connection list.

Any ideas ?

Tom.

Tom Van Overbeke <tomvo@absi.be> wrote:
> netstat -an -P tcp -f inet | wc -l

Leave off the "a".  It's showing you the listening sockets as well.  And
you might want to grep the output for "ESTABLISHED", if you're only 
interested in established (live) connections.

-- 
Brandon Hume    - hume -> BOFH.Ca, http://WWW.BOFH.Ca/

Tom Van Overbeke <tomvo@absi.be> wrote:
> Hi,

> How can I determine the maximum number of simultaneous tcpip connections on
> a solaris 10 x86 server ?

I don't know if there's a particular limit on that....

> when I check via netstat using this command:
> netstat -an -P tcp -f inet | wc -l

> I get a total of 286 connections, but I thought that the following command
> would show me the limit:

> ndd  /dev/tcp tcp_conn_req_max_q

Nope.  This page mentions the parameter:
http://docs.sun.com/app/docs/doc/816-0607/6m735r5ga?a=view

which is associated with a queue for incoming connections.  It's not a
limit on overall connections.

-- 
Darren Dunham                                           ddunham@taos.com
Senior Technical Consultant         TAOS            http://www.taos.com/
Got some Dr Pepper?                           San Francisco, CA bay area
         < This line left intentionally blank to confuse you. >

On 2007-02-27 15:17:08 +0000, "Tom Van Overbeke" <tomvo@absi.be> said:
> 
> ndd  /dev/tcp tcp_conn_req_max_q
> 
> the last command results in 128, so this is obvious not the command i'm
> looking for, as I'm now getting 286 entries in the connection list.


That's not the maximum number of connections, it's the maximum size of 
the connection queue for a particular socket - the maximum number of 
connections that the system will queue on your behalf before you call 
accept() on them.  There is some complexity with pending connections 
which have or haven't completed the TCP handshake.

I have no idea what the system total of (accepted, pending, incomplete 
handshake?) connections is, or if there is one.  I can't see why there 
should be one short of some limit on memory.  Obviously applications 
might want to enforce one, but they can do that by not accepting more 
than they want (and making sure the listen() backlog (which I think the 
above parameter is an upper limit to in some sense) is not too high.

--tim