Re: mystery NCSA httpd problems on

Jonathan Magid (
Sun, 29 Jan 1995 02:52:47 +0100

On Sat, 28 Jan 1995, Rob McCool wrote:
> To change your queue size, you need to change the kernel's maximum
> connection request size. Under BSD, this parameter is called
> SOMAXCONN. Since you're using Solaris, you can use the ndd command to
> set your maximum queue size higher. The parameter you want to
> experiment with is tcp_conn_req_max.
> Finally, you have to change your server software to use a larger queue
> size. The NCSA httpd, if I remember correctly, uses a queue size of
> 5. Search for a call to listen() and experiment with the value.
> If anyone else has more data on this problem, we'd love to hear about
> it. I hope this helps anyone who is having similar problems with their
> servers. I heard a rumor that these problems are being caused somehow
> by routing, Sprint and MCI. Anybody know more?

We're having the same problem on sunsite with NCSA 2.3 and Solaris 2.4.

Seems like all the big servers are encountering it... sigh. We're in
touch with the Solaris TCP development team and they're working on it.

Unfortunately tcp_conn_req_max has a maximum value of 32 under solaris...
I'll tell you more as I learn it (and forward this to the engineers at sun)


--\/SunSITE admin