File descriptors

JINMEI Tatuya / 神明達哉 Jinmei_Tatuya at
Tue Feb 24 19:32:46 UTC 2009

At Tue, 24 Feb 2009 13:14:27 -0500,
Todd <canadaboy at> wrote:

> We ran into an issue this morning with some caching DNS servers.  One
> of the zones we heavily rely on was having DNS issues, which appears
> to have been causing very slow responses to us.  The servers in
> question handle about 500queries/second.
> These particular servers are configured with "recursive-clients 5000",
> which we thought would be sufficient.  However, before we even reached
> 5000, the server started boinking because of "socket: too many open
> file descriptors" errors in syslog.
> So, the question is, do we need a 1:1 mapping of fle descriptors to
> max queries, + overhead for named?  From reading, I see that a socket
> uses a file descriptor, so my assumption is yes, but I wanted to check
> with Those Who Are Wiser Than I before I write a change ticket to get
> these things fixed.
> If I do need to allow more file descriptors, what is the best method
> to ensure that the named process has an appropriate number?

Before answering the questions: which version of BIND (you didn't even
say it was a BIND, but I guess it is for the obvious reason:-) are you

JINMEI, Tatuya
Internet Systems Consortium, Inc.

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