named crashing with too many open files

[Ben Stern]

On Fri, Oct 27, 2000 at 11:33:51PM +0100, Jim Reid wrote:
> This doesn't mean a thing. It's quite common for some folk's name
> servers to be unreachable. Your name server will not specially create
> a unique socket (file descriptors) when sending UDP queries to another
> server. It uses one socket for all outbound queries. This means file
> descriptors should get used up talking to those unreachable
> servers. However named could use a file descriptor for each TCP
> connection it tries to initiate to those dead/unreachable servers. But
These are TCP connections.

> those descriptors would be recycled after a few minutes when the TCP
> connections fail and their PCBs get torn down. And anyway it would
> take an awful lot of zone transfers requests or truncated replies from
> those servers - TCP traffic - to account for file descriptor
> exhaustion.
I know - that's why I'm confused.  It *is* opening a few hundred TCP
connections to these servers.

> How do you *know* it's wasting open files on these dead hosts? Where's
> the proof? If this really is the problem - I doubt it - then you can
> use server{} statements to mark them as bogus. And if their IP
Testing that right now.

> addresses are listed in zone{} statements, you could remove them.
> What did lsof have to say about the descriptors named was using?
Either ESTABLISHED - which I don't get, since I cannot telnet to that's
server's port 53, or CLOSE_WAIT.

> Could you have lots of inbound TCP connections to the name server, ie
> lots of incoming zone transfer requests?
It's a possiblity.  None of these servers are actually listed in the
named.conf, other than the bogus statements I added, so they may be flooding
it.

Thank you!
Ben Stern