BIND limitations

[Jim Reid]

>>>>> "martin" == mmartin4072  <mmartin4072 at my-deja.com> writes:

    martin> I need to know if there are any limitations as to the
    martin> number of processes that BIND can run. I would like to
    martin> have a box perform notify and zone transfers for about
    martin> 40000 different zones. Any input would be helpful.

BIND doesn't (need to) care how many processes you can run. The OS
that BIND runs on will have a different idea about that however. BIND8
forks a new process that exec()'s named-xfer for each inbound zone
transfer. If your server does too many of them at once and your name
server process is very big, the operating system might get upset
because all of the swap resources have been used because a 100Mbyte
(say) named process forks N times at once. [To some extent, that
depends on the VM subsystem of the OS.] BIND8 has a default of 10
simultaneous inbound zone transfers, which should be good enough for
most name servers. That default can be changed with the transfers-in
clause in the options{} statement. Whether that limit is OK for you
depends on how big the zones are, how often they change, how long they
take to transfer, how big your named process is and how your OS copes
with multiple forks of a big process, etc, etc.