Zone transfers locking up DNS

[Gary Algier]

Hi,

I am using a well known email blacklist service.  It is implemented with zone
transfers.  When the transfer happens it takes about 5 minutes.   While
this is going on, all other DNS queries stop.  And yes, I have built the
threaded version of bind (9.2.2 btw).  It does not always stop everything,
but it sure seems to often enough.  It seems as if one thread handles the
zone transfer and if nobody asks for any information from the given zone
we will be ok, but once a thread tries to handle a request from that zone,
that thread gets stuck.

Does anyone have a solution?  Is there any way to make the zone transfers
happen "offline"?  I don't need them to be absolutely up to date.  I _do_
need to be able to satisfy other DNS queries.

(I thought of limiting the transfer times, but the granularity is too large.
I would need to limit it to only a few seconds and the unit is 1 minute.)

-- 
Gary Algier, WB2FWZ          gaa at ulticom.com             +1 856 787 2758
Ulticom Inc., 1020 Briggs Rd, Mt. Laurel, NJ 08054      Fax:+1 856 866 2033

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