request drops in BIND?

[KyoungSoo Park]

I believe BIND can handle thousands of requests per second(I think I saw 
someone claims that
BIND can handle more than ten thosands of requests per second). I 
believe so.

But the problem here is, "what level of bulk requests that BIND starts 
to not respond to queries either because of UDP
stack overflow or BIND's mistake?"
If BIND can achieve thousands of requests per second under tens of 
thousands of requests per second,
can we say it's doing well? No response ultimately leads to 
retransmission of queries, which wastes the Internet resources.
(Please take a look at [Jung01], [Danzig92] about DNS performance.)

Actually I tested sending 10000 requests/second with an equal interval. 
(1 request/100 us).
BIND could handle about 2000 requests/second, while my UDP PING answered 
all perfectly.
All the test I did is to do just one local domain name lookup.

Thanks,
KyoungSoo

P.S. I still believe BIND should increase the UDP buffer size for port 53.
       That will ease the situation a lot.

Paul Vixie wrote:

>>But here is an important issue. If 178 bulk requests lead to no
>>response from BIND sometimes, then can we say BIND is doing well?  I
>>think the speed of 178 requests is happening every now and then in a
>>reasonable sized community.  It becomes problematic to run an
>>application which does very sensitive jobs depending on BIND's
>>performance.
>>    
>>
>
>BIND8 and BIND9 are both used on root name servers, which handle thousands
>of requests per second (each), including mixtures of large and small ones,
>and including "packet trains" of more than 178 requests back-to-back.  if
>your system is dropping queries under that load, it's due to bad kernel
>design, or bad kernel tuning, or inadequate hardware resources.
>
>  
>