[Pdns-users] PipeBackend Large Query Number Issue

[Matthew Alexander @ The JD Project]

I am having difficulty resolving an issue with the Pipe backend when a 
large number of queries are being received. 

My backend produces a dynamic CNAME for a query, based on user IP and 
current server status.  This works fine when there are not a large 
number of queries, however when there are a lot the queries from PDNS 
seem to get muddled.

Example:

If I query www.example.com with User 1 and User 2, then I see:
Query: 'Q   www.example.com     IN   ANY   -1   (User1's IP)'
Query: 'Q   www.user1.com   IN   ANY   -1   (User1's IP)'
Query: 'Q   www.example.com     IN   ANY   -1   (User2's IP)'
Query: 'Q   www.user2.com   IN   ANY   -1   (User2's IP)'

However if I set User 1 to regularly query pdns (ie several times a 
second)  I see:

Query: 'Q   www.example.com     IN   ANY   -1   (User1's IP)'
Query: 'Q   www.user1.com   IN   ANY   -1   (User1's IP)'
Query: 'Q   www.user1.com   IN   SOA    -1   (User2's IP)'
Query: 'Q   user1.com.   IN   NS    -1   (User2's IP)'

Is this User2 making the assumption of which connection to use because 
of the recent calls from User2, and then further requesting SOA and NS, 
or is the query getting muddled in PDNS because of too many simultaneous 
queries.  I have set all TTLs to 0.

Thanks,

Matt