[bind10-dev] unexpected response from bind10

[zhangcuiling]

hi,
    i found something strange with bind10. in certain situation, bind10 replies with SERVFAIL for a while.

preparation
--------------------
[root at devel sbin]# ./bind10 --version
bind10 20101129 (BIND 10 20110120)

[root at devel bin]# cat demo.example.com.txt 
$TTL 43200
@       IN      SOA     NS1.example.com.        root.example.com. (
                2009042700      ; serial
                3600    ; refresh
                900     ; retry
                604801  ; expire
                7200    ; minimum
                )
        IN      NS      NS1
        IN      NS      NS2
        IN      NS      NS3

$ORIGIN demo.example.com.
ns1     IN      A       10.10.1.1
ns2     IN      A       10.10.1.2
ns3     IN      A       10.10.1.3

[root at devel bin]# ./b10-loadzone -o demo.example.com demo.example.com.txt
Using SQLite3 database file /home/zcl/software/bind10-devel/20110120/var/bind10-devel/zone.sqlite3
Zone name is demo.example.com.
Loading file "demo.example.com.txt"
8 RR(s) loaded in 0.13 second(s) (100.00% of demo.example.com.txt)              
Done.

experiment
--------------------
[root at devel sbin]# ./bind10 -p 30001
[root at devel sbin]# dig @localhost -p 30001 demo.example.com soa

; <<>> DiG 9.7.2-P2 <<>> @localhost -p 30001 demo.example.com soa
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63538
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;demo.example.com.              IN      SOA

;; ANSWER SECTION:
demo.example.com.       43200   IN      SOA     NS1.example.com. root.example.com. 2009042700 3600 900 604801 7200

;; AUTHORITY SECTION:
demo.example.com.       43200   IN      NS      NS1.demo.example.com.
demo.example.com.       43200   IN      NS      NS2.demo.example.com.
demo.example.com.       43200   IN      NS      NS3.demo.example.com.

;; ADDITIONAL SECTION:
NS1.demo.example.com.   43200   IN      A       10.10.1.1
NS2.demo.example.com.   43200   IN      A       10.10.1.2
NS3.demo.example.com.   43200   IN      A       10.10.1.3

;; Query time: 1 msec
;; SERVER: ::1#30001(::1)
;; WHEN: Thu Feb 24 14:59:20 2011
;; MSG SIZE  rcvd: 181

[root at devel sbin]# dig @localhost -p 30001 nxdomain.demo.example.com a

; <<>> DiG 9.7.2-P2 <<>> @localhost -p 30001 nxdomain.demo.example.com a
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 38494
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;nxdomain.demo.example.com.     IN      A

;; Query time: 0 msec
;; SERVER: ::1#30001(::1)
;; WHEN: Thu Feb 24 14:59:32 2011
;; MSG SIZE  rcvd: 43

after a while ( about 30 seconds ):
; <<>> DiG 9.7.2-P2 <<>> @localhost -p 30001 nxdomain.demo.example.com a
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 12707
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;nxdomain.demo.example.com.     IN      A

;; AUTHORITY SECTION:
demo.example.com.       43200   IN      SOA     NS1.example.com. root.example.com. 2009042700 3600 900 604801 7200

;; Query time: 0 msec
;; SERVER: ::1#30001(::1)
;; WHEN: Thu Feb 24 15:00:01 2011
;; MSG SIZE  rcvd: 88

queries in the following sequence can get correct responses:
./bind10 -p 30001
dig @localhost -p 30001 nxdomain.demo.example.com a

./bind10 -p 30001
dig @localhost -p 30001 demo.example.com a
dig @localhost -p 30001 nxdomain.demo.example.com a