Maintained by: NLnet Labs

[Unbound-users] Unbound mysteriously crashes

Haw Loeung
Tue Dec 23 01:06:49 CET 2008

Hi All,

We're in the process of replacing all of our caching nameservers with 
Unbound. During testing, it seems that Unbound is crashing and I'm unsure 
why. I've recompiled it with debugging enabled (--enable-debug) and 
"verbosity" set to 4. This is what the last few lines shows:

[1229989936] unbound[9396:0] debug: cache memory msg=72831 
rrset=281352 infra=89090 val=50470                                                                   
[1229989936] unbound[9396:0] debug: svcd callbacks end
[1229989936] unbound[9396:0] debug: close of port 29714
[1229989936] unbound[9396:0] debug: close fd 55
[1229989936] unbound[9396:0] debug: answer cb
[1229989936] unbound[9396:0] debug: Incoming reply id = ced6
[1229989936] unbound[9396:0] debug: Incoming reply addr = ip4 port 53 (len 16)
[1229989936] unbound[9396:0] debug: lookup size is 171 entries
[1229989936] unbound[9396:0] debug: received udp reply.
[1229989936] unbound[9396:0] debug: udp message[366:0] 
[1229989936] unbound[9396:0] debug: udp message[366:256] 
[1229989936] unbound[9396:0] debug: outnet handle udp reply
[1229989936] unbound[9396:0] debug: measured roundtrip at 1188 msec
[1229989936] unbound[9396:0] fatal error: services/outside_network.c:1303: 
serviced_callbacks: assertion rem failed

Unbound has been compiled with "--disable-rpath --with-pthreads --without-
solaris-threads --with-libevent=/usr/local/src/libevent-1.4.9-stable --with-ssl --
disable-static --enable-debug" and our config looks like this:

        # verbosity number, 0 is least verbose. 1 is default.
        verbosity: 1                                         

        # enable cumulative statistics, without clearing them after printing.
        statistics-cumulative: yes                                           
        extended-statistics: yes                                             

        # number of threads to create. 1 disables threading.
        # Set num-threads equal to the number of CPU cores on the system. 
        # E.g. for 4 CPUs with 2 cores each, use 8.                       
        num-threads: 2                                                    
        # power of 2 close to num-threads                                 
        msg-cache-slabs: 2                                                
        rrset-cache-slabs: 2                                              
        infra-cache-slabs: 2                                              
        key-cache-slabs: 2                                                

        # specify the interfaces to answer queries from by ip-address.
        # include file with interfaces                                
        include: "/var/unbound/"                        

        outgoing-range: 4096 
        num-queries-per-thread: 4096

        # the amount of memory to use for the message cache.
        msg-cache-size: 1024m                               

        # the amount of memory to use for the RRset cache.
        # Use roughly twice as much rrset cache memory as you use msg cache 
        # memory                                                            
        rrset-cache-size: 2048m                                             

        # disable IPv6.
        do-ip6: no     

        # disable daemonize. We need this to be set to "no" so the runner
        # program takes care of things.                                  
        do-daemonize: no                                                 

        # control which clients are allowed to make (recursive) queries
        # to this server. Specify classless netblocks with /size and action.
        # Use "allow_snoop" to enable "dig +trace"                          
        access-control: allow_snoop                               
        access-control: allow_snoop                               

        # use log-file instead of syslog.
        logfile: "/var/log/unbound.log"  

        # file to read root hints from.
        # get one from ftp://FTP.INTERNIC.NET/domain/named.cache
        root-hints: "/var/unbound/named.cache"                  

        # allow internal private ranges.
        local-zone: "" nodefault
        local-zone: "" nodefault
        local-zone: "" nodefault

# Remote control config section.
        # Enable remote control with unbound-control.
        control-enable: yes

        # what interfaces are listened to for remote control.

# Forward zones.
        name: ""

        name: ""

Any ideas based on the information provided?

Any suggestions on what I should try?

What other information should I provide to help?

Thanks in advance.



Haw Loeung
Systems Administrator
TPG Internet

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