memory leak or other problem

[David]

Andrew Armstrong wrote:
> I have a strange problem with my bind servers where the process runs 
> great until the memory usage gets very high. I am running CentOS 4.5 and 
> the latest version of Bind for that distribution bind-9.2.4-24. On one 
> of my servers there is not enough RAM in the system and about every 24 
> hours I have to restart the bind server. After I restart everything runs 
> great until I get to about 80% memory usage.
> 
> The same problem happens on my other 2 servers but they have 2 and 4 GB 
> of memory so this takes much longer. When the memory usage gets to 
> around 80% or more the dns server stops responding and I get a 
> notification from my nagios monitoring system.
> 
> Has anybody experienced this and if so what have you done to fix it? I 
> would like to just let these servers run and not have to worry about 
> them. I do realize I could just restart them every day but this is only 
> gonna work as long as they don't have to be restarted more then once a 
> day which for now is ok. I would like to find a more permanent solution 
> and more insight into what is causing this.
> 
> Thanks for any help. I searched google long and hard and have not found 
> anything that really helped.
> 

We are seeing something similar on one our SLES 10 boxes 
(bind-9.3.2-17.15).  The server in question is a secondary DNS.  Every 
40 minutes it gets reloaded to pick up any new zones.  named's memory 
foot print just keeps growing until it stops responding.

The primary DNS server, also SLES 10 - same bind version, does not show 
this problem.  Unlike the secondary DNS server, the primary DNS server 
only gets reloaded by hand, not automatically.

I've disabled the automatic reloads on the secondary dns to see if it is 
the cause of the problem.

I'll try lowering the TTL and setting the memory cache size as Florian 
Weimer suggested and see if it makes and improvement.

As a side note, I just noticed that with every DNS message getting 
logged (FORMERR, lame server resolving, SERVFAIL, etc) the memory 
footprint is growing.



David Filion