Bind memory usage keeps increasing

CTRLBREAK · 06-14-2011, 03:42 PM

Hello there,

I'm running a recursive DNS server on Ubuntu Server 10.04 64bits and Bind 9.7.0-p1 and having issues with memory usage.

The named process memory usage keeps increasing from about 500Mb to 4Gig inside of a couple of weeks.

If I don't restart Bind in the mean time the swap fills and performance gets very bad.

Would greatly appreciate any input on that problem.

Thanks.

bathory · 06-14-2011, 04:24 PM

Hi,

It shouldn't happen, but anyway you can use max-cache-size to specify the maximum amount of memory used for cache.

Regards

CTRLBREAK · 06-14-2011, 05:02 PM

Thanks for the reply,

I will give it a try, that could be the case here... As soon as I issue the "service bind9 restart" command the memory usage goes back to just 500Mb.

CTRLBREAK · 06-17-2011, 08:05 AM

Hello,

I've tried adding the following setting in Bind: max-cache-size 2048M;

My server memory usage is still going up all the time. I can see that the named process is using over 3g of memory.
Here is top's output:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11158 bind 20 0 3864m 3.5g 1916 S 31 91.5 2350:39 named

Any idea why this is happening?

Thanks a lot.

sang_froid · 06-17-2011, 08:56 AM

Did you restart named service after making config changes ?

Quote:

Originally Posted by CTRLBREAK

Hello,

I've tried adding the following setting in Bind: max-cache-size 2048M;

My server memory usage is still going up all the time. I can see that the named process is using over 3g of memory.
Here is top's output:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11158 bind 20 0 3864m 3.5g 1916 S 31 91.5 2350:39 named

Any idea why this is happening?

Thanks a lot.

CTRLBREAK · 06-17-2011, 04:45 PM

Yes I did restart the bind9 service and it did free up most of my memory but afterward it keeps growing.

Thanks for the reply anyway.

bathory · 06-17-2011, 05:34 PM

Hi,

I guess this is the total amount of memory used by bind during its operation. Bind uses memory to load its code, shared libraries etc and to build its cache.
See the output of:

Code:

pmap `pidof named`

that is equal to the VIRT column of top command.
So I don't think you can make a secure conclusion from top output about the total cache size.

You can add a statistics channel and watch your cache behavior. To do so, add

Code:

statistics-channels {
inet 127.0.0.1 port 9999 allow { 127.0.0.1; };
};

and visit http:localhost:9999

Regards