Multiple Named Daemon running at the same time

[Ryan Bernard]

Hi. Are there any issues when there are multiple named daemon running at the same time? I know that I wil not be able to stop named using "/sbin/init.d/named stop". I believe utilization will increase as well due to this?

Thanks alot

[TTr]

Technically you can but there are some problems. You would need to provide each named with a separate config file and a different port number. You could even have different sets of rc.config and start scripts.

A major issue would be the port number. You would have to point the DNS clients to a nonstandard port while connecting the the "second" named. The unix nslookup has this option but the actual hp-ux client configuration (resolv.conf) does not.

Also,
you can not use the "stop" script option as you mentioned because it relies on the /var/run/named.pid. Each named would write to the same pid filename and the named that started last, would overwrite the named.pid file.

You would not be able to use the sig_named utility either. You would have to send the appropriate kill signal to the PID of each named that you wanted to signal.

Other problems would be the debug files that named writes based on signals. Thefilenames would be the same for both named processes and they are listed at the bottom of the man page.

Now why would you want to do this? named supports multiple domains and networks in the same environment. I would imagine if you needed a test environment you would do this but it is too risky to mess up the production named while playing with the test named.

There may be other issues as well. Utilization might be ok based on the server that you have.

[VK2COT]

Hello,

Although possible, not very advisable or
needed.

Most of root DNS servers run BIND,
so there are many things to set before
one would jump to conclusion to use
multiple named processes:

http://www.root-servers.org/map/

If you suspect performance problems,
firstly check where the bottlenecks are (disk I/O, CPU, RAM, and so on).

a) How to run two named processes on a single host? One could be configured as a
delegated name server, another as a
resolving name server.

Since remote servers or resolvers query
the name servers on a port 53 (default DNS
port), you have to run your named servers on different IP addresses or ports.

If your host already has more than one network interface, that's no problem.

If it has only one network interface, the
operating system may support IP address
aliases. These allow you to attach more than
one IP address to a single network interface.
One named process can listen on each.

b) Check some tests for high-performance
BIND:

http://zaphods.net/~zaphodb/high-performance-bind9.html

In other words, verify if multi-threading
really works on your server, and if
max-cache-size might need to be
increased.

Regards,

VK2COT

[rick jones]

Are you trying to serve different sets of names out different interfaces?

As already pointed-out you will want to bind the different servers to different IP addresses.

As for load, while I suppose number of daemons may be a factor, load is really a function of the number of queries being processed per unit time, not how many server processes are serving them.

I believe there may be ways to configure a single instance of named to serve differnt sets of names out different interfaces. I've never tried myself, but suspect that some of the documentation on www.isc.org will describe it.