Resolv-replace problem

Ruby
1

After running through aproximately 512 ip to name resolutions, the
resolv-replace library seems to become very slow and starts blocking
threads. Any ideas?

Any good alternatives for doing ip address to name lookups on thousands
of
systems?

– Matt
It’s not what I know that counts.
It’s what I can remember in time to use.

2

On Tue, 2007-01-23 at 07:44 +0900, Matt L. wrote:

Any good alternatives for doing ip address to name lookups on thousands of
systems?

You could have a look at Ruby/Cares[http://cares.rubyforge.org/]. It’s a
wrapper for c-ares, a library that performs name-resolving
asynchronously.

Feedback welcome :slight_smile:

Best regards,
Andre

3

On Jan 22, 2007, at 14:44, Matt L. wrote:

After running through aproximately 512 ip to name resolutions, the
resolv-replace library seems to become very slow and starts
blocking threads. Any ideas?

Any good alternatives for doing ip address to name lookups on
thousands of systems?

I’ve experienced this problem and assumed it was due to resolv-
replace waiting for the destination name servers to time out, but
didn’t verify. Have you examined this possibility?

If you’ve got 1000 bogus host names, 100 threads and a 30 second
timeout per thread you’ll still wait at least 5 minutes for all of
them to fail to resolve.

–
Eric H. - [email protected] - http://blog.segment7.net

I LIT YOUR GEM ON FIRE!

4

On Tue, 23 Jan 2007, Eric H. wrote:

Have you examined this possibility?

If you’ve got 1000 bogus host names, 100 threads and a 30 second timeout per
thread you’ll still wait at least 5 minutes for all of them to fail to
resolve.

Shouldn’t have to wait for all of the lookups to fail. Every time EACH
lookup fails, the threads should continue. I have a limit in my program
of 50 threads. After about 512 lookups, the number of threads goes from
50 active to 6 or 7 active. Even when using the same address range over
and over.

– Matt
It’s not what I know that counts.
It’s what I can remember in time to use.