From: Daniel Berger <djberg96@...>
Date: 2005-07-17T23:20:53+09:00
Subject: Re: Cheapest ping possible

Matthew Margolis wrote:
> I have a client/server application that I am currently developing that
> requires the server to ping all clients once every five minutes or so to
> verify that the clients are up and active.  The business server machine
> we have at our disposal is a pretty low end linux box and there is
> eventually going to be several thousand clients.  How would all you
> smart people out there reccomend I do the pinging?  It needs to be very
> easy on the server and as fast as it can be.  If the company has 2000 of
> their employees use the system then I have to ping 7 clients a second.
> Threading of some sort seems like a must as nonconcurrent pinging seems
> like it would take forever if there were lots of timeouts.
> The only requirements are that I am able to get a ping time for each
> client.  It doesn't really matter what sort of data I am sending around.
>
> I know about ruby ping
> (http://www.ruby-doc.org/stdlib/libdoc/ping/rdoc/index.html).  Has
> anyone used this library for a lot of concurrent pings?  Are there any
> better solutions out there for what I need?
>
>
> Thank you,
> Matthew Margolis

I use net-ping, available on the RAA.  I use that because, well, I
wrote it. :)

Yes, threads are probably the way to go:

require "net/ping"
include Net

threads = []
hosts.each{ |host_to_ping|
   threads << Thread.new(host_to_ping){ |host|
      ping_obj = PingTCP.new(host) # or UDP, or whatever you prefer
      unless ping_obj.ping?
         # Failed to ping 'host'
      end
   }
}

threads.each{ |t| t.join }

Regards,

Dan