[smokeping-users] nss_ldap smokeping problem - fping polling taking too long problem

[Chris Wilson]

Hi Larry,

On Mon, 24 Mar 2008, Larry Low wrote:

> I think I see the problem with fping taking so long.  It does not seem 
> to be multithreaded so a host not responding holds up the entire 
> process.
>
> Am I correct?  Anyone know of another solution.  I want to be able to 
> send 5 pings to 500 hosts with growth of about 3000 per poller.

fping does not need to be multithreaded, it's asynchronous instead, which 
is much more efficient.

The main limit on fping is that it has to have enough time (at the maximum 
ping rate) to send the specified number of pings to each host, and then 
wait for the answer to arrive from the last one, before its timeout 
expires.

To ping a lot of hosts, you may have to reduce the minimum time between 
pings (which may require hacking fping) and set the timeout longer than 
the highest RTT that you expect from any host, otherwise the final ping 
response from a slow host will be lost, and reported as lost to smokeping.

Cheers, Chris.
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