Issues with NSCA
Ken Snider
ken.snider at datawire.net
Fri Jan 17 00:12:41 CET 2003
Greetings all,
I've witnessed a perplexing issue with NSCA, and was hoping someone my have
experienced the same, and could perhaps offer a solution to the issue.
We use NSCA to monitor about 350 passive services onto our network. NSCA is
processed through xinetd -reuse, and has Connections per second (cps) and
instances set to 200, and UNLIMITED, respectively.
In essence, xinetd will happily accept up to 200 connections per second.
We use a wrapper to massage plugin data and pipe to send_nsca, which in turn
sends these results to our nagios server. We have about 5 plugin results per
server, or about 70 servers total doing this, every two minutes.
What this means is, every two minutes, 70 connections are made to NSCA and
processed.
The *connections* themselves seem to work just fine.. xinetd spawns all the
required nsca daemons and they seem to communicate well.
The problem, however, is that over time, while nagios will first process all
these requests without issue, every two minutes, over time, the process
seems to take longer and longer, until nagios eventually begins tripping our
freshness threshold, which is set at a more-than-generous 500 seconds.
The box doesn't experience significant load, nor does it seem to be
network-related. It appears that, for whatever reason, these requests simply
don't make it into the external command pipe, or they are somehow lost in
the process.
I'm hoping someone more familiar with the issue than I can explain *what*
NSCA does, when launched from xinetd, and "likely" blocking on the pipe as
the requests go into the server.
I'd hope the solution isn't "less passive checks", or "staggered more",
because that suggests that Nagios won't be able to scale as we grow, and
we'll reach a point where our passive requests exceed nagios' capability.
--
Ken Snider
Senior Systems Administrator
Datawire Communication Networks Inc.
-------------------------------------------------------
This SF.NET email is sponsored by: Thawte.com
Understand how to protect your customers personal information by implementing
SSL on your Apache Web Server. Click here to get our FREE Thawte Apache
Guide: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0029en
More information about the Users
mailing list