[smokeping-users] Smokeping installer

[G.W. Haywood]

Hi there,

On Sat, 4 Feb 2012, Kris De Rocker wrote:

> I'm looking for someone who wants to set up a smokeping application on a
> system (running centos 6) and that could give me a little howto he've
> done it (so i can do it by myself on other systems).  I've tried some
> how-to's on the internet, but none seems to work for centos 6.

There is plenty of documentation for Smokeping and it's better quality
than a lot of packages I can think of.  Forget Howtos, in general they
suck big-time.  Read the documentation which comes with Smokeping, and
follow the instructions.  One thing that often gets missed is what you
might call the 'bigger picture'.  That is take a step back and look at
what the system is made of.  Here's the bigger picture, in necessarily
rather broad brush-strokes.

Leaving aside slaving for the moment, you basically have three things:

(1) A smokeping daemon, which simply pings some other machines and
saves the resulting data in some RRD files (so you need the RRD tools
on the master machine).  Once this daemon has been installed it must
be started, then it just gets on with it.  It can log information to
files for debugging your installation if you like.  I like logs, they
help a great deal especially if (er, sorry, when) things don't work.
The daemon calls on a number of other 'helpers' so you need them to be
installed in the master (and probably slaves) and smokeping needs to
be avble to find them and use them.  That's all documented.  There are
a couple of little niggles with some of the helpers (instructions from
Smokeping sometimes, rarely, won't match a version of a helper that you
have installed) but you don't need to worry about that at this stage.

(2) A Web server, which runs some scripts to create graph images and
the like from the data in the RRD files.  Like the smokeping daemon,
the scripts are written in Perl, so as well as Apache you need Perl.
Apache needs to be configured correctly -- so that it can read the
data that it needs to read, find and execute the Perl scripts that it
needs to execute, and receive and respond to requests from clients.
Like the smokeping daemon, Apache runs as a daemon too, and it can log
a lot of useful information.

(3) A browser, which asks the Web server for the graphs.  The browser
is of course not necessarily running on the machine which serves the
browser's requests and there may of course be many browsers.

The Smokeping configuration files are logically structured, and a
little time spent reading about them should make it clear what it
required.  You will be much better off doing the work yourself since
WHEN things go wrong you will then be much better placed to fix them.

Most of the problems that new users have with Smokeping seem to me to
be related to filesystem permissions, and the locations of the various
bits of the Smokeping system in the filesystem.  Package maintainers
for the various Linux distributions will use widely differing places
in the filesystems of the different distributions for parts of their
packages.  Startup scripts fall generally into two camps (which causes
enough confusion) but even then there is a variety of flavours.  The
people who write "how I did it" often take no account of such things.

I would recommend downloading the original Smokeping package from the
authors' Website an installing it from the latest tarball rather than
relying on things like .rpm packages for Centos, as you will then get
the most up-to-date version of Smokeping and you will be able to talk
on the mailing list with people who have installed exactly what you
have installed in exactly the way that you have installed it.  Leave
slave servers until you have the master working to your satisfaction.

If you're running SeLinux, try switching it off and have another go as
that can often stop things working if not configured correctly.

Fifty Euros wouldn't even pay for the advice I've just given you gratis. :)

--

73,
Ged.