NAME
YATG - Fast SNMP data poller daemon, with storage and graphing
VERSION
version 5.140510
DESCRIPTION
YATG is a daemon (background process) which at intervals wakes up and
polls network devices for SNMP data, and then stores or prints that
data. In this distribution are also included examples for presenting
simple CGI web pages with graphs.
YATG is flexible, efficient and powerful. It can poll a large number of
devices with thousands of ports in just a few seconds. The configuration
is very simple, and the defaults sane (it's designed for sysadmins,
after all).
You can use YATG both for historical logging, such as traffic counters
on ports, as well as short-term monitoring which might feed into, say,
Nagios. Wherever possible, data is translated to human-friendly formats
for storage, such as using Leaf Names instead of OIDs, translated values
("up", "down", etc) and device port names rather than SNMP Interface
Indexes.
How Does It Work?
At startup, "yatg_updater" loads its configuration from local files and
a database, performs some basic SNMP connections to build a cache about
device capabilities and so on, and then goes to sleep.
Periodically, as determined by the configuration, "yatg_updater" wakes
up and polls all devices, then stores results, again according to
instructions in the configuration.
If you have only the essential dependencies installed (see below) then
you can only output results to STDOUT. With other modules, you have more
options such as local or remote disk, or memcached based storage.
"yatg_updater" will re-load all its configuration if given a HUP signal.
If you run the daemon persistently (for example with "daemontools") then
a cron job once a day is a good way to refresh the configuration. There
is reference to this in one of the bundled example files.
What's in this distribution
"yatg_updater"
This is the main application, designed to be run persistently. It
does not accept any input and only produces output when in debugging
mode. It is a smart wrapper for the SNMP::Effective module.
YATG::Store family of modules
These are modules which take the SNMP poll results and store them to
either local Disk, a Memcached server, the disk on a remote
networked server, or Nagios via NSCA.
YATG::Retrieve family of modules
These are modules which read stored results back to you, for a given
time window. The data can be retrieved from local Disk, a Memcached
server, or the disk on a remote networked server.
"yatg_trim"
If using the Disk Store backend for results, eventually you'll want
to save space by deleting old data. This script understands the
backend file format and, given a duration, removes that amount of
historical data from the file.
RPC::Serialized handlers
If storing and/or retrieving on a remote networked server, it should
run an instance of RPC::Serialized, and these are the RPC Handlers
for that server (see that module's documentation for further
details).
CGI For the special case of viewing graphs of disk-based poll results
for switch port traffic counters, there is are two CGI scripts. One
is a wrapper which presents an HTML page embedded with PNG images
created from the other script.
Examples
The "examples/" folder includes a copy of each of the files you
should need for a complete deployment of YATG. Obviously some of
them contain dummy data.
Where to go from here
To begin with, you probably want to see how to configure "yatg_updater"
in YATG::Config.
Alongside that, there are examples of all the files you should need to
install, in the "examples/" folder of this distribution.
Each of the Store and Retrieve modules might have additional Perl module
dependencies (i.e. from CPAN) - see the relevant docs for more details.
LOGGING and TESTING
This module uses "Log::Dispatch::Syslog" for logging, and by default
will log timing data to your system's syslog service. More information
is provided in the YATG::Config documentation.
To run in debug mode, where timing data is output to standard out rather
than syslog, set the environment variable "YATG_DEBUG" to a true value.
To run the poller just once, set the "YATG_SINGLE_RUN" environment
variable to a true value. This is great for development. It makes
"yatg_updater" load its configuration, generate the device hints cache,
sleep and then run just one poll cycle before exiting.
To override the interval between polling runs, set the "YATG_INTERVAL"
environment variable to a number of seconds.
For example:
YATG_DEBUG=1 YATG_SINGLE_RUN=1 /usr/bin/yatg_updater /etc/yatg.yml
SEE ALSO
SNMP::Effective
This system uses SNMP::Effective at its core do the polling.
RPC::Serialized
Store polled data on another server using RPC::Serialized.
AUTHOR
Oliver Gorwits <oliver@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2014 by University of Oxford.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.