Backends

General Information

The NagVis code is separated into several layers. One of these layers is the "data layer". The data layer is used to handle requests for information from third party sources like the Nagios NDO. We call this layer "backend" in general. There are some components inside NagVis to manage these backends which act as the glue between the single backends and the other layers.

Default backend

At the moment there are two backends delivered with the NagVis core packages: the ndomy and the ndo2fs backend. Both backends are described in detail below.
The ndomy backend is the default backend since NagVis 1.0. It fetches Nagios information from the NDO MySQL database.

Backend types

ndo2db MySQL backend (ndomy)

The ndo2db MySQL backend, in short ndomy backend, is used to fetch Nagios information like status and configuration data via a MySQL database. The Nagios addon called ndoutils stores all information which are present in a running Nagios in an MySQL database. This database is being queried by the NagVis ndomy backend.

You can use the following parameters to configure a ndomy backend:

ValueDefaultDescription
dbhostlocalhostHostname of the NDO Database
dbport3306Port of the NDO Database
dbnamedb_nagiosName of the NDO Database
dbuserrootUsername for Database Access (only needs read permissions)
dbpassrootPassword for Database Access (only needs read permissions)
dbprefix nagios_ Prefix of the tables in NDO Database (like defined in ndo2db.cfg)
dbinstancename default Name of the Nagios instance in NDO Database (like defined in ndomod.cfg)
maxtimewithoutupdate180Maximum delay in seconds after last update in NDO. NagVis will report Nagios is not running if the delay is reached

There are also some general parameters. You can see them in main configuration format description.

ndo2fs backend

ValueDefaultDescription
path/usr/local/ndo2fs/varPath to the ndo2fs var directory. The files in this directory should be ndo2fs.pid, VOLATILE and PERSISTENT.
instancenamedefaultName of the backend instance.
maxtimewithoutupdate180Maximum delay in seconds after last update in NDO. NagVis will report Nagios is not running if the delay is reached

There are also some general parameters. You can see them in main configuration format description.

Other backend types

FIXME: Hint to other backends (Create own, 3rd party backends, ...).

Configuring backends

The backends are defined in the main configuration file. See main configuration format description on how to define backends.