All values sent to *collectd* must have an associated type. The type
defines the acceptable range of values. Types are defined in a simple
text file database. *collectd* loads all of the databases specified by
`TypesDB` directives in its configuration file. When configuring a
custom types database, the default database needs to be specified
explicitly; it will not be loaded automatically if there are any
`TypesDB` directives in the configuration.
The *unixsock* plugin for *collectd* provides a socket-based interface
that other software can use to communicate with *collectd*. Notably,
this can be used to publish custom values, query existing values, and
flush caches.
The socket is created at `/run/collectd/socket`. The `/run/collectd`
directory is managed by systemd; it will be created automatically when
the service starts and cleaned up when it stops.