Several Performance Co-Pilot (PCP) tools and utilities support the use of metric labels. This functionality applied a hierarchical set of labels to each instance of every metric, as described in pmLookupLabels(3).
The pmcd(1) and pmproxy(1) daemons are particularly important to the labels system, respectively providing the labels in real-time and then discovering recorded (archive) labels and indexing these for pmseries(1) queries using a redis-server(1).
The /etc/pcp/labels.conf file is a single point of configuration for behaviour affecting all labels exported by pmcd or through tools using PMAPI local context services. It uses the common “ini” file format and any variable it specifies that is not in an explicit square-bracket enclosed section is considered a [global] variable.
The available configuration variables are as follows :
When specified in the [global] section, controls the manner in which the local machine-id(5) is exported as a label. The default setting (none) exports a "machineid" context label with value reflecting the contents of the /etc/machine-id file, on any platforms that provide this file. The alternative (sha256) exports a "machineid_sha256" label, instead, and the value is the SHA256 (one-way) hash of the file.
pmcd(1), pmproxy(1), pmseries(1), redis-server(1), PMAPI(3), pmLookupLabels(3) and machine-id(5).