NAME¶

pmLoadDerivedConfig - load derived metric definitions from a file

C SYNOPSIS¶

#include <pcp/pmapi.h> int pmLoadDerivedConfig(char * fname); cc ... -lpcp

DESCRIPTION¶

Each line of the file fname is either a comment line (with a ``#'' in the first position of the line) or the declaration of a derived performance metric, specified as:

*

the name of the derived metric, using the same ``dot notation'' syntax that is used for PCP performance metrics, see PCPIntro(1) and pmns(5).

*

an equals sign (``='')

*

a valid expression for a derived metric, as described in pmRegisterDerived(3).

White space is ignored in the lines. For each line containing a derived metric definition, pmRegisterDerived(3) is called to register the new derived metric. The result from pmLoadDerivedConfig will be the number of derived metrics loaded from fname else a value less than zero in the case of an error.

EXAMPLE¶

# sample derived metric definitions
bad_in_pkts = network.interface.in.errors + network.interface.in.drops
# note the following would need to be on a single line ...
disk.dev.read_pct = 100 * delta(disk.dev.read) /
            (delta(disk.dev.read) + delta(disk.dev.write))

SEE ALSO¶

PCPIntro(1), PMAPI(3) and pmRegisterDerived(3).