If the application wants to force using a local Performance Metrics
Name Space (PMNS) instead of a distributed PMNS then it
must load the PMNS using
pmLoadNameSpace
or
pmLoadASCIINameSpace(3).
If the application is to use a distributed PMNS, then it should NOT
make a call to load the PMNS explicitly.
The
filename
argument designates the PMNS of interest.
For applications not requiring a tailored PMNS,
the special value
PM_NS_DEFAULT
may be
used for
filename,
to force the default local PMNS to be loaded.
The default local PMNS is found in the file
$PCP_VAR_DIR/pmns/root
unless the environment variable
PMNS_DEFAULT
is set, in which case the value is assumed to be the pathname
to the file containing the default local PMNS.
Externally a PMNS may be stored in either an ASCII format or a binary format.
The utility
pmnscomp(1)
is used to create the binary format from the ASCII format described in
pmns(4).
If the binary format is used, no checking is performed for aliasing
in which multiple names in the PMNS are associated with a single Performance
Metrics Identifier (PMID).
If the ASCII format is to be used, duplicate PMIDs are not allowed,
although
pmLoadASCIINameSpace(3)
provides an alternative interface with user-defined control
over the processing of duplicate PMIDs in an ASCII format PMNS.
pmLoadNameSpace
attempts to load the PMNS by trying the following combinations in order,
1.
Binary format from the file filename.bin
2.
Binary format from the file filename
3.
ASCII format from the file filename
pmLoadNameSpace
returns zero on success.
FILES
$PCP_VAR_DIR/pmns/root
the default local PMNS, when the environment variable
PMNS_DEFAULT
is unset
PCP ENVIRONMENT
Environment variables with the prefix
PCP_
are used to parameterize the file and directory names
used by PCP.
On each installation, the file
/etc/pcp.conf
contains the local values for these variables.
The
$PCP_CONF
variable may be used to specify an alternative
configuration file,
as described in
pcp.conf(4).
Values for these variables may be obtained programatically
using the
pmGetConfig(3)
function.