Provided by: pcp_6.2.0-1.1build4_amd64 
NAME
PMNS - the performance metrics name space
SYNOPSIS
$PCP_VAR_DIR/pmns
DESCRIPTION
When using the Performance Metrics Programming Interface (PMAPI) of the Performance Co-Pilot (PCP),
performance metrics are identified by an external name in a hierarchic Performance Metrics Name Space
(PMNS), and an internal identifier, the Performance Metric Identifier (PMID).
A PMNS specifies the association between a metric's name and its PMID.
A PMNS is defined on one or more ASCII source files.
Loading of a PMNS is done by calling pmLoadNameSpace(3) or pmLoadASCIINameSpace(3).
As of Version 3.10.3 of PCP, by default duplicate names for the same PMID are allowed in the PMNS,
although pmLoadASCIINameSpace(3) provides an alternative interface with user-defined control over the
processing of duplicate names in the PMNS. The external format for a PMNS conforms to the syntax and
semantics described in the following sections.
There is one default PMNS in the files below $PCP_VAR_DIR/pmns, although users and application developers
are free to create and use alternate PMNS's. For an example of this, see the PCP Tutorial in
$PCP_DEMOS_DIR/Tutorial.
Although an application can call pmLoadNameSpace(3), normally this is only done directly for the -n
command line option where an explicit root PMNS file is specified. Since PCP version 2 uses a
distributed PMNS (see below), an application can extract PMNS information from a host's PMCD or an
archive. If the PMNS source is a version 1 archive (see PCPIntro(1)), however, then the local PMNS will
be loaded using the path specified by the environment variable PMNS_DEFAULT.
DISTRIBUTED PMNS
In PCP version 1, the PMNS functions in the API all operated on a PMNS loaded locally from a file. Since
PCP version 2, however, PMNS functions may get the PMNS information remotely from a PMCD or directly from
the meta data of an archive.
PROCESSING FRAMEWORK
The PMNS specification is initially passed through pmcpp(1). This means the following facilities may be
used in the specification
+ C-style comments
+ #include directives
+ #define directives and macro substitution
+ conditional processing via #ifdef ... #endif, etc.
When pmcpp(1) is executed, the ``standard'' include directories are the current directory and
$PCP_VAR_DIR/pmns.
The pre-processing with pmcpp(1) may be omitted in some cases where the PMNS is known to not contain any
C-style comments, preprocessor directives or macros. Refer to the descriptions of
pmLoadASCIINameSpace(3) and pmLoadNameSpace(3) for details.
SYNTAX
The general syntax for a non-leaf node in the PMNS is as follows
pathname {
name [pmid]
...
}
Where pathname is the full pathname from the root of the PMNS to this non-leaf node, with each component
in the pathname separated by a ``.''. The root node for the PMNS must have the special name ``root'',
but the common prefix ``root.'' must be omitted from all pathnames. Each component in the pathname is
drawn from the ASCII(7) character set, beginning with an alphabetic character, and followed by zero or
more characters drawn from the alphabetics, the digits and the underscore ``_'') character. For
alphabetic characters in a pathname component, upper and lower case are distinguished.
Non-leaf nodes in the PMNS may be defined in any order.
The descendent nodes are defined by the set of names, relative to the pathname of their parent non-leaf
node. For the descendent nodes, leaf nodes have a pmid specification, non-leaf nodes do not. The syntax
for the pmid specification has been chosen to help manage the allocation of PMIDs across disjoint and
autonomous domains of administration and implementation. Each pmid consists of 3 integer parts,
separated by colons, e.g. 14:27:11. This hierarchic numbering scheme is intended to mirror the
implementation hierarchy of performance metric domain, metrics cluster (data structure or operational
similarity) and individual metric. In practice, the two leading components are likely to be macros in
the PMNS specification source, and pmcpp(1) will convert the macros to integers. These macros for the
initial components of the pmid are likely to be defined either in a standard include file, e.g.
$PCP_VAR_DIR/pmns/stdpmid, or in the current source file.
To support dynamic metrics, where the existence of a metric is known to a PMDA, but not visible in the
PMNS, a variant syntax for the pmid is supported, namely a domain number followed by asterisks for the
other components of the pmid, e.g. 14:*:*. The corresponding metric name forms the root of a subtree of
dynamic metric names defined in the corresponding PMDA as identified by the domain number.
The current allocation of the high-order (PMD or domain) component of PMIDs is as follows.
┌─────────┬────────────────────────────────────────────┐
│ Range │ Allocation │
├─────────┼────────────────────────────────────────────┤
│ 0 │ reserved │
├─────────┼────────────────────────────────────────────┤
│ 1-384 │ production PMDAs from PCP packages │
├─────────┼────────────────────────────────────────────┤
│ 385-510 │ end-user PMDAs (allocate from high to low) │
├─────────┼────────────────────────────────────────────┤
│ 511 │ reserved for dynamic PMNS entries │
└─────────┴────────────────────────────────────────────┘
EXAMPLE
#define KERNEL 1
#define FOO 387
root {
network
cpu
dynamic FOO:*:*
}
#define NETWORK 26
network {
intrate KERNEL:NETWORK:1
packetrate
}
network.packetrate {
in KERNEL:NETWORK:35
out KERNEL:NETWORK:36
}
#define CPU 10
cpu {
syscallrate KERNEL:CPU:10
util
}
#define USER 20
#define SYSTEM 21
#define IDLE 22
cpu.util {
user KERNEL:CPU:USER
sys KERNEL:CPU:SYSTEM
idle KERNEL:CPU:IDLE
}
SEE ALSO
PCPIntro(1), pmcd(1), pmcpp(1), PCPIntro(3), PMAPI(3), pmErrStr(3), pmGetConfig(3),
pmLoadASCIINameSpace(3), pmLoadNameSpace(3), pcp.conf(5) and pcp.env(5).
Performance Co-Pilot PCP PMNS(5)