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NAME | SYNOPSIS | DESCRIPTION | DISTRIBUTED PMNS | PROCESSING FRAMEWORK | SYNTAX | EXAMPLE | SEE ALSO | COLOPHON |
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PMNS(5) File Formats Manual PMNS(5)
PMNS - the performance metrics name space
$PCP_VAR_DIR/pmns
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.
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.
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 preprocessing 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.
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 │
└─────────┴────────────────────────────────────────────┘
#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
}
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).
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to [email protected]. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2025-08-11.
(At that time, the date of the most recent commit that was found
in the repository was 2025-08-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
Performance Co-Pilot PCP PMNS(5)
Pages that refer to this page: chkhelp(1), collectl2pcp(1), dbpmda(1), genpmda(1),