PMNS(4)PMNS(4)NAMEpmns - 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, that may be com‐
piled using pmnscomp(1) to produce a binary PMNS. Note that pmn‐
scomp(1) is normally invoked from the $PCP_VAR_DIR/pmns/Rebuild script
if necessary when pmcd(1) is started.
Loading of a PMNS is done by calling pmLoadNameSpace(3) which silently
tolerates either the ASCII or binary formats. Alternatively, pmLoad‐
ASCIINameSpace(3) may be used to load just the ASCII format.
If the binary format is used, no checking is performed for aliasing in
which multiple names in the PMNS are associated with a single 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. The external ASCII format for a PMNS conforms to the syn‐
tax 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 func‐
tions 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.
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 must begin with an alphabetic character,
and be followed by zero or more characters drawn from the alphabetics,
the digits and the underscore ``_'') character. For alphabetic charac‐
ters 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, met‐
rics 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 cor‐
responding 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 │
├────────┼──────────────────────────────────────────────────┤
│ 1-31 │ PMDAs from the PCP base product and/or IRIX │
├────────┼──────────────────────────────────────────────────┤
│ 32-39 │ Oracle │
├────────┼──────────────────────────────────────────────────┤
│ 40-47 │ Sybase │
├────────┼──────────────────────────────────────────────────┤
│ 48-55 │ Informix │
├────────┼──────────────────────────────────────────────────┤
│ 56-58 │ SNMP Gateway PMDA │
├────────┼──────────────────────────────────────────────────┤
│ 59-63 │ Linux PMDAs │
├────────┼──────────────────────────────────────────────────┤
│ 64-69 │ ISV PMDAs │
├────────┼──────────────────────────────────────────────────┤
│ 70-128 │ more PMDAs from the PCP base product and/or IRIX │
├────────┼──────────────────────────────────────────────────┤
│129-510 │ End-user PMDAs and demo PMDAs │
├────────┼──────────────────────────────────────────────────┤
│ 511 │ RESERVED │
└────────┴──────────────────────────────────────────────────┘
EXAMPLE
#define IRIX 1
#define FOO 317
root {
network
cpu
dynamic FOO:*:*
}
#define NETWORK 26
network {
intrate IRIX:NETWORK:1
packetrate
}
network.packetrate {
in IRIX:NETWORK:35
out IRIX:NETWORK:36
}
#define CPU 10
cpu {
syscallrate IRIX:CPU:10
util
}
#define USER 20
#define KERNEL 21
#define IDLE 22
cpu.util {
user IRIX:CPU:USER
sys IRIX:CPU:KERNEL
idle IRIX:CPU:IDLE
}
SEE ALSOPCPIntro(1), pmcd(1), pmcpp(1), pmnscomp(1), PCPIntro(3), PMAPI(3),
pmErrStr(3), pmGetConfig(3), pmLoadASCIINameSpace(3), pmLoadNameS‐
pace(3), pcp.conf(4) and pcp.env(4).
Performance Co-Pilot SGI PMNS(4)
