The summary PMDA exports performance metrics derived from performance metrics made available by other PMDAs. It is described completely in the pmdasummary(1) reference page.

The summary PMDA consists of two processes:

All of the metrics exported by the summary PMDA have a singular instance and the values are “instantaneous”; the exported value is the correct value as of the last time the corresponding expression was evaluated by the pmie process.

The summary PMDA resides in the /usr/pcp/pmdas/summary directory and may be installed with a default configuration by following the steps described in the section “PMDA Installation”.

Alternatively, the summary PMDA may be customized to export your own derived performance metrics, by following the procedure described below:

The PCP tool pmchart produces stripchart displays of performance metrics. Refer to “The pmchart Tool” for an extensive description of the capabilities of pmchart.

Customization is centered on PCP views that may be created interactively and saved via the View Save option in the Views menu.

When pmchart is loading a view, the following directories are searched:

The X11 application resources for pmchart are in /usr/lib/X11/app- defaults/PmChart, and these may be edited to customize the appearance of the display; the default update interval and other attributes are described in the pmchart(1) reference page.

The PCP archive logger is presented in Chapter 7, “Archive Logging,” and documented in the pmlogger(1) reference page.

The following global files and directories influence the behavior of pmlogger:

chkconfig pmlogger on

The PCP inference engine is presented in Chapter 6, “Performance Metrics Inference Engine,” and documented in the pmie(1) reference page.

The following global files and directories influence the behavior of pmie:

The PCP snapshot production facility is presented in “Making Snapshot Images From Archive Logs” and documented in the cron.pmsnap(1) reference page.

The following global files and directories influence the behavior of cron.pmsnap:

The gadget specification language of pmgadgets supports the creation of arbitrary gadget layouts and bindings to hosts and performance metrics. See “The pmgadgets Command” and the pmgadgets(1) reference page.

The 3D scene specification language of pmview supports the creation of block layouts and bindings to hosts and performance metrics. See Chapter 5, “System Performance Visualization Tools,” and the pmview(1) reference page.

The PMNS specification is initially passed through cpp. This means the following facilities may be used in the specification:

When cpp is executed, the “standard” include directories are the current directory and /var/pcp/pmns, where some standard macros and default specifications may be found.

Every PMNS is tree structured. The paths to the leaf nodes are the performance metric names. The general syntax for a non-leaf node in PMNS is as follows:

pathname {
name	[pmid]
...
}

Here pathname is the full pathname from the root of the PMNS to this non-leaf node, with each component in the path separated by a period. The root node for the PMNS has the special name root, but the prefix string root. must be omitted from all other pathnames.

For example, refer to the PMNS shown in Figure 9-1. The correct pathname for the rightmost non-leaf node is cpu.util, not root.cpu.util.

Each component in the pathname must begin with an alphabetic character and be followed by zero or more alphanumeric characters or the underscore (_) character. For alphabetic characters in a component, uppercase and lowercase are significant.

Non-leaf nodes in the PMNS may be defined in any order desired. The descendent nodes are defined by the set of names, relative to the pathname of their parent non-leaf node. For descendent nodes, leaf nodes have a pmid specification, but non-leaf nodes do not.

Figure 9-1. Small Performance Metrics Name Space (PMNS)

The syntax for the pmid specification was chosen to help manage the allocation of Performance Metric IDs (PMIDs) across disjoint and autonomous domains of administration and implementation. Each pmid consists of three integers separated by colons, for example, 14:27:11. This is intended to mirror the implementation hierarchy of performance metrics. The first integer identifies the domain in which the performance metric lies. Within a domain, related metrics are often grouped into clusters. The second integer identifies the cluster, and the third integer, the metric within the cluster.

For complete documentation of the PMNS and associated utilities, see the pmns(4), pmnscomp(1), pmnsadd(1), pmnsdel(1), and pmnsmerge(1) reference pages.

The PMNS specification for Figure 9-1 is as follows:

/*
 * PMNS Specification for Figure 4-1
 */
#include <stdpmid>
root {
    network
    cpu
}
#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
}