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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION | INSTALLATION | EXAMPLES | FILES | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
PMDAPIPE(1) General Commands Manual PMDAPIPE(1)
pmdapipe - command output capture performance metrics domain agent
(PMDA)
$PCP_PMDAS_DIR/pipe/pmdapipe [-c configfile] [-d domain] [-l logfile]
[-m memory]
pmdapipe is a configurable command output monitoring Performance
Metrics Domain Agent (PMDA). It can be seen as analogous to a
restricted shell, where options can be passed to preset commands, and
each line of their output is converted into a performance event.
These events can be consumed by client tools like pmval(1).
The pipe PMDA exports both event-style metrics reflecting timestamped
event records for text-oriented command output, as well as the more
orthodox sample-style metrics such as event counts and throughput
size values.
The PMDA is configured via a configfile which contains one line for
each process from which output can be captured, as described in the
``CONFIGURATION'' section below.
A brief description of the pmdapipe command line options follows:
-c specifies an alternate configuration file for the PMDA. By
default, a file named $PCP_PMDAS_DIR/pipe/pipe.conf and any
files below the $PCP_SYSCONF_DIR/pipe.conf.d/ directory are
used.
-d It is absolutely crucial that the performance metrics domain
number specified here is unique and consistent. That is, domain
should be different for every PMDA on the one host, and the same
domain number should be used for the same PMDA on all hosts.
-l Location of the log file. By default, a log file named pipe.log
is written in the current directory of pmcd(1) when pmdapipe is
started, i.e. $PCP_LOG_DIR/pmcd. If the log file cannot be
created or is not writable, output is written to the standard
error instead.
-m Limit the physical memory used by the PMDA to buffer event
records to maxsize bytes. As log events arrive at the PMDA,
they must be buffered until individual client tools request the
next batch since their previous batch of events. The default
maximum is 2 megabytes.
The set of allowed pipe commands is configured by simple text
file(s). The format is a single line for each command followed by an
optional access control section.
Blank lines and comments are permitted (even encouraged) in the
configuration file. A comment begins with a ``#'' character and
finishes at the end of the line.
Each command configuration line is of the form:
instance username command options
Where,
instance is a string identifying the pipe command, also exported
as the metric instance identifier.
username is the name of the user account under which the command
should run (e.g. "root")
command is the path to the binary which will be run to generate
piped output
options is an optional space-separated list of parameters to
pass to the command
This options list may contain numeric parameters
prefixed by the dollar-sign, and these will be
substituted with user-supplied values at the time the
command is run (similar to shell parameter
substitution).
Parameters are passed as a single space-separated or comma-separated
string to the pipe.firehose metric, using the pmStore(3) interface.
The pmval command provides store access via its -x option. User-
supplied parameters are restricted to containing alphanumeric
characters.
The access control section of the file must start with a line of the
form:
[access]
Leading and trailing whitespace may appear around and within the
brackets and the case of the access keyword is ignored. No other
text may appear on the line except a trailing comment.
Following this line, the remainder of the configuration file should
contain lines that allow or disallow use of commands from particular
users or groups.
User names and group names will be verified using the local
/etc/passwd and /etc/groups files (or an alternative directory
service), using the getpwent(3) and getgrent(3) routines.
Access for users or groups are allowed or disallowed by specifying
statements of the form:
allow user username : instance
disallow user username : instance
allow group groupname : instance
disallow group groupname : instance
The username and groupname names will be verified using the local
/etc/passwd and /etc/groups files (or an alternative directory
service), using the getpwent(3) and getgrent(3) routines.
The wildcard ``*'' can be used to refer to all instance names.
If you want access to the names, help text and values for the pipe
performance metrics, do the following as root:
# cd $PCP_PMDAS_DIR/pipe
# ./Install
This is an interactive installation process which prompts for each
log file path to be monitored (or command to be run), a metric
instance name to identify it, and whether access should be restricted
(refer to the -x option to pmval(1) for further details).
If you want to undo the installation, do the following as root:
# cd $PCP_PMDAS_DIR/pipe
# ./Remove
pmdapipe is launched by pmcd and should never be executed directly.
The Install and Remove scripts notify pmcd when the agent is
installed or removed.
Following is a simple example of pmdapipe configuration and use of
the pipe metrics to run the btrace command, by user bob:
bob> cat $PCP_PMDAS_DIR/pipe/pipe.conf
# instance user command
rw_syscalls root perf script rw-by-file $1
bdev_trace root btrace -w $1 /dev/$2
[access]
allow user bob : *;
allow user jane : bdev_trace;
allow group perf : rw_syscalls;
bob> pmval -i bdev_trace -x '5 sda' pipe.firehose
8,2 5 1 0.000000000 25227 A WS 734332384 + 24 <- (253,2) 734330336
8,0 5 2 0.000000414 25227 A WS 735358432 + 24 <- (8,2) 734332384
8,0 5 3 0.000000756 25227 Q WS 735358432 + 24 [qemu-kvm]
[...5 seconds worth]
bob>
$PCP_PMCDCONF_PATH
command line options used to launch pmdapipe
$PCP_PMDAS_DIR/pipe/pipe.conf
default configuration file for the pipe metrics
$PCP_PMDAS_DIR/pipe/help
default help text file for the pipe metrics
$PCP_PMDAS_DIR/pipe/Install
installation script for the pmdapipe agent
$PCP_PMDAS_DIR/pipe/Remove
undo installation script for the pmdapipe agent
$PCP_LOG_DIR/pmcd/pipe.log
default log file for error messages and other information
from pmdapipe
$PCP_SYSCONF_DIR/pipe.conf.d
directory containing additional configuration files for the
pipe metrics
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(5).
PCPIntro(1), pmval(1), pmcd(1), getpwent(3), getgrent(3), pmStore(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
pcp@oss.sgi.com. This page was obtained from the project's upstream
Git repository ⟨git://git.pcp.io/pcp⟩ on 2017-07-05. 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 man-pages@man7.org
Performance Co-Pilot PCP PMDAPIPE(1)