PMSNAP(1)PMSNAP(1)NAMEpmsnap - generate performance summary snapshot images
SYNOPSIS
$PCP_BINADM_DIR/pmsnap [-NV] [-C dir] [-c configs] [-n names] [-o dir]
[-t type]
DESCRIPTIONpmsnap is a shell script that is normally run periodically from
crontab(1) to generate graphic images of pmchart(1) performance charts.
These images can be in any of the supported pmchart formats, including
png, bmp, and jpeg, and may be incorporated into the content offered by
the local Web server. The -V option enables verbose tracing of the
actions. By default pmsnap generates no output unless some error or
warning condition is encountered.
pmsnap generates images according to its control file, $PCP_PMSNAPCON‐
TROL_PATH (or dir/control if the -C option is specified), and uses ar‐
chive logs created by pmlogger(1) or PCP archive folios created by
pmafm(1) and pmlogger_check(1). Before attempting to configure pmsnap,
it is strongly recommended that pmlogger be configured according to the
descriptions in pmlogger_daily(1), pmlogger_check(1) and pmlogger(1).
Once pmlogger has been configured, it is necessary to configure pmsnap
as follows;
1. Edit the control file $PCP_PMSNAPCONTROL_PATH. The syntax of
this file is described in the comment at the head of the file
and an example is supplied for one and twelve hour "Summary"
performance charts for the local host. Suitable arguments for
pmchart are also described in the comment. The user should con‐
sult pmchart for further details. Note that when pmsnap is run,
it globally substitutes the string LOCALHOSTNAME with the name
of the local host in the control file.
2. Test the configuration by running
$PCP_BINADM_DIR/pmsnap.
Without any arguments pmsnap will process every non-comment line
in $PCP_PMSNAPCONTROL_PATH. The output images will be placed in
the files named in the first field of each line in the control
file, with the file format appended if necessary. If these file
names do not start with / or . then they are assumed relative
to dir, as specified with the -o option. The default dir is the
current directory. Note that if pmlogger has only been recently
started (within about the last 15 minutes), snap-shot images may
not be produced and no error messages will be issued - the rea‐
son is that pmchart can not use very short archives and hence,
neither can pmsnap. For debugging purposes the -V flag should
be used.
3. Add an appropriate entry for pmsnap in the root user's crontab.
An example is supplied in $PCP_VAR_DIR/config/pmlogger/crontab.
4. Incorporate the pmsnap images into the local WWW content. Usu‐
ally, WWW pages use images that are relative to a particular
document root, so it is often convenient to use the -o command
line option to specify a sub-directory of the local WWW content,
and then create a web page in this directory that shows the
snapshot images with text and other content appropriate to the
local environment.
COMMAND LINE OPTIONSpmsnap accepts the following command line options;
-C dir The control file is located in the directory dir rather than in
the default $PCP_PMSNAPCONTROL_PATH location.
-c config-pattern
Only process lines in the control file which match the config-
pattern regular expression in the Config column.
-n name-pattern
Only process lines in the control file which match the name-pat‐
tern regular expression (see egrep(1)) in the Name column.
-o dir The output images having file names which do not start with / or
. will be placed in a directory relative to dir, otherwise the
output directory is relative to the current directory (i.e. the
default value for dir is ./). Note that dir must be a writable
directory path and may be on an NFS or CIFS file system.
The -N option enables a ``show me'' mode, where the actions are echoed,
but not executed, in the style of ``make -n''. Using -N in conjunction
with -V maximizes the diagnostic capabilities for debugging.
When either -n or -c are used, pmsnap will only process lines in the
control file which match all the supplied patterns. If no patterns are
given, then all lines will be processed. These arguments allow multi‐
ple entries for pmsnap in crontab so that different performance summary
images can be generated at different times or with different frequen‐
cies.
A sample HTML page, suitable for the Summary snapshot may be found in
$PCP_VAR_DIR/config/pmsnap/Summary.html.
Although pmsnap attempts to flush stdio(3) output buffers in the rele‐
vant pmlogger processes before generating snap-shots images, this may
fail for assorted reasons and no error message will be given.
pmsnap should not be invoked immediately after pmlogger_daily has
rolled the logs because the new archive logs will be too short to
obtain meaningful results. Note however that pmsnap will not report
errors from pmchart about not being able to comply with the -A option
on very short archives. In these cases no error will be reported and
no output images will be produced.
FILES
$PCP_PMSNAPCONTROL_PATH
pmsnap control file
$PCP_VAR_DIR/config/pmsnap/Summary
summary view for pmchart
$PCP_VAR_DIR/config/pmsnap/Summary.html
sample HTML page for summary snapshot
$PCP_LOG_DIR/pmlogger/hostname/Latest
PCP archive folio for the host hostname, as generated by
pmlogger_check
$PCP_VAR_DIR/config/pmlogger/crontab
example crontab entry
SEE ALSOcron(1), crontab(1), egrep(1), pmchart(1), pmafm(1), pmlc(1), pmlog‐
ger(1), pmlogger_daily(1), X(1), and Xvfb(1).
Performance Co-Pilot PMSNAP(1)
