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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERATION | FILES | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
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PMLOGCHECK(1) General Commands Manual PMLOGCHECK(1)
pmlogcheck - checks for invalid data in a PCP archive
pmlogcheck [-lmvwz?] [-n pmnsfile] [-S start] [-T finish] [-Z
timezone] archive
pmlogcheck prints information about the nature of any invalid
data which it detects in the files of a PCP archive.
The archive has the base name archive and must have been
previously created using pmlogger(1).
The available command line options are:
-l, --label
Print the archive label, showing the archive format version,
the time and date for the start and (current) end of the
archive, and the host from which the performance metrics
values were collected.
-m, --metadataonly
Skip Pass 3 (see below) and only check the archive meta
data. This can run substantially faster in cases where the
volume data doesn't need to be checked, especially on
archives with compressed data volume(s).
-n pmnsfile, --namespace=pmnsfile
Load an alternative Performance Metrics Name Space (PMNS(5))
from the file pmnsfile.
-S starttime, --start=starttime
Specify the starttime of time window over which metrics
should be checked in Pass 3 (see below). Refer to
PCPIntro(1) for a complete description of the syntax for
starttime.
-T endtime, --finish=endtime
Specify the endtime of time window over which metrics should
be checked in Pass 3 (see below). Refer to PCPIntro(1) for
a complete description of the syntax for endtime.
-v, --verbose
Enable verbose mode.
-w, --nowrap
Suppress reporting of counter wraps.
-z, --hostzone
Use the local timezone of the host that is the source of the
performance metrics archive. The default is to use the
timezone of the local host.
-Z timezone, --timezone=timezone
Use timezone for the date and time. Timezone is in the
format of the environment variable TZ as described in
environ(7). The default is to use the timezone of the local
host.
-?, --help
Display usage message and exit.
The checking proceeds in a number of passes, each designed to
validate progressively more complex semantic relationships
between the information in a PCP archive.
Pass 0
Each physical file of the PCP archive is processed to ensure the
label records are valid and consistent, and that each file
contains an integral number of physical records with correct
header and trailer fields.
Any errors at this stage are usually fatal. The PCP archive is
probably damaged beyond repair, and no more passes of pmlogcheck
are attempted.
Pass 1
Validates the integrity of the temporal index, usually
archive.index.
As the temporal index is (strictly speaking) optional, errors at
this stage are handled by marking the index as bad and ignoring
it for the remainder of the pmlogcheck passes.
Permanent repair can be achieved by removing the temporal index
file and then making a copy of the PCP archive using
pmlogrewrite(1) or pmlogextract(1). This will create a new
temporal index for the copied archive as a side-effect.
Pass 2
Validates the integrity of the metadata file, usually
archive.meta.
Pass 3
Validates the integrity of each of the volumes of the PCP
archive, usually archive.0, archive.1, etc.
There is some basic integrity checks to ensure the encoding of
values for each metric remains consistent and the values are well
formed across all the observations in the archive.
Also the timestamps for the observations are expected to be
monotonically increasing as the archive is tranversed.
Additional attention is given to counter metrics (type from
pmLookupDesc(3) is PM_SEM_COUNTER) which are expected to have
monotonically increasing values. If the values are not monotonic
increasing this may suggest a counter wrap has happened or there
has been some interruption or reset to the underlying source of
the performance data that is no captured in the archive.
For each counter metric which has been detected as having wrapped
at some point in the archive, pmlogcheck produces output
describing the metric name (with instance identifiers where
appropriate), the internal storage type for the metric, the value
of the metric before the counter wrap (with its associated
timestamp), and the value of the metric after the wrap (also with
a timestamp).
The -w option may be used to suppress reporting of counter wraps.
pmlogcheck produces two different timestamp formats, depending on
the interval over which it is run. For an interval greater than
24 hours, the date is displayed in addition to the time at which
the counter wrap occurred. If the extent of the data being
checked is less than 24 hours, a more precise format is used
(time is displayed with millisecond precision, but without the
date).
$PCP_VAR_DIR/pmns/*
default PMNS specification files
$PCP_LOG_DIR/pmlogger/<hostname>
default directory for PCP archives containing performance
data collected from the host hostname.
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), pmdumplog(1), pmlogextract(1), pmlogger(1),
pmlogrewrite(1), pmlogsummary(1), pmLookupDesc(3), pcp.conf(5),
pcp.env(5) and PMNS(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@groups.io. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2023-12-22.
(At that time, the date of the most recent commit that was found
in the repository was 2023-12-16.) 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 PMLOGCHECK(1)
Pages that refer to this page: pmlogdump(1), pmloglabel(1), pmlogsize(1)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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