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NAME | SYNOPSIS | DESCRIPTION | Pass 0 | Pass 1 | Pass 2 | Pass 3 | FILES | PCP ENVIRONMENT | SEE ALSO | DIAGNOSTICS | COLOPHON |
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PMLOGCHECK(1) General Commands Manual PMLOGCHECK(1)
pmlogcheck - checks for invalid data in a PCP archive
pmlogcheck [-lwz] [-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).
Normally pmlogcheck operates on the default Performance Metrics Name
Space (pmns(5)), however if the -n option is specified an alternative
namespace is loaded from the file pmnsfile.
The command line options -S and -T can be used to specify a time
window over which metrics should be checked in Pass 3 (see below).
These options are common to many Performance Co-Pilot tools and are
fully described in PCPIntro(1).
The -l option prints the archive label, showing the log 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.
By default, pmlogcheck reports the time of day according to the local
timezone on the system where pmlogcheck is run. The -Z option
changes the timezone to timezone in the format of the environment
variable TZ as described in environ(7). The -z option changes the
timezone to the local timezone at the host that is the source of the
performance metrics, as specified in the label record of the archive
log.
The checking proceeds in a number of passes, each designed to
validate progressively more complex semantic relationships between
the information in a PCP archive.
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.
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.
Validates the integrity of the metadata file, usually archive.meta.
Validates the integrity of each of the log 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), pmval(1), pmLookupDesc(3),
pcp.conf(5), pcp.env(5) and pmns(5).
All are generated on standard error and are intended to be self-
explanatory.
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
2018-02-02. (At that time, the date of the most recent commit that
was found in the repository was 2018-02-02.) 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: pmdumplog(1), pmloglabel(1)
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