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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION FILE SYNTAX | EXAMPLES | FILES | ENVIRONMENT | PCP ENVIRONMENT | SEE ALSO | DIAGNOSTICS | COLOPHON |
PMLOGGER(1) General Commands Manual PMLOGGER(1)
pmlogger - create archive log for performance metrics
pmlogger [-c configfile] [-h host] [-H hostname] [-K spec] [-l
logfile] [-L] [-m note] [-n pmnsfile] [-o] [-p pid] [-P] [-r] [-s
endsize] [-t interval] [-T endtime] [-u] [-U username] [-v volsize]
[-V version] [-x fd] [-y] archive
pmlogger creates the archive logs of performance metric values that
may be ``played back'' by other Performance Co-Pilot (see
PCPIntro(1)) tools. These logs form the basis of the VCR paradigm
and retrospective performance analysis services common to the PCP
toolkit.
The mandatory argument archive is the base name for the physical
files that constitute an archive log.
The -V option specifies the version for the archive that is
generated. By default a version 2 archive is generated, and the only
value currently supported for version is 2.
Unless directed to another host by the -h option or when directly
using PMDAs via the -o option, pmlogger will contact the Performance
Metrics Collector Daemon (PMCD) on the local host and use that as the
source of the metric values to be logged.
To support the required flexibility and control over what is logged
and when, pmlogger maintains an independent two level logging state
for each instance of each performance metric. At the first
(mandatory) level, logging is allowed to be on (with an associated
interval between samples), or off or maybe. In the latter case, the
second (advisory) level logging is allowed to be on (with an
associated interval between samples), or off.
The mandatory level allows universal specification that some metrics
must be logged, or must not be logged. The default state for all
instances of all metrics when pmlogger starts is mandatory maybe and
advisory off.
Use pmlc(1) to interrogate and change the logging state once pmlogger
is running.
If a metric's state is mandatory (on or off) and a request is made to
change it to mandatory maybe, the new state is mandatory maybe and
advisory off. If a metric's state is already advisory (on or off)
and a request is made to change it to mandatory maybe, the current
state is retained.
It is not possible for pmlogger to log specific instances of a metric
and all instances of the same metric concurrently. If specific
instances are being logged and a request to log all instances is
made, then all instances of the metric will be logged according to
the new request, superseding any prior logging request for the
metric. A request to log all instances of a metric will supersede
any previous request to log all instances. A request to log specific
instances of a metric when all instances are already being logged is
refused. To do this one must turn off logging for all instances of
the metric first. In each case, the validity of the request is
checked first; for example a request to change a metric's logging
state to advisory on when it is currently mandatory off is never
permitted (it is necessary to change the state to mandatory maybe
first).
Optionally, each system running pmcd(1) may also be configured to run
a ``primary'' pmlogger instance. This pmlogger instance is launched
by $PCP_RC_DIR/pmlogger, and is affected by the files
$PCP_SYSCONF_DIR/pmlogger/control,
$PCP_SYSCONF_DIR/pmlogger/control.d (use chkconfig(8) or similar
platform-specific commands to activate or disable the primary
pmlogger instance), $PCP_SYSCONFIG_DIR/pmlogger (environment variable
settings for the primary pmlogger)
$PCP_SYSCONF_DIR/pmlogger/pmlogger.options (command line options
passed to the primary pmlogger) and
$PCP_VAR_DIR/config/pmlogger/config.default (the default initial
configuration file for the primary pmlogger).
The primary pmlogger instance is identified by the -P option. There
may be at most one ``primary'' pmlogger instance on each system. The
primary pmlogger instance (if any) must be running on the same host
as the pmcd(1) to which it connects (if any), so the -h and -P
options are mutually exclusive.
Logging of some metrics is possible even in the absence of a local
pmcd(1), using the "local context" mode of operation. This is
activated using the -o option, and causes pmlogger to make use of
local DSO PMDAs instead of communicating with pmcd(1). When
operating using a local context, the -K option may be used to control
the DSO PMDAs that should be made accessible. The spec argument
conforms to the syntax described in __pmSpecLocalPMDA(3). More than
one -K option may be used.
When launched as a non-primary instance, pmlogger will exit
immediately if the configuration file causes no metric logging to be
scheduled. The -L option overrides this behavior, and causes a non-
primary pmlogger instance to ``linger'', presumably pending some
future dynamic re-configuration and state change via pmlc(1).
pmlogger will also linger without the -L option being used if all the
metrics to be logged are logged as once only metrics. When the once
only metrics have been logged, a warning message will be generated
stating that the event queue is empty and no more events will be
scheduled.
By default all diagnostics and errors from pmlogger are written to
the file pmlogger.log in the directory where pmlogger is launched.
The -l option may be used to override the default behavior. If the
log file cannot be created or is not writable, output is written to
standard error instead.
If specified, the -s option instructs pmlogger to terminate after a
certain size in records, bytes or time units has been accumulated.
If endsize is an integer then endsize records will be written to the
log. If endsize is an integer suffixed by b or bytes then endsize
bytes of the archive data will be written out (note, however, that
archive log record boundaries will not be broken and so this limit
may be slightly surpassed). Other viable file size units include: K,
Kb, Kbyte, Kilobyte for kilobytes and M, Mb, Mbyte, Megabyte for
megabytes and G, Gb, Gbyte, Gigabyte for gigabytes. These units may
be optionally suffixed by an s and may be of mixed case.
Alternatively endsize may be an integer or a floating point number
suffixed using a time unit as described in PCPIntro(1) for the
interval argument (to the standard PCP -t command line option).
Some examples of different formats:
-s 100
-s 100bytes
-s 100K
-s 100Mb
-s 10Gbyte
-s 10mins
-s 1.5hours
The default is for pmlogger to run forever.
The -r option causes the size of the physical record(s) for each
group of metrics and the expected contribution of the group to the
size of the PCP archive for one full day of collection to be reported
in the log file. This information is reported the first time each
group is successfully written to the archive.
The -U option specifies the user account under which to run pmlogger.
The default is the current user account for interactive use. When
run as a daemon, the unprivileged "pcp" account is used in current
versions of PCP, but in older versions the superuser account ("root")
was used by default.
The log file is potentially a multi-volume data set, and the -v
option causes pmlogger to start a new volume after a certain size in
records, bytes, or time units has been accumulated for the current
volume. The format of this size specification is identical to that
of the -s option (see above). The default is for pmlogger to create
a single volume log. Additional volume switches can also be forced
asynchronously by either using pmlc(1) or sending pmlogger a SIGHUP
signal (see below). Note, if a scheduled volume switch is in
operation due to the -v option, then its counters will be reset after
an asynchronous switch.
Independent of any -v option, each volume of an archive is limited to
no more than 2^31 bytes, so pmlogger will automatically create a new
volume for the archive before this limit is reached.
Normally pmlogger operates on the distributed Performance Metrics
Name Space (PMNS), however if the -n option is specified an
alternative local PMNS is loaded from the file pmnsfile.
Under normal circumstances, pmlogger will run forever (except for a
-s option or a termination signal). The -T option may be used to
limit the execution time using the format of time as prescribed by
PCPIntro(1). The time is interpreted within the time zone of the
PMCD server, unless the -y option is given, within which case the
time zone at this logger host is used.
Some examples of different formats:
-T 10mins
-T '@ 11:30'
From this it can be seen that -T 10mins and -s 10mins perform
identical actions.
Alternatively, pmlogger runtime may be limited to the lifetime of
another process by using the -p or --PID option to nominate the PID
of the process of interest. In this case the pmlogger will exit when
the other process no longer exists.
When pmlogger receives a SIGHUP signal, the current volume of the log
is closed, and a new volume is opened. This mechanism (or the
alternative mechanism via pmlc(1)) may be used to manage the growth
of the log files - once a log volume is closed, that file may be
archived without ill-effect on the continued operation of pmlogger.
See also the -v option above.
Historically the buffers for the current log may be flushed to disk
using the flush command of pmlc(1), or by sending pmlogger a SIGUSR1
signal or by using the -u option. The current version of pmlogger
and the libpcp routines that underpin pmlogger unconditionally use
unbuffered writes and a single fwrite(3) for each logical record
written, and so ``flushing'' does not force any additional data to be
written to the file system. The -u option, the SIGUSR1 handling and
the pmlc(1) flush command are retained for backwards compatibility.
When launched with the -x option, pmlogger will accept asynchronous
control requests on the file descriptor fd. This option is only
expected to be used internally by PCP applications that support
``live record mode''.
The -m option allows the string note to be appended to the map file
for this instance of pmlogger in the $PCP_TMP_DIR/pmlogger directory.
This is currently used internally to document the file descriptor
(fd) when the -x option is used, or to indicate that this pmlogger
instance was started under the control of pmlogger_check(1).
The -H option allows the hostname written into the archive label to
be overridden. This mirrors the -H option of pmcd(1) , but allows it
to be specified on the pmlogger process. Without this option, the
value returned from the logged pmcd(1) is used.
The configuration file may be specified with the -c option. If it is
not, configuration specifications are read from standard input.
If configfile does not exist, then a search is made in the directory
$PCP_VAR_DIR/config/pmlogger for a file of the same name, and if
found that file is used, e.g. if config.mumble does not exist in the
current directory and the file
$PCP_VAR_DIR/config/pmlogger/config.mumble does exist, then -c
config.mumble and -c $PCP_VAR_DIR/config/pmlogger/config.mumble are
equivalent.
The syntax for the configuration file is as follows.
1. Words are separated by white space (space, tab or newline).
2. The symbol ``#'' (hash) introduces a comment, and all text up to
the next newline is ignored.
3. Keywords (shown in bold below) must appear literally (i.e. in
lower case).
4. Each specification begins with the optional keyword log,
followed by one of the states mandatory on, mandatory off,
mandatory maybe, advisory on or advisory off.
5. For the on states, a logging interval must follow using the
syntax ``once'', or ``default'', or ``every N timeunits'', or
simply ``N timeunits'' - N is an unsigned integer, and timeunits
is one of the keywords msec, millisecond, sec, second, min,
minute, hour or the plural form of one of the above.
Internal limitations require the interval to be smaller than
(approximately) 74 hours. An interval value of zero is a
synonym for once. An interval of default means to use the
default logging interval of 60 seconds; this default value may
be changed to interval with the -t command line option.
The interval argument follows the syntax described in
PCPIntro(1), and in the simplest form may be an unsigned integer
(the implied units in this case are seconds).
6. Following the state and possible interval specifications comes a
``{'', followed by a list of one or more metric specifications
and a closing ``}''. The list is white space (or comma)
separated. If there is only one metric specification in the
list, the braces are optional.
7. A metric specification consists of a metric name optionally
followed by a set of instance names. The metric name follows
the standard PCP naming conventions, see pmns(5), and if the
metric name is a non-leaf node in the PMNS (see pmns(5)), then
pmlogger will recursively descend the PMNS and apply the logging
specification to all descendent metric names that are leaf nodes
in the PMNS. The set of instance names is a ``['', followed by
a list of one or more space (or comma) separated names, numbers
or strings, and a closing ``]''. Elements in the list that are
numbers are assumed to be internal instance identifiers, other
elements are assumed to be external instance identifiers - see
pmGetInDom(3) for more information.
If no instances are given, then the logging specification is
applied to all instances of the associated metric.
8. There may be an arbitrary number of logging specifications.
9. Following all of the logging specifications, there may be an
optional access control section, introduced by the literal token
[access]. Thereafter come access control rules that allow or
disallow operations from particular hosts or groups of hosts.
The operations may be used to interrogate or control a running
pmlogger using pmlc(1) and fall into the following classes:
enquire interrogate the status of pmlogger and the
metrics it is logging
advisory Change advisory logging.
mandatory Change mandatory logging.
all All of the above.
Access control rules are of the form ``allow hostlist :
operationlist ;'' and ``disallow hostlist : operationlist ;''.
The hostlist follows the syntax and semantics for the access
control mechanisms used by PMCD and are fully documented in
pmcd(1). An operationslist is a comma separated list of the
operations advisory, mandatory, enquire and all.
A missing [access] section allows all access and is equivalent
to allow * : all;.
The configuration (either from standard input or configfile) is
initially scanned by pmcpp(1) with the options -rs and -I
$PCP_VAR_DIR/config/pmlogger. This extends the configuration file
syntax with include file processing (%include), a common location to
search for include files ($PCP_VAR_DIR/config/pmlogger), macro
definitions (%define), macro expansion (%name and %{name}) and
conditional inclusion of lines (%ifdef name ... %else ... %endif and
%ifndef name ... %else ... %endif).
For each PCP utility, there is a sample pmlogger configuration file
that could be used to create an archive log suitable for replaying
with that tool (i.e. includes all of the performance metrics used by
the tool). For a tool named foo this configuration file is located
in $PCP_VAR_DIR/config/pmlogger/config.foo.
The following is a simple default configuration file for a primary
pmlogger instance, and demonstrates most of the capabilities of the
configuration specification language.
log mandatory on once { hinv.ncpu hinv.ndisk }
log mandatory on every 10 minutes {
disk.all.write
disk.all.read
network.interface.in.packets [ "et0" ]
network.interface.out.packets [ "et0" ]
nfs.server.reqs [ "lookup" "getattr" "read" "write" ]
}
log advisory on every 30 minutes {
environ.temp
pmcd.pdu_in.total
pmcd.pdu_out.total
}
%include "macros.default"
%ifdef %disk_detail
log mandatory on %disk_detail_freq {
disk.dev
}
%endif
[access]
disallow * : all except enquire;
allow localhost : mandatory, advisory;
archive.meta
metadata (metric descriptions, instance domains, etc.) for
the archive log
archive.0 initial volume of metrics values (subsequent volumes have
suffixes 1, 2, ...)
archive.index
temporal index to support rapid random access to the other
files in the archive log
$PCP_TMP_DIR/pmlogger
pmlogger maintains the files in this directory as the map
between the process id of the pmlogger instance and the IPC
port that may be used to control each pmlogger instance (as
used by pmlc(1))
$PCP_VAR_DIR/config/pmlogger/config.default
default configuration file for the primary logger instance
launched from $PCP_RC_DIR/pmlogger
$PCP_VAR_DIR/config/pmlogger/config.*
assorted configuration files suitable for creating logs
that may be subsequently replayed with the PCP
visualization and monitoring tools
$PCP_LOG_DIR/pmlogger/hostname
Default directory for PCP archive files for performance
metric values collected from the host hostname.
$PCP_SYSCONFIG_DIR/pmlogger
additional environment variables that will be set when the
primary pmlogger instance executes. Only settings of the
form "PMLOGGER_VARIABLE=value" will be honoured.
./pmlogger.log
(or $PCP_LOG_DIR/pmlogger/hostname/pmlogger.log when
started automatically by either $PCP_RC_DIR/pmlogger or one
of the pmlogger(1) monitoring scripts such as
pmlogger_check(1))
all messages and diagnostics are directed here
Normally pmlogger creates a socket to receive control messages from
pmlc(1) on the first available TCP/IP port numbered 4330 or higher.
The environment variable PMLOGGER_PORT may be used to specify an
alternative starting port number.
If set to the value 1, the PMLOGGER_LOCAL environment variable will
cause pmlogger to run in a localhost-only mode of operation, where it
binds only to the loopback interface.
The PMLOGGER_MAXPENDING variable can be set to indicate the maximum
length to which the queue of pending pmlc connections may grow.
The default sampling interval used by pmlogger can be set using the
PMLOGGER_INTERVAL variable (if not set, 60 seconds will be used).
Both the command line and directives in the configuration file will
override this value. It is an integer in units of seconds.
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), pmcd(1), pmdumplog(1), pmlc(1), pmlogger_check(1),
__pmSpecLocalPMDA(3), pcp.conf(5), pcp.env(5), pmns(5) and
chkconfig(8).
The archive logs are sufficiently precious that pmlogger will not
truncate an existing physical file. A message of the form
__pmLogNewFile: "foo.index" already exists, not over-written
__pmLogCreate: File exists
indicates this situation has arisen. You must explicitly remove the
files and launch pmlogger again.
There may be at most one primary pmlogger instance per monitored
host; attempting to bend this rule produces the error:
pmlogger: there is already a primary pmlogger running
Various other messages relating to the creation and/or deletion of
files in $PCP_TMP_DIR/pmlogger suggest a permission problem on this
directory, or some feral files have appeared therein.
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 PMLOGGER(1)
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