1PMLOGGER(1) General Commands Manual PMLOGGER(1)
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6 pmlogger - create archive log for performance metrics
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9 pmlogger [-CNLoPruy?] [-c conffile] [-h host] [-H hostname] [-K spec]
10 [-l logfile] [-m note] [-n pmnsfile] [-p pid] [-s endsize] [-t inter‐
11 val] [-T endtime] [-U username] [-v volsize] [-V version] [-x fd] ar‐
12 chive
13
15 pmlogger creates the archive logs of performance metric values that may
16 be ``played back'' by other Performance Co-Pilot (see PCPIntro(1))
17 tools. These logs form the basis of the VCR paradigm and retrospective
18 performance analysis services common to the PCP toolkit.
19 The mandatory argument archive is the base name for the physical files
21 that constitute an archive log. The archive argument may contain strf‐
22 time(3) meta-characters, which will be substituted prior to creating
23 the archive log files. When pmlogger is run as a service (see pmlog‐
24 ger_daily(1)), the standard archive base name template is %Y%m%d.%H.%M.
25 The -V option specifies the version for the archive that is generated.
27 By default a version 2 archive is generated, and the only value cur‐
28 rently supported for version is 2.
29 Unless directed to another host by the -h option or when directly using
31 PMDAs via the -o option, pmlogger will contact the Performance Metrics
32 Collector Daemon (PMCD) on the local host and use that as the source of
33 the metric values to be logged.
34 To support the required flexibility and control over what is logged and
36 when, pmlogger maintains an independent two level logging state for
37 each instance of each performance metric. At the first (mandatory)
38 level, logging is allowed to be on (with an associated interval between
39 samples), or off or maybe. In the latter case, the second (advisory)
40 level logging is allowed to be on (with an associated interval between
41 samples), or off.
42 The mandatory level allows universal specification that some metrics
44 must be logged, or must not be logged. The default state for all
45 instances of all metrics when pmlogger starts is mandatory maybe and
46 advisory off.
47 Use pmlc(1) to interrogate and change the logging state once pmlogger
49 is running.
50 If a metric's state is mandatory (on or off) and a request is made to
52 change it to mandatory maybe, the new state is mandatory maybe and
53 advisory off. If a metric's state is already advisory (on or off) and
54 a request is made to change it to mandatory maybe, the current state is
55 retained.
56 It is not possible for pmlogger to log specific instances of a metric
58 and all instances of the same metric concurrently. If specific
59 instances are being logged and a request to log all instances is made,
60 then all instances of the metric will be logged according to the new
61 request, superseding any prior logging request for the metric. A
62 request to log all instances of a metric will supersede any previous
63 request to log all instances. A request to log specific instances of a
64 metric when all instances are already being logged is refused. To do
65 this one must turn off logging for all instances of the metric first.
66 In each case, the validity of the request is checked first; for example
67 a request to change a metric's logging state to advisory on when it is
68 currently mandatory off is never permitted (it is necessary to change
69 the state to mandatory maybe first).
70 Optionally, each system running pmcd(1) may also be configured to run a
72 ``primary'' pmlogger instance. This pmlogger instance is launched by
73 $PCP_RC_DIR/pmlogger, and is affected by the files
74 $PCP_SYSCONF_DIR/pmlogger/control, $PCP_SYSCONF_DIR/pmlogger/control.d
75 (use chkconfig(8), systemctl(1) or similar platform-specific commands
76 to activate or disable the primary pmlogger instance), $PCP_SYSCON‐
77 FIG_DIR/pmlogger (environment variable settings for the primary pmlog‐
78 ger) $PCP_SYSCONF_DIR/pmlogger/pmlogger.options (command line options
79 passed to the primary pmlogger) and $PCP_VAR_DIR/config/pmlogger/con‐
80 fig.default (the default initial configuration file for the primary
81 pmlogger).
82 The primary pmlogger instance is identified by the -P option. There
84 may be at most one ``primary'' pmlogger instance on each system. The
85 primary pmlogger instance (if any) must be running on the same host as
86 the pmcd(1) to which it connects (if any), so the -h and -P options are
87 mutually exclusive.
88 Logging of some metrics is possible even in the absence of a local
90 pmcd(1), using the "local context" mode of operation. This is acti‐
91 vated using the -o option, and causes pmlogger to make use of local DSO
92 PMDAs instead of communicating with pmcd(1). When operating using a
93 local context, the -K option may be used to control the DSO PMDAs that
94 should be made accessible. The spec argument conforms to the syntax
95 described in pmSpecLocalPMDA(3). More than one -K option may be used.
96 When launched as a non-primary instance, pmlogger will exit immediately
98 if the configuration file causes no metric logging to be scheduled.
99 The -L option overrides this behavior, and causes a non-primary pmlog‐
100 ger instance to ``linger'', presumably pending some future dynamic re-
101 configuration and state change via pmlc(1). pmlogger will also linger
102 without the -L option being used if all the metrics to be logged are
103 logged as once only metrics. When the once only metrics have been
104 logged, a warning message will be generated stating that the event
105 queue is empty and no more events will be scheduled.
106 By default all diagnostics and errors from pmlogger are written to the
108 file pmlogger.log in the directory where pmlogger is launched. The -l
109 option may be used to override the default behavior. If the log file
110 cannot be created or is not writable, output is written to standard
111 error instead. If the logfile for the -l option is "-" (i.e. -l-)
112 then log messages are written to the standard output stream. This can
113 be particularly useful when running pmlogger manually, rather than as a
114 service daemon.
115 The -N option directs pmlogger to notify a service manager, typically
117 systemd(1), when it has started and is about to begin writing PCP ar‐
118 chive logs. This option would only normally be used when pmlogger is
119 run as a daemon service under the control of a service manager. For
120 more details, see __pmServerNotifyServiceManagerReady(3) and sys‐
121 temd(1). On platforms that do not use a service manager that supports
122 notifications, the -N option is basically a no-op.
123 If specified, the -s option instructs pmlogger to terminate after a
125 certain size in records, bytes or time units has been accumulated. If
126 endsize is an integer then endsize records will be written to the log.
127 If endsize is an integer suffixed by b or bytes then endsize bytes of
128 the archive data will be written out (note, however, that archive log
129 record boundaries will not be broken and so this limit may be slightly
130 surpassed). Other viable file size units include: K, Kb, KiB, Kbyte,
131 Kilobyte for kilobytes and M, Mb, MiB, Mbyte, Megabyte for megabytes
132 and G, Gb, GiB, Gbyte, Gigabyte for gigabytes. These units may be
133 optionally suffixed by an s and may be of mixed case. Alternatively
134 endsize may be an integer or a floating point number suffixed using a
135 time unit as described in PCPIntro(1) for the interval argument (to the
136 standard PCP -t command line option).
137 Some examples of different formats:
138 -s 100
139 -s 100bytes
140 -s 100K
141 -s 100Mb
142 -s 10Gbyte
143 -s 10mins
144 -s 1.5hours
145 The default is for pmlogger to run forever.
146 The -r option causes the size of the physical record(s) for each group
148 of metrics and the expected contribution of the group to the size of
149 the PCP archive for one full day of collection to be reported in the
150 log file. This information is reported the first time each group is
151 successfully written to the archive.
152 The -U option specifies the user account under which to run pmlogger.
154 The default is the current user account for interactive use. When run
155 as a daemon, the unprivileged "pcp" account is used in current versions
156 of PCP, but in older versions the superuser account ("root") was used
157 by default.
158 The log file is potentially a multi-volume data set, and the -v option
160 causes pmlogger to start a new volume after a certain size in records,
161 bytes, or time units has been accumulated for the current volume. The
162 format of this size specification is identical to that of the -s option
163 (see above). The default is for pmlogger to create a single volume
164 log. Additional volume switches can also be forced asynchronously by
165 either using pmlc(1) or sending pmlogger a SIGHUP signal (see below).
166 Note, if a scheduled volume switch is in operation due to the -v
167 option, then its counters will be reset after an asynchronous switch.
168 Independent of any -v option, each volume of an archive is limited to
170 no more than 2^31 bytes, so pmlogger will automatically create a new
171 volume for the archive before this limit is reached.
172 Normally pmlogger operates on the distributed Performance Metrics Name
174 Space (PMNS), however if the -n option is specified an alternative
175 local PMNS is loaded from the file pmnsfile.
176 Under normal circumstances, pmlogger will run forever (except for a -s
178 option or a termination signal). The -T option may be used to limit
179 the execution time using the format of time as prescribed by PCPIn‐
180 tro(1). The time is interpreted within the time zone of the PMCD
181 server, unless the -y option is given, within which case the time zone
182 at this logger host is used.
183 Some examples of different formats:
184 -T 10mins
185 -T '@ 11:30'
186 From this it can be seen that -T 10mins and -s 10mins perform identical
187 actions.
188 Alternatively, pmlogger runtime may be limited to the lifetime of
190 another process by using the -p or --PID option to nominate the PID of
191 the process of interest. In this case the pmlogger will exit when the
192 other process no longer exists.
193 When pmlogger receives a SIGHUP signal, the current volume of the log
195 is closed, and a new volume is opened. This mechanism (or the alterna‐
196 tive mechanism via pmlc(1)) may be used to manage the growth of the log
197 files - once a log volume is closed, that file may be archived without
198 ill-effect on the continued operation of pmlogger. See also the -v
199 option above.
200 When pmlogger receives a SIGUSR2 signal, the current archive log is
202 closed, and a new archive is opened. For this to succeed, the original
203 archive argument must include strftime(3) meta characters (e.g.
204 %Y%m%d.%H.%M), otherwise pmlogger will exit because the archive files
205 will already exit and pmlogger will not over-write existing archive
206 files.
207 Historically the buffers for the current log may be flushed to disk
209 using the flush command of pmlc(1), or by using the -u option. The
210 current version of pmlogger and the libpcp routines that underpin
211 pmlogger unconditionally use unbuffered writes and a single fwrite(3)
212 for each logical record written, and so ``flushing'' does not force any
213 additional data to be written to the file system. The -u option and
214 the pmlc(1) flush command are retained for backwards compatibility.
215 When launched with the -x option, pmlogger will accept asynchronous
217 control requests on the file descriptor fd. This option is only
218 expected to be used internally by PCP applications that support ``live
219 record mode''.
220 The -m option allows the string note to be appended to the map file for
222 this instance of pmlogger in the $PCP_TMP_DIR/pmlogger directory. This
223 is currently used internally to document the file descriptor (fd) when
224 the -x option is used, or to indicate that this pmlogger instance was
225 started under the control of pmlogger_check(1), (-m pmlogger_check) or
226 was re-exec'd (see execvp(3)) due to a SIGUSR2 signal being recieved as
227 described above (-m reexec).
228 The -H option allows the hostname written into the archive label to be
230 overridden. This mirrors the -H option of pmcd(1) , but allows it to
231 be specified on the pmlogger process. Without this option, the value
232 returned from the logged pmcd(1) is used.
233 The -C option will cause the configuration file to be parsed and pmlog‐
235 ger will then exit without creating an output archive, so when -C is
236 specified, the archive command line argument is not required. Any
237 errors in the configuration file are reported.
238
240 The configuration file may be specified with the -c option. If it is
241 not, configuration specifications are read from standard input.
242 If conffile does not exist, then a search is made in the directory
244 $PCP_VAR_DIR/config/pmlogger for a file of the same name, and if found
245 that file is used, e.g. if config.mumble does not exist in the current
246 directory and the file $PCP_VAR_DIR/config/pmlogger/config.mumble does
247 exist, then -c config.mumble and -c $PCP_VAR_DIR/config/pmlogger/con‐
248 fig.mumble are equivalent.
249 The syntax for the configuration file is as follows.
251 1. Words are separated by white space (space, tab or newline).
253 2. The symbol ``#'' (hash) introduces a comment, and all text up to
255 the next newline is ignored.
256 3. Keywords (shown in bold below) must appear literally (i.e. in
258 lower case).
259 4. Each specification begins with the optional keyword log, followed
261 by one of the states mandatory on, mandatory off, mandatory maybe,
262 advisory on or advisory off.
263 5. For the on states, a logging interval must follow using the syntax
265 ``once'', or ``default'', or ``every N timeunits'', or simply ``N
266 timeunits'' - N is an unsigned integer, and timeunits is one of
267 the keywords msec, millisecond, sec, second, min, minute, hour or
268 the plural form of one of the above.
269 Internal limitations require the interval to be smaller than
270 (approximately) 74 hours. An interval value of zero is a synonym
271 for once. An interval of default means to use the default logging
272 interval of 60 seconds; this default value may be changed to
273 interval with the -t command line option.
274 The interval argument follows the syntax described in PCPIntro(1),
276 and in the simplest form may be an unsigned integer (the implied
277 units in this case are seconds).
278 6. Following the state and possible interval specifications comes a
280 ``{'', followed by a list of one or more metric specifications and
281 a closing ``}''. The list is white space (or comma) separated.
282 If there is only one metric specification in the list, the braces
283 are optional.
284 7. A metric specification consists of a metric name optionally fol‐
286 lowed by a set of instance names. The metric name follows the
287 standard PCP naming conventions, see PMNS(5), and if the metric
288 name is a non-leaf node in the PMNS (see PMNS(5)), then pmlogger
289 will recursively descend the PMNS and apply the logging specifica‐
290 tion to all descendent metric names that are leaf nodes in the
291 PMNS. The set of instance names is a ``['', followed by a list of
292 one or more space (or comma) separated names, numbers or strings,
293 and a closing ``]''. Elements in the list that are numbers are
294 assumed to be internal instance identifiers, other elements are
295 assumed to be external instance identifiers - see pmGetInDom(3)
296 for more information.
297 If no instances are given, then the logging specification is
299 applied to all instances of the associated metric.
300 8. There may be an arbitrary number of logging specifications.
302 9. As of PCP version 4.0 and later, any metric name specification
304 that does not resolve to a leaf node in the PMNS is added to an
305 internal list of possible dynamic subtree roots. PMDAs can dynam‐
306 ically create new metrics below a dynamic root node in their PMNS,
307 and send a notification to clients that the PMNS has changed, see
308 pmdaExtSetFlags(3) and in particular the METRIC CHANGES section
309 for API details. This mechanism is currently supported by
310 pmdaopenmetrics(1) and pmdammv(1). When a fetch issued by pmlog‐
311 ger returns with the PMDA_EXT_NAMES_CHANGE flag set, pmlogger will
312 traverse the internal list of possible dynamic subtree nodes and
313 dynamically discover any new metrics. In effect, as of PCP ver‐
314 sion 4.0 and later, pmlogger can be configured to dynamically log
315 new metrics that appear in the future, after the configuration
316 file is initially parsed.
317 10. Following all of the logging specifications, there may be an
319 optional access control section, introduced by the literal token
320 [access]. Thereafter come access control rules that allow or dis‐
321 allow operations from particular hosts or groups of hosts.
322 The operations may be used to interrogate or control a running
324 pmlogger using pmlc(1) and fall into the following classes:
325 enquire interrogate the status of pmlogger and the metrics
327 it is logging
328 advisory Change advisory logging.
329 mandatory Change mandatory logging.
330 all All of the above.
331 Access control rules are of the form ``allow hostlist : opera‐
333 tionlist ;'' and ``disallow hostlist : operationlist ;''.
334 The hostlist follows the syntax and semantics for the access con‐
336 trol mechanisms used by PMCD and are fully documented in pmcd(1).
337 An operationslist is a comma separated list of the operations
338 advisory, mandatory, enquire and all.
339 A missing [access] section allows all access and is equivalent to
341 allow * : all;.
342 The configuration (either from standard input or conffile) is initially
344 scanned by pmcpp(1) with the options -rs and -I $PCP_VAR_DIR/con‐
345 fig/pmlogger. This extends the configuration file syntax with include
346 file processing (%include), a common location to search for include
347 files ($PCP_VAR_DIR/config/pmlogger), macro definitions (%define),
348 macro expansion (%name and %{name}) and conditional inclusion of lines
349 (%ifdef name ... %else ... %endif and %ifndef name ... %else ...
350 %endif).
351
353 The available command line options are:
354 -c conffile, --config=conffile
356 Specify the conffile file to use.
357 -C, --check
359 Parse configuration and exit.
360 -h host, --host=host
362 Fetch performance metrics from pmcd(1) on host, rather than from
363 the default localhost.
364 -l logfile, --log=logfile
366 Write all diagnostics to logfile instead of the default pmlog‐
367 ger.log.
368 -L, --linger
370 Run even if not the primary logger instance and nothing to log.
371 -K spec, --spec-local=spec
373 When fetching metrics from a local context (see -o), the -K option
374 may be used to control the DSO PMDAs that should be made accessi‐
375 ble. The spec argument conforms to the syntax described in
376 pmSpecLocalPMDA(3). More than one -K option may be used.
377 -m note, --note=note
379 Append note to the port map file for this instance.
380 -o, --local-PMDA
382 Use a local context to collect metrics from DSO PMDAs on the local
383 host without PMCD. See also -K.
384 -n pmnsfile, --namespace=pmnsfile
386 Load an alternative Performance Metrics Name Space (PMNS(5)) from
387 the file pmnsfile.
388 -p PID, --PID=PID
390 Log specified metrics for the lifetime of the pid PID.
391 -P, --primary
393 Run as primary logger instance. See above for more detailed
394 description of this.
395 -r, --report
397 Report record sizes and archive growth rate.
398 -s endsize, --size=endsize
400 Terminate after log size exceeds endsize.
401 -t interval, --interval=interval
403 Specify the logging interval. The default value is 60 seconds.
404 -T endtime, --finish=endtime
406 Specify the endtime when to end logging.
407 -u Use unbuffered output. This is the default (so this option does
409 nothing).
410 -U username, --username=username
412 When in daemon mode, run as user username.
413 -v volsize, --volsize=volsize
415 Switch log volumes after reaching log volume size volsize.
416 -V version, --version=version
418 Specify log archive version. The default and the only accepted
419 value is 2.
420 -x fd
422 Allow asynchronous control requests on the file descriptor fd.
423 -y Use local timezone instead of the timezone from the pmcd(1) host.
425 -?, --help
427 Display usage message and exit.
428
430 For each PCP utility, there is a sample pmlogger configuration file
431 that could be used to create an archive log suitable for replaying with
432 that tool (i.e. includes all of the performance metrics used by the
433 tool). For a tool named foo this configuration file is located in
434 $PCP_VAR_DIR/config/pmlogger/config.foo.
435 The following is a simple default configuration file for a primary
437 pmlogger instance, and demonstrates most of the capabilities of the
438 configuration specification language.
439 log mandatory on once { hinv.ncpu hinv.ndisk }
441 log mandatory on every 10 minutes {
442 disk.all.write
443 disk.all.read
444 network.interface.in.packets [ "et0" ]
445 network.interface.out.packets [ "et0" ]
446 nfs.server.reqs [ "lookup" "getattr" "read" "write" ]
447 }
448 log advisory on every 30 minutes {
450 environ.temp
451 pmcd.pdu_in.total
452 pmcd.pdu_out.total
453 }
454 %include "macros.default"
456 %ifdef %disk_detail
458 log mandatory on %disk_detail_freq {
459 disk.dev
460 }
461 %endif
462 [access]
464 disallow * : all except enquire;
465 allow localhost : mandatory, advisory;
466
468 The archive logs are sufficiently precious that pmlogger will not trun‐
469 cate an existing physical file. A message of the form
470 ...: "foo.index" already exists, not over-written
471 ...: File exists
472 indicates this situation has arisen. You must explicitly remove the
473 files and launch pmlogger again.
474 There may be at most one primary pmlogger instance per monitored host;
476 attempting to bend this rule produces the error:
477 pmlogger: there is already a primary pmlogger running
478 Various other messages relating to the creation and/or deletion of
480 files in $PCP_TMP_DIR/pmlogger suggest a permission problem on this
481 directory, or some feral files have appeared therein.
482
484 archive.meta
485 metadata (metric descriptions, instance domains, etc.) for the ar‐
486 chive log
487 archive.0
489 initial volume of metrics values (subsequent volumes have suffixes
490 1, 2, ...)
491 archive.index
493 temporal index to support rapid random access to the other files
494 in the archive log
495 $PCP_TMP_DIR/pmlogger
497 pmlogger maintains the files in this directory as the map between
498 the process id of the pmlogger instance and the IPC port that may
499 be used to control each pmlogger instance (as used by pmlc(1))
500 $PCP_VAR_DIR/config/pmlogger/config.default
502 default configuration file for the primary logger instance
503 launched from $PCP_RC_DIR/pmlogger
504 $PCP_VAR_DIR/config/pmlogger/config.*
506 assorted configuration files suitable for creating logs that may
507 be subsequently replayed with the PCP visualization and monitoring
508 tools
509 $PCP_ARCHIVE_DIR/<hostname>
511 Default directory for PCP archive files for performance metric
512 values collected from the host <hostname>.
513 $PCP_SYSCONFIG_DIR/pmlogger
515 additional environment variables that will be set when the primary
516 pmlogger instance executes. Only settings of the form "PMLOG‐
517 GER_VARIABLE=value" will be honoured.
518 ./pmlogger.log
520 (or $PCP_ARCHIVE_DIR/<hostname>/pmlogger.log when started automat‐
521 ically by either $PCP_RC_DIR/pmlogger or one of the pmlogger(1)
522 monitoring scripts such as pmlogger_check(1))
523 all messages and diagnostics are directed here
524
526 Normally pmlogger creates a socket to receive control messages from
527 pmlc(1) on the first available TCP/IP port numbered 4330 or higher.
528 The environment variable PMLOGGER_PORT may be used to specify an alter‐
529 native starting port number.
530 If set to the value 1, the PMLOGGER_LOCAL environment variable will
532 cause pmlogger to run in a localhost-only mode of operation, where it
533 binds only to the loopback interface.
534 The PMLOGGER_MAXPENDING variable can be set to indicate the maximum
536 length to which the queue of pending pmlc connections may grow.
537 The default sampling interval used by pmlogger can be set using the
539 PMLOGGER_INTERVAL variable (if not set, 60 seconds will be used). Both
540 the command line and directives in the configuration file will override
541 this value. It is an integer in units of seconds.
542 On platforms using systemd(1), and when the -N option is given, the
544 NOTIFY_SOCKET environment variable would normally be set by the service
545 manager prior to launching pmlogger.
546
548 Environment variables with the prefix PCP_ are used to parameterize the
549 file and directory names used by PCP. On each installation, the file
550 /etc/pcp.conf contains the local values for these variables. The
551 $PCP_CONF variable may be used to specify an alternative configuration
552 file, as described in pcp.conf(5).
553
555 PCPIntro(1), pmcd(1), pmdumplog(1), pmlc(1), pmlogger_check(1), system‐
556 ctl(1), systemd(1), execvp(3), pmSpecLocalPMDA(3), strftime(3),
557 __pmServerNotifyServiceManagerReady(3), pcp.conf(5), pcp.env(5), pmlog‐
558 ger(5), PMNS(5) and chkconfig(8).
559Performance Co-Pilot PCP PMLOGGER(1)