1PMNEWLOG(1) General Commands Manual PMNEWLOG(1)
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6 pmnewlog - stop and restart archive logging for PCP performance metrics
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9 $PCP_BINADM_DIR/pmnewlog [-a accessfile] [-C saveconfig] [-c config‐
10 file] [-N] [-n pmnsfile] [-P] [-p pid] [-s] [-V] [other pmlogger
11 options] archive
12
14 pmnewlog may be used to stop and restart a running instance of pmlog‐
15 ger(1). This is most useful for managing multiple sets of Performance
16 Co-Pilot (PCP) archive logs. These archive logs record the history of
17 performance metric values that may be ``played back'' by other PCP
18 tools, and they form the basis of the VCR paradigm and retrospective
19 performance analysis services common to the PCP toolkit.
20 In normal usage, pmnewlog would be executed by cron(1) in the wee hours
22 to terminate one PCP archive log and start another, i.e. to perform log
23 rotation.
24 Even more common, would be the execution of pmnewlog from the PCP ar‐
26 chive management script pmlogger_daily(1). In this case, direct end-
27 user execution of pmnewlog is most unlikely.
28 The mandatory argument archive is the base name for the physical files
30 that will constitute the new archive log.
31 The pmlogger instance to be stopped and restarted must be running on
33 the same system as pmnewlog and is either the primary logger (the
34 default) or the logger with pid as specified by the -p option.
35 If the -n option is specified, then pmnewlog will use the namespace in
37 the pmnsfile, rather than the default Performance Metrics Name Space
38 (PMNS).
39 If no -c option is specified, pmnewlog will use pmlc(1) to connect to
41 the running pmlogger(1) and so determine all those metrics and
42 instances that are subject to mandatory logging or advisory on logging,
43 and the associated logging frequencies. This information is used to
44 synthesize a new pmlogger(1) configuration file. If the -n option is
45 specified, it will also be used for these interactions with pmlc(1).
46 If the -c option is specified, pmlogger(1) will be restarted with con‐
48 figfile as the configuration file. Normally configfile would be the
49 same configuration file used to start pmlogger(1) in the first place,
50 however note that since pmlogger(1) is restarted, any changes to the
51 logging status made using pmlc(1) will be lost, unless these have also
52 been reflected in changes to configfile.
53 If configfile does not exist, then a search is made in the directory
55 $PCP_VAR_DIR/config/pmlogger for a file of the same name, and if found
56 that file is used, e.g. if config.mumble does not exist in the current
57 directory and the file $PCP_VAR_DIR/config/pmlogger/config.mumble does
58 exist, then -c config.mumble and -c $PCP_VAR_DIR/config/pmlogger/con‐
59 fig.mumble are equivalent.
60 Access controls specifications for the new pmlogger(1) instance may
62 optionally be provided via the -a option. The contents of accessfile
63 should start with the literal token [access] and conform to the syntax
64 of the access controls section as described for pmlogger(1).
65 The -C option may be used to save the configuration file that pmnewlog
67 passes to the newly launched pmlogger(1).
68 If the pmlogger(1) instance needs to be started under the control of
70 pmsocks(1) to connect to a pmcd through a firewall, the -s option may
71 be used.
72 The -V option enables verbose reporting of the activity. By default no
74 output is generated unless some error or warning condition is encoun‐
75 tered.
76 The -N option enables a ``show me'' mode, where the actions are echoed,
78 but not executed, in the style of ``make -n''. Using -N in conjunction
79 with -V maximizes the diagnostic capabilities for debugging.
80 The other pmlogger options are as described for pmlogger(1). Note that
82 pmnewlog does not support the following options of pmlogger(1).
83 -h host
85 pmnewlog determines the host to which the new pmlogger(1) should
86 connect based upon the current host connection for the old
87 pmlogger(1).
88 -s samples
90 The new pmlogger(1) is expected to be long running, and the -s
91 option of pmnewlog takes precedence.
92 -T runtime
94 The new pmlogger(1) is expected to be long running
95 -V version
97 The new pmlogger will always create the latest version PCP ar‐
98 chive format, and the -V option of pmnewlog takes precedence.
99 -x fd The launched pmlogger cannot be controlled by pmRecordCon‐
101 trol(3).
102
104 The following sh(1) script could be executed by root via cron(1) to
105 start a new set of archive logs for the primary logger each evening. A
106 more complete version of this script may be found in
107 $PCP_BINADM_DIR/pmlogger_daily, and is documented in the manual page
108 for pmlogger_daily(1).
109 #!/bin/sh
111 # start new logs for PCP primary logger on this host
112 # standard place for logs
114 LOGDIR=$PCP_LOG_DIR/pmlogger/`hostname`
115 # each new log is named yymmdd.hh.mm
117 LOGNAME=`date "+%Y%m%d.%H.%M"`
118 # do it
120 [ ! -d $LOGDIR ] && mkdir -p $LOGDIR
121 cd $LOGDIR
122 $PCP_BINADM_DIR/pmnewlog -l $LOGDIR/pmlogger.log $LOGDIR
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125 archive.meta
126 metadata (metric descriptions, instance domains, etc.) for
127 the archive log
128 archive.0 initial volume of metrics values (subsequent volumes have
129 suffixes 1, 2, ...)
130 archive.index
131 temporal index to support rapid random access to the other
132 files in the archive log
133 $PCP_BINADM_DIR/pmlogger_daily
134 sample script to rotate archives for a number of loggers
135 SaveLogs if this directory exists within the directory that the ar‐
136 chive files will be created by a new pmlogger(1) then the log
137 file (from pmlogger's -l argument) will be linked into the
138 SaveLogs directory with the name archive.log so it can be
139 inspected at a later time. Because the cron-driven PCP ar‐
140 chive management scripts run under the uid of the user
141 ``pcp'', SaveLogs typically needs to be owned by the user
142 ``pcp''.
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145 Environment variables with the prefix PCP_ are used to parameterize the
146 file and directory names used by PCP. On each installation, the file
147 /etc/pcp.conf contains the local values for these variables. The
148 $PCP_CONF variable may be used to specify an alternative configuration
149 file, as described in pcp.conf(5).
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152 PCPIntro(1), pmcd(1), pmdumplog(1), pmlc(1), pmlogger(1), pmlog‐
153 ger_daily(1), pmsocks(1), pcp.conf(5) and pcp.env(5).
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156 Due to the precious nature of the archive logs, pmnewlog is rather
157 paranoid in its checking and validation, and will try very hard to
158 ensure that an appropriately configured pmlogger(1) can be restarted,
159 before terminating the existing pmlogger(1).
160 As a consequence of this checking, pmnewlog tends to generate rather
162 verbose error and warning messages.
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165 If no configfile is specified, the method for synthesizing a configura‐
166 tion file using a pmlc(1) connection to the existing pmlogger(1) is, of
167 necessity, incomplete. In particular, for metrics with dynamic under‐
168 lying instance domains, it is not possible to identify a configuration
169 that logs all instances of a metric all of the time, so rather the syn‐
170 thesized configuration file requests the continued logging of the set
171 of instances that exist at the time pmlogger(1) is interrogated by
172 pmnewlog.
173 If this situation is a concern, a fixed configuration file should be
175 used, and passed to pmnewlog via the -c option.
176Performance Co-Pilot PCP PMNEWLOG(1)