Provided by: pcp_6.3.0-1_amd64 
NAME
pmlogctl - manage and control Performance Co-Pilot archivers
SYNOPSIS
pmlogctl [-afmNV?] [-C check_args] [-c class] [-i ident] [-p policy] command [host ...]
DESCRIPTION
pmlogctl may be used to manage non-primary instances of the Performance Co-Pilot (PCP) archiver
pmlogger(1). This would be most relevant in a PCP archiver ``farm'' where many pmlogger(1) instances
would be creating archives of performance data collected from pmcd(1) on many remote hosts.
The primary pmlogger(1) instance is closely linked to the local pmcd(1) process and as a consequence
shares the same control infrastructure, namely systemd(1) or the PCP init(1) ``rc scripts''. This is why
the primary pmlogger(1) instance cannot be managed with pmlogctl.
For brevity in the description below, the term ``instance'' means a pmlogger(1) instance.
All instances managed by pmlogctl, pmlogger_check(1) and pmlogger_daily(1) abide by the following rules:
1. Each instance is fetching performance data from a single pmcd(1) (i.e. one host), but each pmcd(1) may
be providing performance data to zero, one or more pmlogger(1) processes running on one or more hosts.
2. On the local host, each pmlogger(1) instance must be specified once in a pmlogger_check(1) control
file and pmlogger(1) creates archives in a unique directory, named in the 4th parameter of the
associated control file entry (see the CONFIGURATION section of pmlogger_check(1)).
3. Each instance belongs to exactly one class, optionally named using a $class=... assignment in the
associated control file. The special default class is reserved for all instances that do not have an
associated $class=... assignment. For reporting purposes (refer to the summary command below), the
primary pmlogger(1) instance is automatically assigned to the special primary class.
Each pmlogctl execution manages one or more instances updating the associated control files and then
running pmlogger_check(1) to effect the desired change.
The host arguments are usually valid host names. For all commands except create and cond-create
(described below) the host arguments may also be egrep(1) regular expressions that match the whole of a
valid host name, so the pattern used is actually ^host$. For example foo.* (matches all host names
beginning with ``foo'') or .*foo (matches all host names ending with ``foo'') or .*[fF][oO][oO].*
(matches all host names containing ``foo'' in upper, lower or mixed case).
The combination of a class from the optional -c option (or default) and the host arguments to each
command identifies a target of set instances to which the command operation should be applied.
The -i option may be used with the create or cond-create commands to override the instance identity that
is specified in the ident section of the class policy file (see the CLASS POLICY FILE section below).
Since the identifier must be unique across all instances and all classes, it only makes sense to use this
option when there is a single host argument.
Given the tasks that pmlogctl is undertaking it usually must be run as ``root'', the exceptions being the
status command or when the -N option is specified.
COMMANDS
command is one of the following:
check
Check the status of all currently configured pmlogger instances and restart any that have failed. If
the -m flag is given on systemd(1) platforms, also migrate matching (and new) processes to the
pmlogger_farm service.
create
Create new instances in the class classname (default by default) for the host hosts. The name of the
class is used to identify a class policy file (see the CLASS POLICY FILE section below) which
provides a template for each new control file with %h replaced by host and %i replaced by the
instance's (unique) identifier from the ident section of the class policy file or ident from the -i
option.
The -p option may be used to identify a class policy file other than the one found in the standard
place, i.e. $PCP_SYSCONF_DIR/pmlogger/class.d/classname.
At least one host must be specified for the create command.
cond-create
Similar to create but the instance will only be created if one of the conditions in the create
section of associated class policy file(s) evaluates to true.
If a -c option is specified, then only the class classname will be considered, otherwise all classes
will be considered. In the latter case, if none of the conditions in any of the classes evaluates to
true, the the special pmfind class is used (this is the ``default'' class for the cond-create command
when all else fails).
If more than one class evaluates to true then a composite pmlogger(1) configuration file is created
and the instance is also assigned to the special pmfind class. The composite configuration file may
contain a mix of explicit configuration clauses and the more general conditional configuration
clauses as understood by the pmlogconf(1) tool.
start
Start the target set of instances.
If the target set intentionally contains more than one instance, then the -a option should be used
(this is designed to reduce the risk of accidentally starting a potentially large number of
pmlogger(1) processes).
If an instance in the target set is already started, no change is made (see the restart command to
force new instances to be launched).
stop
Stop the target set of instances.
If the target set intentionally contains more than one instance, then the -a option should be used
(this is designed to reduce the risk of accidentally stopping a potentially large number of
pmlogger(1) processes).
If an instance in the target set is already stopped, no change is made but a warning is issued.
restart
Stop and then start the target set of instances.
If the target set intentionally contains more than one instance, then the -a option should be used
(this is designed to reduce the risk of accidentally stopping and starting a potentially large number
of pmlogger(1) processes).
If an instance in the target set is already stopped, a warning is issued before the instance is
started.
status
Report the status of the target set of instances. If there is no -c option specified and no host
arguments, i.e. the target set is empty, then all instances will be reported.
destroy
Destroy the target set of instances. At the end of this operation the associated pmlogger(1)
processes will have been stopped and the relevant control file information removed.
If the target set intentionally contains more than one instance, then the -a option should be used
(this is designed to reduce the risk of accidentally terminating a potentially large number of
pmlogger(1) processes and removing their pmlogger_check(1) configurations).
The policy file linked to the class of an instance to be destroyed may contain a destroy section that
may influence if and how the destroy operation should be performed. This may require a -p option to
find the associated class policy file.
The class policy checking can be by-passed using the -f (force) command line option.
CLASS POLICY FILE
A class policy file contains a number of sections, each section begins with a line that simply starts
with the name of the section followed enclosed by ``['' and ``]''.
Lines beginning with a hash (#) are treated as comments and ignored. Blank or empty lines are also
ignored.
The typical location of the policy file for the class foo is $PCP_SYSCONF_DIR/pmlogger/class.d/foo.
[class]
The optional class name section names the class. If it is missing, the name of the policy file
(stripped of any directory prefix) is used as the name of the class.
[ident]
The ident section specifies the template to be used for the instance identifier to be given to each
member of the class. This identifier needs to be unique across all instances and all classes, and it
needs to be a valid file name in the local filesystem, so would normally contain the class name and
the macro %h, e.g. foo-%h. The macro is replaced by the host when each instance is created.
[control]
The control section consists of one or more lines of template text that will be used to create the
control file for each instance. This must at least include the pmlogger_check(1) control line to
specify how to start the associated pmlogger(1) process; this line contains fields separated by white
space as follows:
1. the hostname, usually the macro %h
2. n to indicate this is a non-primary instance
3. the ``socks'' flag, typically n
4. the directory in which the pmlogger(1) archives will be created; this needs to be unique and is
usually specified using the pmlogger_check(1) macro PCP_ARCHIVE_DIR as the start of the path,
followed by the instance identifier, usually the macro %i, e.g. PCP_ARCHIVE_DIR/%i
5. additional parameters to pmlogger(1) which probably include at least a -c option to provide a
configuration file that describes which metrics should be logged for instances of this class,
which may be the same for all instances in this class, or it may include the %i macro to use a
different configuration file for each instance. Note that if this configuration file does not
exist, it will be created using pmlogconf(1) the first time pmlogger_check(1) is run.
Before the control line there should be a line that defines the version of the control line that
follows, i.e.
$version=1.1
If this is missing, pmlogctl will assume the version is 1.1 and insert the line when the instance is
created.
pmlogctl will also add the class name during creation. e.g.
$class=foo
[create]
The create section defines the conditions that must be met before an instance will be created with
the cond-create command. The intent is to allow different decisions to be made when a new host
running pmcd(1) is discovered, e.g. by pmfind(1).
Each non-blank line in the create section is a condition of the form function(arg), where function is
one of the following:
exists
arg is the name of a performance metric and exits evaluates to true if that metric exists in the
Performance Metrics Name Space (PMNS) on the remote host
values
arg is the name of a performance metric in the remote PMNS and values evaluates to true if some
instance of that metric has a value on the remote host
condition
arg is a derived metric expression in the format supported by pmRegisterDerived(3), and condition
evaluates to true if the value of that expression on the remote host is greater than zero
hostname
arg is a regular expression in the style of egrep(1) and hostname evaluates to true if the remote
host name matches arg
[destroy]
The destroy section defines the policy to be applied when an instance is destroyed.
The intent is to allow different decisions to be made when discovery service, e.g. pmfind(1),
notices that a host associated with an instance is no longer present. But in the current version
this is not implemented and the destroy section syntax and semantics is not yet defined.
A sample class policy file is as follows:
# policy file for the foo class
[class]
foo
[ident]
foo-%h
[control]
$version=1.1
%h n n PCP_ARCHIVE_DIR/%i -c foo-metrics.config
[create]
# matches all hosts
hostname(.*)
[destroy]
# still to be defined
OPTIONS
The available command line options are:
-a, --all
Apply action to all matching instances. By default only one instance definition is expected and
acted upon.
-c class, --class=class
Set the name of the class for which pmlogger(1) instances belong to as class.
-C check_args, --checkargs=check_args
check_args are additional command line arguments for pmlogger_check(1) when it is called. This is
most useful for options like -V. Multiple -C options may be used and the various check_args options
will be accumulated and all passed to pmlogger_check(1).
-f, --force
Force action if possible.
-i ident, --ident=ident
Override instance identifier with ident. This option applies only for the commands create and
cond-create.
-N, --showme
Runs pmlogctl in a ``show me'' or ``dry run'' mode where the intent of the command is shown, but no
changes are made.
-m, --migrate
When used with the create or check commands on systemd(1) platforms, also migrate new or existing
non-primary pmlogger processes to the pmlogger_farm service. This is normally done automatically by
the pmlogger_farm_check service, which is timer driven (so there may be a few minutes delay before
automatic migration is initiated).
-p policy, --policy=policy
Use policy as the class policy file. Defaults to $PCP_SYSCONF_DIR/pmlogger/class.d/<class>.
-V, --verbose
Enable verbose mode. Using this option twice increases verbosity. Verbose output is written to
stderr.
-?, --help
Display usage message and exit.
PCP ENVIRONMENT
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).
SEE ALSO
egrep(1), init(1), PCPIntro(1), pmcd(1), pmlc(1), pmlogconf(1), pmlogger(1), pmlogger_check(1), pmlogger_daily(1), systemd(1), PMAPI(3), pmDerivedRegister(3) and pcp.conf(5).