NAMEpmieconf - generalized pmie rules and customizations
DESCRIPTION
The pmieconf file formats are used by the pmieconf(1) tool as a way to
generalize pmie(1) rule sets such that they can be easily configured for
different systems and different environments. There are two completely
different (although closely related) file formats discussed here, namely
``pmieconf-rules'' and ``pmieconf-pmie''.
The directory $PCP_VAR_DIR/config/pmieconf contains information about all
the default system pmie generalized rules and variables, including
default values for all variables. These files are in the pmieconf-rules
format. Although new pmieconf-rules files can be added, the files in
this directory should never be changed. Instead, use the pmieconf
utility to change variable values in the pmie configuration file.
The pmieconf-pmie format allows site specific customizations of the rules
contained in pmieconf-rules files and their associated variables. The
pmieconf-pmie format is generated by pmieconf and should not be edited by
hand. This generated file is in the pmie format, with some additional
information held at the head of the file - thus, the pmieconf-pmie format
is a superset of the pmie file format (extended to hold customizations to
the generalized rules, but also containing the actual performance rules
for pmie to evaluate) which can also be parsed by pmie (all extensions
are hidden within comments, and are thus meaningless to pmie itself).
The file $PCP_VAR_DIR/config/pmieconf/config.pmie contains local system
settings for pmieconf configurable variables. The variable settings in
this file replace the default values specified in
$PCP_VAR_DIR/config/pmieconf/*/*.
PMIECONF-PMIE SYNTAX
All rule customization lines in a valid pmieconf-pmie specification are
prefixed by ``//'' and are located at the head of the file - this allows
files containing a pmieconf-pmie specification to be successfully parsed
by pmie. A pmieconf-pmie must always have the first line in the form:
// pmieconf-pmie version pmieconf_path
The version specifies which version of the pmieconf-pmie syntax should be
used to parse this file. Currently the only supported version is 1. The
pmieconf_path specifies the path to the pmieconf-rules files which were
used, by pmieconf, to generate this file. This is discussed in the
pmieconf(1) man page (see the -r option).
The remainder of the specification consists of one line entries for each
of the modified variables. The syntax for each line is:
// rule_version rule_name rule_variable = value
The rule_version and rule_name are used to identify the rule with which
to associate the customization. These are followed by the rule_variable
name (i.e. the variable of rule rule_name which has been changed) for
which the new value is to be used.
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PMIECONF(4)PMIECONF(4)
A pmieconf-pmie specification must be terminated with the ``end''
keyword. This is used by pmieconf to distinguish where the
customizations ends, and the actual pmie rule component begins.
PMIECONF-PMIE EXAMPLE
The following example is a valid pmieconf-pmie format file, as generated
by pmieconf. In order to make changes by hand which are preserved by
pmieconf, see the comments contained in the generated file (below) as to
where such changes should be made.
// pmieconf-pmie 1 $PCP_VAR_DIR/config/pmieconf
// 1 memory.exhausted delta = "4 minutes"
// 1 memory.exhausted enabled = yes
// 1 memory.exhausted pcplog_action = yes
// end
//
// --- START GENERATED SECTION (do not change this section) ---
// generated by pmieconf on: [DATESTAMP]
//
// 1 memory.exhausted
delta = 4 minutes;
some_host (
( avg_sample (swap.pagesout @0..9 ) ) > 0 &&
30 %_sample swap.pagesout >= 5
) -> shell 10 min "$PCP_BINADM_DIR/pmpost Severe demand for real memory" \
" %vpgsout/s@%h";
// --- END GENERATED SECTION (changes below will be preserved) ---
To see how this all works, you can generate this file as follows:
# cat - | pmieconf-f /tmp/pmieconf.out \
-r $PCP_VAR_DIR/config/pmieconf/memory:$PCP_VAR_DIR/config/pmieconf/global
modify memory.exhausted delta "4 minutes"
modify memory.exhausted enabled yes
modify memory.exhausted pcplog_action yes
^D
#
Then verify that the generated file is a valid pmie configuration file
using:
# pmie -C /tmp/pmieconf.out
This parses the file, and then exits after reporting any syntax errors.
Now replace -C with -v (above), and watch pmie do its work!
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PMIECONF(4)PMIECONF(4)PMIECONF-RULES SYNTAX
A pmieconf-rules specification consists of a number of separate data
objects which together form a complete rule specification (note that a
specification may span multiple files and even multiple subdirectories).
Each object must have an identifier string and a data type, followed by
an (optional) list of attributes.
The generic specification of a pmieconf-rules object is thus:
type identifier [ attribute = value ]* ;
The set of valid types is: "rule" (rule definition), "string" (arbitrary,
double-quote enclosed string), "double", "integer", "unsigned", "percent"
(real number between 0 and 100), "hostlist" (space separated list of host
names), "instlist" (space separated list of metric instance names), and
the four pmie action types, namely "print", "shell", "alarm", and
"syslog".
Rule names use the ``.'' character to introduce the concept of a rule
group, e.g. "memory.exhausted" associates this rule with the "memory"
group. pmieconf can operate at either the level of rule groups or
individual rules. The group name "global" is reserved and may not be
used with any rule.
Usually when an object is created it is associated with the current rule.
However, if an object's name is preceded by the reserved group name
"global", then that object is visible to all rules.
The set of valid attributes is: "help" (descriptive text about this
object), "modify" (value is yes/no, flags whether pmieconf should allow
changes), "enabled" (value is yes/no, flags whether this is on or off -
only meaningful for rules and actions), "display" (yes/no - flags whether
pmieconf should show this object), "default" (value determined by type,
and is the default value for this object), and specific to objects of
rule type are the "version", "predicate", and "enumerate" attributes.
"version" and "predicate" are fairly self explanatory ("predicate" must
equate to a valid pmie rule when expanded), but "enumerate" requires
further discussion.
The "enumerate" clause is useful when you wish to generate multiple,
similar pmie rules from a single predicate. This is most useful for rule
definitions wishing to use the "some_inst" clause in the pmie language
across multiple hosts. For a rule to use these together, it must be
certain that the instance list is the same on all of the monitored hosts.
This is rarely true, so the "enumerate" attribute allows us to generate
multiple rules, expanded over variables of either type "instlist" or
"hostlist". These variables make up the value for the "enumerate"
attribute - which is a space-separated list of "instlist" or "hostlist"
variable names.
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Objects can be incorporated into other object definitions using the
$identifier$ syntax. See the example later for more insight into how
this is useful.
When pmieconf is generating the pmie configuration file, it looks at each
enabled rule with N enabled actions (where N > 0) and expands the string:
// "version" identifier
delta = $delta$;
"predicate" -> $threshold$ $action1$ & ... & $actionN$ ;
The delta, threshold, and action variables are defined globally (using
the "global" keyword) for all rules, but can, of course, be changed at
the level of an individual rule or rule group.
PMIECONF-RULES EXAMPLE
The following is an example of a single pmieconf-rules specification,
showing a number of different aspects of the language discussed above.
The example defines a rule ("memory.exhausted") and a string ("rule").
rule memory.exhausted
default = "$rule$"
predicate =
"some_host (
( avg_sample (swap.pagesout $hosts$ @0..9 ) ) > 0 &&
$pct$ %_sample swap.pagesout $hosts$ @0..9 >= $threshold$
)"
enabled = yes
version = 1
help =
"The system is swapping modified pages out of main memory to the
swap partitions, and has been doing this on at least pct of the
last 10 evaluations of this rule.
There appears to be insufficient main memory to meet the resident
demands of the current workload.";
string rule
default = "Severe demand for real memory"
modify = no
display = no;
Note that for the above rule to be complete, "threshold" and "pct" would
also need to be defined - for the full expression of this rule, refer to
$PCP_VAR_DIR/config/pmieconf/memory/exhausted.
FILES
$PCP_VAR_DIR/config/pmieconf/*/*
generalized system resource monitoring rules
$PCP_VAR_DIR/config/pmieconf/config.pmie
default super-user settings for system resource monitoring
rules
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$HOME/.pcp/pmie/config.pmie
default user settings for system resource monitoring rules
SEE ALSOpmie(1) and pmieconf(1).
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