Ubuntu Manpage: pmieconf - generalized pmie rules and customizations

NAME

       pmieconf - 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.

       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!

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.

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
       $HOME/.pcp/pmie/config.pmie
                 default user settings for system resource monitoring rules