NAME

       __pmEquivInDom - check if two instance domains are equivalent

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/libpcp.h>

       int __pmEquivInDom(pmInDom a, pmInDom b)

       cc ... -lpcp

CAVEAT

       This documentation is intended for internal Performance Co-Pilot (PCP) developer use.

       These interfaces are not part of the PCP APIs that are guaranteed to remain fixed across releases, and at
       some point in the future they may not work or may provide different semantics.

DESCRIPTION

       Within the Performance Co-Pilot (PCP) each instance domain is assigned a unique Instance Domain Identifi‐
       er  (pmInDom).   Internally  a pmInDom is constructed from 2 fields: the domain number (of the associated
       Performance Metrics Domain Agent, or PMDA) and the serial number (assigned by the PMDA).

       In some unusual circumstances different PMDAs may support independent Instance Domains that are  semanti‐
       cally  equivalent, e.g. per CPU or per process identifier.  __pmEquivInDom provides a mechanism to deter‐
       mine if Instance Domain a is equivalent to Instance Domain b.

       The ``equivalence'' of Instance Domains is defined by an external configuration file, identified  by  the
       environment  variable  $PCP_INDOM_CONFIG or $PCP_ETC_DIR/pcp/indom.config by default.  The format for the
       configuration file is defined in the CONFIGURATION FILE section below.

       If $PCP_INDOM_CONFIG is an empty string, no equivalence mapping is loaded.

CONFIGURATION FILE

       An Instance Domain equivalence mapping file conforms to the following syntax:
       1.  Lines beginning with optional white space, followed by ``#'' are considered comments.
       2.  Blank lines are ignored.
       3.  Each remaining line defines one `equivalence map'' with a list of white-space separated instance  do‐
           mains,  each consisting of a number (the domain number), a period ``.'' and a number (the serial num‐
           ber).  As a special case to ``match all serial numbers'', the serial number part can be ``*''.

       The format of a pmInDom demands that a domain number is in the range 0 to 511, and a numeric serial  num‐
       ber is in the range 0 to 4194303.

DIAGNOSTICS AND RETURN VALUES

       The  return  value  is 1 if the Instance Domains are equivalent, else 0 if they are not.  In rare cases a
       return value of -1 is used to indicate some problem (reported on standard error) in  opening  or  parsing
       the configuration file.

SEE ALSO

       pmLookupInDom(3) and PMAPI(3).

Performance Co-Pilot                                   PCP                                       PMEQUIVINDOM(3)