NAME

       pmGetDerivedControl, pmSetDerivedControl  - get and set controls for derived metrics

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmGetDerivedControl(int what, int *valuep);
       int pmSetDerivedControl(int what, int value);

       cc ... -lpcp

DESCRIPTION

       These  routines  may be used to influence the behaviour of the derived metric services that are activated
       for global derived metrics using pmRegisterDerived(3), pmRegisterDerivedMetric(3)  and  pmLoadDerivedCon‐
       fig(3), or per-context derived metrics using pmAddDerived(3) and pmAddDerivedMetric(3).

       The  what argument selects a control, the value argument provides a value for pmSetDerivedControl and the
       valuep argument is used to return the value for pmGetDerivedControl.

       The what argument has one of the following values:

       PCP_DERIVED_GLOBAL_LIMIT
              The maximum number of global derived metrics that may be defined.  The value -1 indicates no  lim‐
              it.

       PCP_DERIVED_CONTEXT_LIMIT
              The  maximum number of per-context derived metrics that may be defined.  The value -1 indicates no
              limit.

       PCP_DERIVED_DEBUG_SYNTAX
              Debug diagnostics during parsing of derived metric expression.  The value 1 enables  the  diagnos‐
              tics, the value 0 disables them.

       PCP_DERIVED_DEBUG_SEMANTICS
              Debug  diagnostics for semantic checks during the binding of metrics in the derived metric expres‐
              sion to the available metrics in a new PMAPI context.  The value 1 enables  the  diagnostics,  the
              value 0 disables them.

       PCP_DERIVED_DEBUG_EVAL
              Debug  diagnostics  when  derived metrics are used in PMAPI operations like pmFetch(3), pmGetChil‐
              dren(3), pmGetChildrenStatus(3), pmLookupDesc(3), pmLookupName(3), pmNameAll(3),  pmNameID(3)  and
              pmTraversePMNS(3).

RETURN VALUES

       Both routines return 0 on success, else a value less than 0 that can be decoded using pmErrStr(3).

SEE ALSO

       PCPIntro(1),  pmAddDerived(3),  pmAddDerivedMetric(3), PMAPI(3), pmErrStr(3), pmLoadDerivedConfig(3), pm‐
       RegisterDerived(3), pmRegisterDerivedMetric(3) and PMNS(5).

Performance Co-Pilot                                                                         PMDERIVEDCONTROL(3)