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
       pmLoadDerivedConfig(3), or per-context derived metrics using pmAddDerived(3) and pmAddDerivedDerived(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
              limit.

       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
              diagnostics, the value 0 disables them.

       PCP_DERIVED_DEBUG_SEMANTICS
              Debug  diagnostics  for  semantic  checks  during  the  binding  of  metrics in the derived metric
              expression 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),
              pmGetChildren(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),
       pmRegisterDerived(3), pmRegisterDerivedMetric(3) and PMNS(5).

Performance Co-Pilot                                                                         PMDERIVEDCONTROL(3)