noble (3) pmStore.3.gz

NAME

       pmStore, pmStoreHighRes - modify values of performance metrics

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmStore(const pmResult *result);
       int pmStoreHighRes(const pmHighResResult *result);

       cc ... -lpcp

DESCRIPTION

       In  some  special  cases  it  may be helpful to modify the current values of performance metrics, e.g. to
       reset a counter to zero, or to modify a ``metric'' which is a control variable for some agent  collecting
       performance metrics.

       The  routines  pmStore  and  pmStoreHighRes  are lightweight inverses of pmFetch(3) and pmFetchHighRes(3)
       respectively.

       The caller must build the result data structure (of course, this could have been returned from an earlier
       pmFetch(3) or pmFetchHighRes(3) call).

       It  is an error to pass a result to pmStore or pmStoreHighRes in which the numval field within any of the
       pmValueSet structures has a value less than one.

       The current Performance Metrics Application Programming Interface (PMAPI) context must be one with a host
       as  the  source of metrics, and the current value of the nominated metrics will be changed, i.e.  pmStore
       and pmStoreHighRes cannot be used to make retrospective changes to information in either the archives, or
       in the recent past for real-time sources of metrics.

       The return code from pmStore and pmStoreHighRes is zero for success.

DIAGNOSTICS

       PM_ERR_GENERIC
              At least one of the modifications was rejected.  No other status is available from below the PMAPI
              (this is the lightweight part of the functionality!).  In cases where the outcome of storing  into
              individual  metrics  is  important,  the  caller  should  make  one  call  to  either  pmStore  or
              pmStoreHighRes for each metric.  On the other hand, a bulk modification  can  be  performed  in  a
              single call for situations in which the outcome is not critical.

       PM_ERR_NOTHOST
              The current PMAPI context is an archive rather than a host, or it is a host that is not set to the
              current  time,  i.e.  has  been  ``rewound''  to   the   recent   past   using   pmSetMode(3)   or
              pmSetModeHighRes(3).

       PM_ERR_TOOSMALL
              The number of metrics specified in result is less than one.

       PM_ERR_VALUE
              One or more of the pmValueSets in result has a numval field with a value less than one.

SEE ALSO

       PMAPI(3), pmFetch(3), pmFetchHighRes(3), pmSetModeHighRes(3) and pmSetMode(3).