Provided by: libpcp3-dev_5.0.3-1_amd64 
NAME
pmSeriesQuery, pmSeriesValues, pmSeriesLoad - fast, scalable time series querying
C SYNOPSIS
#include <pcp/pmwebapi.h>
int pmSeriesQuery(pmSeriesSettings *sp, sds *query, pmSeriesFlags flags, void *arg);
int pmSeriesValues(pmSeriesSettings *sp, pmSeriesTimeWindow *window, int count, sds *series, void *arg);
int pmSeriesLoad(pmSeriesSettings *sp, sds *query, pmSeriesFlags flags, void *arg);
cc ... -lpcp_web
DESCRIPTION
Searching for time series identifiers and values using the Performance Co-Pilot (PCP) fast, scalable time
series services is achieved using the pmseries(1) utility, and associated pmproxy(1) REST API service.
The implementation of these facilities is shared and available for other programs to use as well. The
functionality is provided through asynchronous APIs, which function in an event-driven fashion where
callbacks are invoked for each set of series identifiers or values structure being returned. These
callbacks must be registered using pmSeriesSetup(3) before any query API calls are made.
As a general pattern, these interfaces take an opaque (void * pointer) parameter, arg. This pointer will
be passed through unchanged and is typically used to access a data structure maintaining state within the
calling program.
Depending on the pmseries query string provided, pmSeriesQuery operates in one of two modes.
Firstly, if no time window specification is provided (square brackets), then the interface will return
only matching series identifiers and no values. These identifiers are returned via the on_match callback
registered using pmSeriesSetup.
The second mode is where a time window specification is used in the query string, or when the
pmSeriesValues interface is used. This mode provides values and time stamps for all matching time series
identifiers having data points within the provided time window. In this case, the results are returned
via the on_value callback registered using pmSeriesSetup.
Further metadata (metric names, labels, units, semantics, type, etc) about matched time series and their
values can be obtained using the interfaces described on the pmSeriesDescs(3) manual page.
Typically, loading of time series is handled automatically by the pmproxy daemon, which uses the
pmDiscoverSetup(3) series of interfaces to automatically detect and load logged time series from
pmlogger(1). However, it is also possible to manually load time series from a PCP archive using the
pmSeriesLoad interface. The provided query string must provide an archive or directory to load data from
using the source.path keyword.
DIAGNOSTICS
Where these functions return a status code, this is always zero on success. On failure a negative PMAPI
error code is returned.
SEE ALSO
pmproxy(1), pmlogger(1), pmSeriesSetup(3), pmSeriesDescs(3), pmDiscoverSetup(3), PMAPI(3) and PMWEBAPI(3).