// Query handles the /api/query endpoint.
func (api *API) Query(w http.ResponseWriter, r *http.Request) {
setAccessControlHeaders(w)
w.Header().Set("Content-Type", "application/json")
params := httputil.GetQueryParams(r)
expr := params.Get("expr")
timestamp, err := parseTimestampOrNow(params.Get("timestamp"), api.Now())
if err != nil {
httpJSONError(w, fmt.Errorf("invalid query timestamp %s", err), http.StatusBadRequest)
return
}
query, err := api.QueryEngine.NewInstantQuery(expr, timestamp)
if err != nil {
httpJSONError(w, err, http.StatusOK)
return
}
res := query.Exec()
if res.Err != nil {
httpJSONError(w, res.Err, http.StatusOK)
return
}
log.Debugf("Instant query: %s\nQuery stats:\n%s\n", expr, query.Stats())
httputil.RespondJSON(w, res.Value)
}
// QueryRange handles the /api/query_range endpoint.
func (api *API) QueryRange(w http.ResponseWriter, r *http.Request) {
setAccessControlHeaders(w)
w.Header().Set("Content-Type", "application/json")
params := httputil.GetQueryParams(r)
expr := params.Get("expr")
duration, err := parseDuration(params.Get("range"))
if err != nil {
httpJSONError(w, fmt.Errorf("invalid query range: %s", err), http.StatusBadRequest)
return
}
step, err := parseDuration(params.Get("step"))
if err != nil {
httpJSONError(w, fmt.Errorf("invalid query resolution: %s", err), http.StatusBadRequest)
return
}
end, err := parseTimestampOrNow(params.Get("end"), api.Now())
if err != nil {
httpJSONError(w, fmt.Errorf("invalid query timestamp: %s", err), http.StatusBadRequest)
return
}
// TODO(julius): Remove this special-case handling a while after PromDash and
// other API consumers have been changed to no longer set "end=0" for setting
// the current time as the end time. Instead, the "end" parameter should
// simply be omitted or set to an empty string for that case.
if end == 0 {
end = api.Now()
}
// For safety, limit the number of returned points per timeseries.
// This is sufficient for 60s resolution for a week or 1h resolution for a year.
if duration/step > 11000 {
err := errors.New("exceeded maximum resolution of 11,000 points per timeseries. Try decreasing the query resolution (?step=XX)")
httpJSONError(w, err, http.StatusBadRequest)
return
}
// Align the start to step "tick" boundary.
end = end.Add(-time.Duration(end.UnixNano() % int64(step)))
start := end.Add(-duration)
query, err := api.QueryEngine.NewRangeQuery(expr, start, end, step)
if err != nil {
httpJSONError(w, err, http.StatusOK)
return
}
matrix, err := query.Exec().Matrix()
if err != nil {
httpJSONError(w, err, http.StatusOK)
return
}
log.Debugf("Range query: %s\nQuery stats:\n%s\n", expr, query.Stats())
httputil.RespondJSON(w, matrix)
}