// Query handles the /api/query endpoint.
func (serv MetricsService) Query(w http.ResponseWriter, r *http.Request) {
setAccessControlHeaders(w)
params := httputils.GetQueryParams(r)
expr := params.Get("expr")
asText := params.Get("asText")
var format ast.OutputFormat
// BUG(julius): Use Content-Type negotiation.
if asText == "" {
format = ast.JSON
w.Header().Set("Content-Type", "application/json")
} else {
format = ast.Text
w.Header().Set("Content-Type", "text/plain")
}
exprNode, err := rules.LoadExprFromString(expr)
if err != nil {
fmt.Fprint(w, ast.ErrorToJSON(err))
return
}
timestamp := clientmodel.TimestampFromTime(serv.time.Now())
queryStats := stats.NewTimerGroup()
result := ast.EvalToString(exprNode, timestamp, format, serv.Storage, queryStats)
glog.V(1).Infof("Instant query: %s\nQuery stats:\n%s\n", expr, queryStats)
fmt.Fprint(w, result)
}
// SetTargets handles the /api/targets endpoint.
func (serv MetricsService) SetTargets(w http.ResponseWriter, r *http.Request) {
params := httputils.GetQueryParams(r)
jobName := params.Get("job")
decoder := json.NewDecoder(r.Body)
var targetGroups []TargetGroup
err := decoder.Decode(&targetGroups)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
job := serv.Config.GetJobByName(jobName)
if job == nil {
http.Error(w, "job not found", http.StatusNotFound)
return
}
newTargets := []retrieval.Target{}
for _, targetGroup := range targetGroups {
// Do mandatory map type conversion due to Go shortcomings.
baseLabels := clientmodel.LabelSet{
clientmodel.JobLabel: clientmodel.LabelValue(job.GetName()),
}
for label, value := range targetGroup.BaseLabels {
baseLabels[clientmodel.LabelName(label)] = clientmodel.LabelValue(value)
}
for _, endpoint := range targetGroup.Endpoints {
newTarget := retrieval.NewTarget(endpoint, job.ScrapeTimeout(), baseLabels)
newTargets = append(newTargets, newTarget)
}
}
// BUG(julius): Validate that this ScrapeInterval is in fact the proper one
// for the job.
serv.TargetManager.ReplaceTargets(*job, newTargets)
}
// QueryRange handles the /api/query_range endpoint.
func (serv MetricsService) QueryRange(w http.ResponseWriter, r *http.Request) {
setAccessControlHeaders(w)
w.Header().Set("Content-Type", "application/json")
params := httputils.GetQueryParams(r)
expr := params.Get("expr")
// Input times and durations are in seconds and get converted to nanoseconds.
endFloat, _ := strconv.ParseFloat(params.Get("end"), 64)
durationFloat, _ := strconv.ParseFloat(params.Get("range"), 64)
stepFloat, _ := strconv.ParseFloat(params.Get("step"), 64)
nanosPerSecond := int64(time.Second / time.Nanosecond)
end := int64(endFloat) * nanosPerSecond
duration := int64(durationFloat) * nanosPerSecond
step := int64(stepFloat) * nanosPerSecond
exprNode, err := rules.LoadExprFromString(expr)
if err != nil {
fmt.Fprint(w, ast.ErrorToJSON(err))
return
}
if exprNode.Type() != ast.VectorType {
fmt.Fprint(w, ast.ErrorToJSON(errors.New("expression does not evaluate to vector type")))
return
}
if end == 0 {
end = clientmodel.Now().UnixNano()
}
if step <= 0 {
step = nanosPerSecond
}
if end-duration < 0 {
duration = end
}
// 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 {
fmt.Fprint(w, ast.ErrorToJSON(errors.New("exceeded maximum resolution of 11,000 points per timeseries. Try decreasing the query resolution (?step=XX)")))
return
}
// Align the start to step "tick" boundary.
end -= end % step
queryStats := stats.NewTimerGroup()
evalTimer := queryStats.GetTimer(stats.TotalEvalTime).Start()
matrix, err := ast.EvalVectorRange(
exprNode.(ast.VectorNode),
clientmodel.TimestampFromUnixNano(end-duration),
clientmodel.TimestampFromUnixNano(end),
time.Duration(step),
serv.Storage,
queryStats)
if err != nil {
fmt.Fprint(w, ast.ErrorToJSON(err))
return
}
evalTimer.Stop()
sortTimer := queryStats.GetTimer(stats.ResultSortTime).Start()
sort.Sort(matrix)
sortTimer.Stop()
jsonTimer := queryStats.GetTimer(stats.JSONEncodeTime).Start()
result := ast.TypedValueToJSON(matrix, "matrix")
jsonTimer.Stop()
glog.V(1).Infof("Range query: %s\nQuery stats:\n%s\n", expr, queryStats)
fmt.Fprint(w, result)
}