cloudflare/pint
Publicmirrored from https://github.com/cloudflare/pintAvailable
internal/promapi/range.go
107lines · modecode
| 1 | package promapi |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | "net" |
| 8 | "strings" |
| 9 | "time" |
| 10 | |
| 11 | v1 "github.com/prometheus/client_golang/api/prometheus/v1" |
| 12 | "github.com/prometheus/common/model" |
| 13 | "github.com/rs/zerolog/log" |
| 14 | ) |
| 15 | |
| 16 | type RangeQueryResult struct { |
| 17 | Samples []*model.SampleStream |
| 18 | Start time.Time |
| 19 | End time.Time |
| 20 | DurationSeconds float64 |
| 21 | } |
| 22 | |
| 23 | func (p *Prometheus) RangeQuery(ctx context.Context, expr string, start, end time.Time, step time.Duration) (*RangeQueryResult, error) { |
| 24 | log.Debug(). |
| 25 | Str("uri", p.uri). |
| 26 | Str("query", expr). |
| 27 | Time("start", start). |
| 28 | Time("end", end). |
| 29 | Str("step", HumanizeDuration(step)). |
| 30 | Msg("Scheduling prometheus range query") |
| 31 | |
| 32 | lockKey := "/api/v1/query/range" |
| 33 | p.lock.lock(lockKey) |
| 34 | |
| 35 | cacheKey := strings.Join([]string{expr, start.String(), end.String(), step.String()}, "\n") |
| 36 | if v, ok := p.cache.Get(cacheKey); ok { |
| 37 | log.Debug().Str("key", cacheKey).Str("uri", p.uri).Msg("Range query cache hit") |
| 38 | r := v.(RangeQueryResult) |
| 39 | p.lock.unlock((lockKey)) |
| 40 | return &r, nil |
| 41 | } |
| 42 | |
| 43 | rctx, cancel := context.WithTimeout(ctx, p.timeout) |
| 44 | defer cancel() |
| 45 | |
| 46 | prometheusQueriesTotal.WithLabelValues(p.name, "/api/v1/query_range").Inc() |
| 47 | r := v1.Range{ |
| 48 | Start: start, |
| 49 | End: end, |
| 50 | Step: step, |
| 51 | } |
| 52 | qstart := time.Now() |
| 53 | result, _, err := p.api.QueryRange(rctx, expr, r) |
| 54 | duration := time.Since(qstart) |
| 55 | p.lock.unlock((lockKey)) |
| 56 | log.Debug(). |
| 57 | Str("uri", p.uri). |
| 58 | Str("query", expr). |
| 59 | Str("duration", HumanizeDuration(duration)). |
| 60 | Msg("Range query completed") |
| 61 | if err != nil { |
| 62 | log.Error().Err(err).Str("uri", p.uri).Str("query", expr).Msg("Range query failed") |
| 63 | prometheusQueryErrorsTotal.WithLabelValues(p.name, "/api/v1/query_range", errReason(err)).Inc() |
| 64 | if delta, retryOK := canRetry(err, end.Sub(start)); retryOK { |
| 65 | if delta < step*2 { |
| 66 | log.Error().Str("uri", p.uri).Str("query", expr).Msg("No more retries possible") |
| 67 | return nil, errors.New("no more retries possible") |
| 68 | } |
| 69 | log.Warn().Str("delta", HumanizeDuration(delta)).Msg("Retrying request with smaller range") |
| 70 | return p.RangeQuery(ctx, expr, start.Add(delta), end, step) |
| 71 | } |
| 72 | return nil, err |
| 73 | } |
| 74 | |
| 75 | qr := RangeQueryResult{ |
| 76 | DurationSeconds: duration.Seconds(), |
| 77 | Start: start, |
| 78 | End: end, |
| 79 | } |
| 80 | |
| 81 | switch result.Type() { |
| 82 | case model.ValMatrix: |
| 83 | samples := result.(model.Matrix) |
| 84 | qr.Samples = samples |
| 85 | default: |
| 86 | log.Error().Err(err).Str("uri", p.uri).Str("query", expr).Msgf("Range query returned unknown result type: %v", result.Type()) |
| 87 | prometheusQueryErrorsTotal.WithLabelValues(p.name, "/api/v1/query_range", "unknown result type").Inc() |
| 88 | return nil, fmt.Errorf("unknown result type: %v", result.Type()) |
| 89 | } |
| 90 | log.Debug().Str("uri", p.uri).Str("query", expr).Int("samples", len(qr.Samples)).Msg("Parsed range response") |
| 91 | |
| 92 | log.Debug().Str("query", expr).Str("uri", p.uri).Msg("Range query cache miss") |
| 93 | p.cache.Add(cacheKey, qr) |
| 94 | |
| 95 | return &qr, nil |
| 96 | } |
| 97 | |
| 98 | func canRetry(err error, delta time.Duration) (time.Duration, bool) { |
| 99 | var neterr net.Error |
| 100 | if ok := errors.As(err, &neterr); ok && neterr.Timeout() { |
| 101 | return delta / 2, true |
| 102 | } |
| 103 | if strings.Contains(err.Error(), "query processing would load too many samples into memory in ") { |
| 104 | return (delta / 4) * 3, true |
| 105 | } |
| 106 | return delta, false |
| 107 | } |
| 108 | |