some more stats

cmd/lotus-shed/mempool-stats.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"sort"
 	"time"
 
 	"github.com/ipfs/go-cid"
@@ -58,22 +59,68 @@ var mpoolStatsCmd = &cli.Command{
 					return fmt.Errorf("unrecognized mpool update state: %d", u.Type)
 				}
 			case <-tick:
+				var ages []time.Duration
 				if len(tracker) == 0 {
 					continue
 				}
-				var avg time.Duration
-				var oldest time.Duration
 				for _, v := range tracker {
 					age := time.Since(v.seen)
-					if age > oldest {
-						oldest = age
-					}
-
-					avg += age
+					ages = append(ages, age)
 				}
-				fmt.Printf("%d messages in mempool for average of %s, max=%s\n", len(tracker), avg/time.Duration(len(tracker)), oldest)
+
+				st := ageStats(ages)
+				fmt.Printf("%d messages in mempool for average of %s, (%s / %s / %s)\n", st.Count, st.Average, st.Perc50, st.Perc80, st.Perc95)
 			}
 		}
 		return nil
 	},
 }
+
+type ageStat struct {
+	Average time.Duration
+	Max     time.Duration
+	Perc40  time.Duration
+	Perc50  time.Duration
+	Perc60  time.Duration
+	Perc70  time.Duration
+	Perc80  time.Duration
+	Perc90  time.Duration
+	Perc95  time.Duration
+	Count   int
+}
+
+func ageStats(ages []time.Duration) *ageStat {
+	sort.Slice(ages, func(i, j int) bool {
+		return ages[i] < ages[j]
+	})
+
+	st := ageStat{
+		Count: len(ages),
+	}
+	var sum time.Duration
+	for _, a := range ages {
+		sum += a
+		if a > st.Max {
+			st.Max = a
+		}
+	}
+	st.Average = sum / time.Duration(len(ages))
+
+	p40 := (4 * len(ages)) / 10
+	p50 := len(ages) / 2
+	p60 := (6 * len(ages)) / 10
+	p70 := (7 * len(ages)) / 10
+	p80 := (4 * len(ages)) / 5
+	p90 := (9 * len(ages)) / 10
+	p95 := (19 * len(ages)) / 20
+
+	st.Perc40 = ages[p40]
+	st.Perc50 = ages[p50]
+	st.Perc60 = ages[p60]
+	st.Perc70 = ages[p70]
+	st.Perc80 = ages[p80]
+	st.Perc90 = ages[p90]
+	st.Perc95 = ages[p95]
+
+	return &st
+}