feat: use check statuses 1h/1d summary to get the best window for

check_statuses

[skip ci]

Author: adityathebe

query/check_details.go

@@ -14,12 +14,32 @@ import (
 	"github.com/samber/lo"
 )
 
-var (
+const (
 	// Maximum number of past checks in the in-memory cache
 	DefaultCacheCount = 5
 
 	// Default search window
 	DefaultCheckQueryWindow = "1h"
+
+	// The number of data points that should be strived for
+	// when aggregating check statuses.
+	desiredNumOfCheckStatuses = 100
+)
+
+var (
+	// allowed list of window durations that are used when aggregating check statuses.
+	allowedWindows = []time.Duration{
+		time.Minute,        // 1m
+		time.Minute * 5,    // 5m
+		time.Minute * 15,   // 15m
+		time.Minute * 30,   // 30m
+		time.Hour,          // 1h
+		time.Hour * 3,      // 3h
+		time.Hour * 6,      // 6h
+		time.Hour * 12,     // 12h
+		time.Hour * 24,     // 24h
+		time.Hour * 24 * 7, // 1w
+	}
 )
 
 type Timeseries struct {
@@ -138,10 +158,84 @@ func (q CheckQueryParams) GetWhereClause() (string, map[string]interface{}, erro
 	return strings.TrimSpace(clause), args, nil
 }
 
-func (q CheckQueryParams) ExecuteDetails(ctx context.Context) ([]Timeseries, types.Uptime, types.Latency, error) {
+func getBestPartitioner(totalChecks int, rangeDuration time.Duration) time.Duration {
+	if totalChecks <= desiredNumOfCheckStatuses {
+		return 0 // No need to perform window aggregation
+	}
+
+	bestDelta := 100000000 // sufficiently large delta to begin with
+	bestWindow := allowedWindows[0]
+
+	for _, wp := range allowedWindows {
+		numWindows := int(rangeDuration / wp)
+		delta := abs(desiredNumOfCheckStatuses - numWindows)
+
+		if delta < bestDelta {
+			bestDelta = delta
+			bestWindow = wp
+		} else {
+			// as soon as we notice that the delta gets worse, we break the loop
+			break
+		}
+	}
+
+	numWindows := int(rangeDuration / bestWindow)
+	if abs(desiredNumOfCheckStatuses-totalChecks) <= abs(desiredNumOfCheckStatuses-numWindows) {
+		// If this best partition creates windows such that the resulting number of data points deviate more
+		// from the desired data points than the actual data points, then we do not aggregate.
+		// Example: if there are 144 checks for the duration of 6 days,
+		// then the best partition, 1 hour, would generate 144 data points.
+		// But the original data points (120) are closer to 100, so we do not aggregate.
+		return 0
+	}
+
+	return bestWindow
+}
+
+func optimalWindow(ctx context.Context, from, to time.Time) (time.Duration, error) {
+	var view string
+	timeRange := to.Sub(from)
+	if timeRange > time.Hour*24*21 {
+		view = "check_statuses_1d"
+	} else if timeRange > time.Hour*48 {
+		view = "check_statuses_1h"
+	} else {
+		return -1, nil //
+	}
+
+	q := fmt.Sprintf(`
+	SELECT
+		SUM(total) AS total,
+		MAX(created_at) AS latest,
+		MIN(created_at) AS earliest
+	FROM
+		%s
+	WHERE
+		created_at >= ? AND created_at <= ?;`, view)
+	var total *int
+	var latest, earliest *time.Time
+	if err := ctx.DB().Raw(q, from, to).Row().Scan(&total, &latest, &earliest); err != nil {
+		return 0, err
+	}
+	if total == nil {
+		return -1, nil //
+	}
+
+	return getBestPartitioner(*total, earliest.Sub(*latest)), nil
+}
+
+func CheckStatuses(ctx context.Context, q CheckQueryParams) ([]Timeseries, types.Uptime, types.Latency, error) {
 	start := q.GetStartTime().Format(time.RFC3339)
 	end := q.GetEndTime().Format(time.RFC3339)
 
+	// For the given ranges try to find the best window using check statuses summary
+	window, err := optimalWindow(ctx, *q.GetStartTime(), *q.GetEndTime())
+	if err != nil {
+		return nil, types.Uptime{}, types.Latency{}, err
+	} else if window >= 0 {
+		q.WindowDuration = window
+	}
+
 	query := `
 With grouped_by_window AS (
 	SELECT
@@ -309,3 +403,14 @@ func parseDuration(d string, name string) (clause string, arg interface{}, err e
 	}
 	return "", nil, fmt.Errorf("start time must be a duration or RFC3339 timestamp")
 }
+
+// abs returns the absolute value of i.
+// math.Abs only supports float64 and this avoids the needless type conversions
+// and ugly expression.
+func abs(n int) int {
+	if n > 0 {
+		return n
+	}
+
+	return -n
+}

tests/fixtures/dummy/check_statuses.go

@@ -6,7 +6,7 @@ import (
 	"github.com/flanksource/duty/models"
 )
 
-func generateStatus(check models.Check, t time.Time, count int, passingMod int) []models.CheckStatus {
+func generateStatus(check models.Check, t time.Time, schedule time.Duration, count int, passingMod int) []models.CheckStatus {
 	var statuses = []models.CheckStatus{}
 
 	for i := 0; i < count; i++ {
@@ -27,9 +27,9 @@ func generateStatus(check models.Check, t time.Time, count int, passingMod int)
 
 func AllDummyCheckStatuses() []models.CheckStatus {
 	statuses := append(
-		generateStatus(LogisticsAPIHealthHTTPCheck, CurrentTime, 70, 5),
-		generateStatus(DeletedCheck, CurrentTime, 1, 1)[0],
-		generateStatus(DeletedCheckOld, *DeletedCheckOld.CreatedAt, 1, 1)[0],
+		generateStatus(LogisticsAPIHealthHTTPCheck, CurrentTime, time.Minute, 70, 5),
+		generateStatus(DeletedCheck, CurrentTime, time.Minute, 1, 1)[0],
+		generateStatus(DeletedCheckOld, *DeletedCheckOld.CreatedAt, time.Minute, 1, 1)[0],
 		models.CheckStatus{
 			CheckID:   LogisticsAPIHomeHTTPCheck.ID,
 			Duration:  100,
@@ -46,12 +46,12 @@ func AllDummyCheckStatuses() []models.CheckStatus {
 		},
 	)
 
-	statuses = append(statuses, generateStatus(DeletedCheck1h, CurrentTime.Add(-15*time.Minute), 1, 1)[0])
-	statuses = append(statuses, generateStatus(DeletedCheck1h, CurrentTime.Add(-2*time.Hour), 10, 2)...)
+	statuses = append(statuses, generateStatus(DeletedCheck1h, CurrentTime.Add(-15*time.Minute), time.Minute, 1, 1)[0])
+	statuses = append(statuses, generateStatus(DeletedCheck1h, CurrentTime.Add(-2*time.Hour), time.Minute, 10, 2)...)
 
 	// Check statuses from 2022-01-01
 	// not dervied from current time for consistency
-	statuses = append(statuses, generateStatus(CartAPIHeathCheckAgent, time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC), 70, 5)...)
+	statuses = append(statuses, generateStatus(CartAPIHeathCheckAgent, time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC), time.Minute*5, 1440, 5)...) // 1440 check statuses spanning 5 days
 
 	return statuses
 }

tests/query_check_details_test.go

@@ -13,7 +13,7 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-var _ = ginkgo.Describe("CheckDetails", ginkgo.Ordered, func() {
+var _ = ginkgo.Describe("CheckDetails", ginkgo.Ordered, ginkgo.Focus, func() {
 	type testRecord struct {
 		since    string
 		statuses int
@@ -48,7 +48,7 @@ var _ = ginkgo.Describe("CheckDetails", ginkgo.Ordered, func() {
 			err = q.Init(urlParam)
 			Expect(err).To(BeNil())
 
-			ts, uptime, latency, err := q.ExecuteDetails(DefaultContext)
+			ts, uptime, latency, err := query.CheckStatuses(DefaultContext, q)
 			Expect(err).To(BeNil())
 
 			Expect(len(ts)).To(Equal(td.statuses), "unexpected number of results")

tests/setup/common.go

@@ -122,6 +122,14 @@ func BeforeSuiteFn(args ...interface{}) context.Context {
 		logger.Infof("Created dummy data %v", len(dummyData.Checks))
 	}
 
+	if err, _ := job.AggregateCheckStatus1d(DefaultContext); err != nil {
+		panic(err.Error())
+	}
+
+	if err, _ := job.AggregateCheckStatus1h(DefaultContext); err != nil {
+		panic(err.Error())
+	}
+
 	DefaultContext := DefaultContext.WithKubernetes(fake.NewSimpleClientset(&v1.ConfigMap{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      "test-cm",