App health: Remove ratelimiter (dapr#8586)

Removes the 1 second app health rate limiter. There is no reason for this
rate limiter to exist.

Signed-off-by: joshvanl <[email protected]>
Co-authored-by: Cassie Coyle <[email protected]>
Co-authored-by: Dapr Bot <[email protected]>

Author: 3 people

pkg/apphealth/health.go

@@ -155,11 +155,6 @@ func (h *AppHealth) ReportHealth(status *Status) {
 		return
 	}
 
-	// Limit health reports to 1 per second
-	if !h.ratelimitReports() {
-		return
-	}
-
 	// Channel is buffered, so make sure that this doesn't block
 	// Just in case another report is being worked on!
 	select {
@@ -205,32 +200,6 @@ func (h *AppHealth) doProbe(parentCtx context.Context) {
 	}
 }
 
-// Returns true if the health report can be saved. Only 1 report per second at most is allowed.
-func (h *AppHealth) ratelimitReports() bool {
-	var (
-		swapped  bool
-		attempts uint8
-	)
-
-	now := h.clock.Now().UnixMicro()
-
-	// Attempts at most 2 times before giving up, as the report may be stale at that point
-	for !swapped && attempts < 2 {
-		attempts++
-
-		// If the last report was less than `reportMinInterval` ago, nothing to do here
-		prev := h.lastReport.Load()
-		if prev > now-reportMinInterval.Microseconds() {
-			return false
-		}
-
-		swapped = h.lastReport.CompareAndSwap(prev, now)
-	}
-
-	// If we couldn't do the swap after 2 attempts, just return false
-	return swapped
-}
-
 func (h *AppHealth) setResult(ctx context.Context, status *Status) {
 	h.lastReport.Store(h.clock.Now().UnixMicro())
 

pkg/apphealth/health_test.go

@@ -121,56 +121,6 @@ func TestAppHealth_setResult(t *testing.T) {
 	assert.Equal(t, threshold+3, h.failureCount.Load())
 }
 
-func TestAppHealth_ratelimitReports(t *testing.T) {
-	clock := clocktesting.NewFakeClock(time.Now())
-	h := New(config.AppHealthConfig{}, nil)
-	h.clock = clock
-
-	// First run should always succeed
-	require.True(t, h.ratelimitReports())
-
-	// Run again without waiting
-	require.False(t, h.ratelimitReports())
-	require.False(t, h.ratelimitReports())
-
-	// Step and test
-	clock.Step(reportMinInterval)
-	require.True(t, h.ratelimitReports())
-	require.False(t, h.ratelimitReports())
-
-	// Run tests for 1 second, constantly
-	// Should succeed only 10 times.
-	clock.Step(reportMinInterval)
-	firehose := func(start time.Time, step time.Duration) (passed int64) {
-		for clock.Now().Sub(start) < time.Second*10 {
-			if h.ratelimitReports() {
-				passed++
-			}
-			clock.Step(step)
-		}
-		return passed
-	}
-
-	passed := firehose(clock.Now(), 10*time.Millisecond)
-	assert.Equal(t, int64(10), passed)
-
-	// Repeat, but run with 3 parallel goroutines
-	wg := sync.WaitGroup{}
-	totalPassed := atomic.Int64{}
-	start := clock.Now()
-	wg.Add(3)
-	for range 3 {
-		go func() {
-			totalPassed.Add(firehose(start, 3*time.Millisecond))
-			wg.Done()
-		}()
-	}
-	wg.Wait()
-	passed = totalPassed.Load()
-	assert.GreaterOrEqual(t, passed, int64(8))
-	assert.LessOrEqual(t, passed, int64(12))
-}
-
 func Test_StartProbes(t *testing.T) {
 	t.Run("closing context should return", func(t *testing.T) {
 		ctx, cancel := context.WithCancel(t.Context())

pkg/apphealth/status.go

@@ -16,11 +16,6 @@ package apphealth
 
 import "time"
 
-const (
-	// reportMinInterval is the minimum interval between health reports.
-	reportMinInterval = time.Second
-)
-
 type Status struct {
 	IsHealthy bool    `json:"ishealthy"`
 	TimeUnix  int64   `json:"timeUnix"`