scrape: address comments on PR

Signed-off-by: Ridwan Sharif <ridwanmsharif@google.com>

scrape/manager.go

@@ -149,9 +149,8 @@ type Options struct {
 	// because of an early startup scrape.
 	InitialScrapeOffset time.Duration
 
-	// private options for testability.
+	// private option for testability.
 	skipJitterOffsetting bool
-	offsetSeed           uint64
 }
 
 // Manager maintains a set of scrape pools and manages start/stop cycles
@@ -270,11 +269,6 @@ func (m *Manager) reload() {
 
 // setOffsetSeed calculates a global offsetSeed per server relying on extra label set.
 func (m *Manager) setOffsetSeed(labels labels.Labels) error {
-	if m.opts.offsetSeed != 0 {
-		m.offsetSeed = m.opts.offsetSeed
-		return nil
-	}
-
 	h := fnv.New64a()
 	hostname, err := osutil.GetFQDN()
 	if err != nil {

scrape/scrape.go

@@ -1253,9 +1253,8 @@ func (sl *scrapeLoop) getScrapeOffset() time.Duration {
 
 func (sl *scrapeLoop) run(errc chan<- error) {
 	var (
-		last              time.Time
-		alignedScrapeTime = time.Now().Round(0)
-		ticker            = time.NewTicker(sl.interval)
+		last   time.Time
+		ticker = time.NewTicker(sl.interval)
 	)
 	defer func() {
 		if sl.scrapeOnShutdown {
@@ -1284,6 +1283,7 @@ func (sl *scrapeLoop) run(errc chan<- error) {
 
 	// Reset the ticker so target scrape times are aligned to the offset+intervals.
 	ticker.Reset(sl.interval)
+	alignedScrapeTime := time.Now().Round(0)
 
 	for {
 		select {

scrape/scrape_test.go

@@ -6823,7 +6823,6 @@ func TestScrapeOffsetDistribution(t *testing.T) {
 
 		app := teststorage.NewAppendable()
 		opts := &Options{
-			offsetSeed: 1,
 			HTTPClientOptions: []config_util.HTTPClientOption{
 				config_util.WithDialContextFunc(func(ctx context.Context, _, _ string) (net.Conn, error) {
 					srvConn, cliConn := net.Pipe()
@@ -6839,6 +6838,7 @@ func TestScrapeOffsetDistribution(t *testing.T) {
 			},
 		}
 		scrapeManager, err := NewManager(opts, promslog.NewNopLogger(), nil, app, nil, prometheus.NewRegistry())
+		scrapeManager.offsetSeed = 1 // Set a fixed offset seed for deterministic testing.
 		require.NoError(t, err)
 
 		var targets []model.LabelSet