Improve testing and comments

Signed-off-by: Ruben Vargas <ruben.vp8510@gmail.com>

integration/e2e/api_test.go

@@ -155,11 +155,16 @@ func TestSearchTagValuesV2(t *testing.T) {
 	}
 
 	// Wait to block flushed to backend, 20 seconds is the complete_block_timeout configuration on all in one, we add
-	// 1s for security.
+	// 2s for security.
 	callFlush(t, tempo)
-	time.Sleep(time.Second * 30)
+	time.Sleep(time.Second * 22)
 	callFlush(t, tempo)
 
+	// test metrics
+	require.NoError(t, tempo.WaitSumMetrics(e2e.Equals(1), "tempo_ingester_blocks_flushed_total"))
+	require.NoError(t, tempo.WaitSumMetricsWithOptions(e2e.Equals(1), []string{"tempodb_blocklist_length"}, e2e.WaitMissingMetrics))
+	require.NoError(t, tempo.WaitSumMetrics(e2e.Equals(1), "tempo_ingester_blocks_cleared_total"))
+
 	// Assert no more on the ingester
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
@@ -168,7 +173,7 @@ func TestSearchTagValuesV2(t *testing.T) {
 	}
 
 	// Wait to blocklist_poll to be completed
-	time.Sleep(time.Second * 2)
+	require.NoError(t, tempo.WaitSumMetricsWithOptions(e2e.Equals(1), []string{"tempodb_blocklist_length"}, e2e.WaitMissingMetrics))
 
 	// Assert tags on storage backend
 	now := time.Now()
@@ -239,8 +244,13 @@ func TestSearchTagValues(t *testing.T) {
 	callSearchTagValuesAndAssert(t, tempo, "service.name", searchTagValuesResponse{TagValues: []string{"my-service"}}, 0, 0)
 
 	callFlush(t, tempo)
-	time.Sleep(time.Second * 30)
+	time.Sleep(time.Second * 22)
 	callFlush(t, tempo)
+
+	require.NoError(t, tempo.WaitSumMetrics(e2e.Equals(1), "tempo_ingester_blocks_flushed_total"))
+	require.NoError(t, tempo.WaitSumMetricsWithOptions(e2e.Equals(1), []string{"tempodb_blocklist_length"}, e2e.WaitMissingMetrics))
+	require.NoError(t, tempo.WaitSumMetrics(e2e.Equals(1), "tempo_ingester_blocks_cleared_total"))
+
 	callSearchTagValuesAndAssert(t, tempo, "service.name", searchTagValuesResponse{}, 0, 0)
 	// Assert no more on the ingester
 	// Wait to blocklist_poll to be completed

modules/frontend/tagsharding.go

@@ -66,7 +66,6 @@ type tagResults struct {
 	marshallErr error
 }
 
-
 func (r *tagResultCollector) shouldQuit() bool {
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
@@ -354,8 +353,6 @@ func (s searchTagSharder) buildBackendRequests(ctx context.Context, tenantID str
 
 // ingesterRequest returns a new start and end time range for the backend as well as a http request
 // that covers the ingesters. If nil is returned for the http.Request then there is no ingesters query.
-// since this function modifies searchReq.Start and End we are taking a value instead of a pointer to prevent it from
-// unexpectedly changing the passed searchReq.
 func (s searchTagSharder) ingesterRequest(ctx context.Context, tenantID string, parent *http.Request, searchReq tagSearchReq) (*http.Request, error) {
 	// request without start or end, search only in ingester
 	if searchReq.start() == 0 || searchReq.end() == 0 {