From e87d3aa740287c107f58724af34d65a60b609897 Mon Sep 17 00:00:00 2001
From: wjHuang <huangwenjun1997@gmail.com>
Date: Mon, 19 Sep 2022 16:25:01 +0800
Subject: [PATCH] metrics, telemetry: add telemetry for metadata lock (#37915)

ref pingcap/tidb#37275
---
 metrics/telemetry.go                 |  3 ++-
 telemetry/data.go                    |  1 +
 telemetry/data_feature_usage.go      | 10 +++++++---
 telemetry/data_feature_usage_test.go |  9 ++++++++-
 4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/metrics/telemetry.go b/metrics/telemetry.go
index ba1374e818..9e76a0f37d 100644
--- a/metrics/telemetry.go
+++ b/metrics/telemetry.go
@@ -327,7 +327,8 @@ func GetLazyPessimisticUniqueCheckSetCounter() int64 {
 
 // DDLUsageCounter records the usages of Add Index with acceleration solution.
 type DDLUsageCounter struct {
-	AddIndexIngestUsed int64 `json:"add_index_Ingest_used"`
+	AddIndexIngestUsed int64 `json:"add_index_ingest_used"`
+	MetadataLockUsed   bool  `json:"metadata_lock_used"`
 }
 
 // Sub returns the difference of two counters.
diff --git a/telemetry/data.go b/telemetry/data.go
index bf2282eb0f..d3dfc06adb 100644
--- a/telemetry/data.go
+++ b/telemetry/data.go
@@ -67,6 +67,7 @@ func postReportTelemetryData() {
 	postReportNonTransactionalCounter()
 	PostSavepointCount()
 	postReportLazyPessimisticUniqueCheckSetCount()
+	postReportDDLUsage()
 }
 
 // PostReportTelemetryDataForTest is for test.
diff --git a/telemetry/data_feature_usage.go b/telemetry/data_feature_usage.go
index d854c56797..3406c60f41 100644
--- a/telemetry/data_feature_usage.go
+++ b/telemetry/data_feature_usage.go
@@ -98,7 +98,7 @@ func getFeatureUsage(ctx context.Context, sctx sessionctx.Context) (*featureUsag
 
 	usage.EnableCostModelVer2 = getCostModelVer2UsageInfo(sctx)
 
-	usage.DDLUsageCounter = getAddIndexIngestUsageInfo()
+	usage.DDLUsageCounter = getDDLUsageInfo(sctx)
 
 	return &usage, nil
 }
@@ -320,7 +320,7 @@ func postReportTablePartitionUsage() {
 	initialTablePartitionCounter = m.ResetTablePartitionCounter(initialTablePartitionCounter)
 }
 
-func postReportAddIndexIngestUsage() {
+func postReportDDLUsage() {
 	initialDDLUsageCounter = m.GetDDLUsageCounter()
 }
 
@@ -366,8 +366,12 @@ func getCostModelVer2UsageInfo(ctx sessionctx.Context) bool {
 func getPagingUsageInfo(ctx sessionctx.Context) bool {
 	return ctx.GetSessionVars().EnablePaging
 }
-func getAddIndexIngestUsageInfo() *m.DDLUsageCounter {
+func getDDLUsageInfo(ctx sessionctx.Context) *m.DDLUsageCounter {
 	curr := m.GetDDLUsageCounter()
 	diff := curr.Sub(initialDDLUsageCounter)
+	isEnable, err := ctx.GetSessionVars().GlobalVarsAccessor.GetGlobalSysVar("tidb_enable_metadata_lock")
+	if err == nil {
+		diff.MetadataLockUsed = isEnable == "ON"
+	}
 	return &diff
 }
diff --git a/telemetry/data_feature_usage_test.go b/telemetry/data_feature_usage_test.go
index 0bc75c4fcd..ed128f553e 100644
--- a/telemetry/data_feature_usage_test.go
+++ b/telemetry/data_feature_usage_test.go
@@ -433,7 +433,11 @@ func TestLazyPessimisticUniqueCheck(t *testing.T) {
 	require.Equal(t, int64(2), usage.LazyUniqueCheckSetCounter)
 }
 
-func TestAddIndexAcceleration(t *testing.T) {
+func TestAddIndexAccelerationAndMDL(t *testing.T) {
+	if !variable.EnableConcurrentDDL.Load() {
+		t.Skipf("test requires concurrent ddl")
+	}
+
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	usage, err := telemetry.GetFeatureUsage(tk.Session())
@@ -450,8 +454,10 @@ func TestAddIndexAcceleration(t *testing.T) {
 	usage, err = telemetry.GetFeatureUsage(tk.Session())
 	require.NoError(t, err)
 	require.Equal(t, int64(0), usage.DDLUsageCounter.AddIndexIngestUsed)
+	require.Equal(t, false, usage.DDLUsageCounter.MetadataLockUsed)
 
 	tk.MustExec("set @@global.tidb_ddl_enable_fast_reorg = on")
+	tk.MustExec("set global tidb_enable_metadata_lock = 1")
 	allow = ddl.IsEnableFastReorg()
 	require.Equal(t, true, allow)
 	usage, err = telemetry.GetFeatureUsage(tk.Session())
@@ -461,4 +467,5 @@ func TestAddIndexAcceleration(t *testing.T) {
 	usage, err = telemetry.GetFeatureUsage(tk.Session())
 	require.NoError(t, err)
 	require.Equal(t, int64(1), usage.DDLUsageCounter.AddIndexIngestUsed)
+	require.Equal(t, true, usage.DDLUsageCounter.MetadataLockUsed)
 }