planner: add more metrics for binding (#51739)

ref #51347

Author: qw4990

pkg/bindinfo/BUILD.bazel

@@ -71,7 +71,6 @@ go_test(
         "//pkg/bindinfo/norm",
         "//pkg/config",
         "//pkg/domain",
-        "//pkg/metrics",
         "//pkg/parser",
         "//pkg/parser/ast",
         "//pkg/parser/auth",
@@ -90,7 +89,6 @@ go_test(
         "//pkg/util/stmtsummary",
         "@com_github_ngaut_pools//:pools",
         "@com_github_pingcap_failpoint//:failpoint",
-        "@com_github_prometheus_client_model//go",
         "@com_github_stretchr_testify//require",
         "@io_opencensus_go//stats/view",
         "@org_uber_go_goleak//:goleak",

pkg/bindinfo/binding_cache.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/pingcap/tidb/pkg/bindinfo/internal/logutil"
 	"github.com/pingcap/tidb/pkg/bindinfo/norm"
+	"github.com/pingcap/tidb/pkg/metrics"
 	"github.com/pingcap/tidb/pkg/parser"
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/sessionctx"
@@ -84,11 +85,21 @@ func newFuzzyBindingCache(loadBindingFromStorageFunc func(sessionctx.Context, st
 	}
 }
 
+func (fbc *fuzzyBindingCache) shouldMetric() bool {
+	return fbc.loadBindingFromStorageFunc != nil // only metric for GlobalBindingCache, whose loadBindingFromStorageFunc is not nil.
+}
+
 func (fbc *fuzzyBindingCache) FuzzyMatchingBinding(sctx sessionctx.Context, fuzzyDigest string, tableNames []*ast.TableName) (matchedBinding Binding, isMatched bool) {
 	matchedBinding, isMatched, missingSQLDigest := fbc.getFromMemory(sctx, fuzzyDigest, tableNames)
 	if len(missingSQLDigest) == 0 {
+		if fbc.shouldMetric() && isMatched {
+			metrics.BindingCacheHitCounter.Inc()
+		}
 		return
 	}
+	if fbc.shouldMetric() {
+		metrics.BindingCacheMissCounter.Inc()
+	}
 	if fbc.loadBindingFromStorageFunc == nil {
 		return
 	}

pkg/bindinfo/global_handle.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/errors"
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/tidb/pkg/bindinfo/internal/logutil"
+	"github.com/pingcap/tidb/pkg/metrics"
 	"github.com/pingcap/tidb/pkg/parser"
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/format"
@@ -210,6 +211,10 @@ func (h *globalBindingHandle) LoadFromStorageToCache(fullLoad bool) (err error)
 		defer func() {
 			h.setLastUpdateTime(lastUpdateTime)
 			h.setCache(newCache)
+
+			metrics.BindingCacheMemUsage.Set(float64(h.GetMemUsage()))
+			metrics.BindingCacheMemLimit.Set(float64(h.GetMemCapacity()))
+			metrics.BindingCacheNumBindings.Set(float64(h.Size()))
 		}()
 
 		for _, row := range rows {

pkg/bindinfo/session_handle_test.go

@@ -23,13 +23,11 @@ import (
 	"github.com/pingcap/tidb/pkg/bindinfo"
 	"github.com/pingcap/tidb/pkg/bindinfo/internal"
 	"github.com/pingcap/tidb/pkg/bindinfo/norm"
-	"github.com/pingcap/tidb/pkg/metrics"
 	"github.com/pingcap/tidb/pkg/parser"
 	"github.com/pingcap/tidb/pkg/parser/auth"
 	"github.com/pingcap/tidb/pkg/server"
 	"github.com/pingcap/tidb/pkg/testkit"
 	"github.com/pingcap/tidb/pkg/util/stmtsummary"
-	dto "github.com/prometheus/client_model/go"
 	"github.com/stretchr/testify/require"
 )
 
@@ -48,14 +46,6 @@ func TestGlobalAndSessionBindingBothExist(t *testing.T) {
 
 	tk.MustExec("create global binding for SELECT * from t1,t2 where t1.id = t2.id using SELECT  /*+ TIDB_SMJ(t1, t2) */  * from t1,t2 where t1.id = t2.id")
 
-	// Test bindingUsage, which indicates how many times the binding is used.
-	metrics.BindUsageCounter.Reset()
-	tk.MustHavePlan("SELECT * from t1,t2 where t1.id = t2.id", "MergeJoin")
-	pb := &dto.Metric{}
-	err := metrics.BindUsageCounter.WithLabelValues(metrics.ScopeGlobal).Write(pb)
-	require.NoError(t, err)
-	require.Equal(t, float64(1), pb.GetCounter().GetValue())
-
 	// Test 'tidb_use_plan_baselines'
 	tk.MustExec("set @@tidb_use_plan_baselines = 0")
 	tk.MustHavePlan("SELECT * from t1,t2 where t1.id = t2.id", "HashJoin")

pkg/metrics/bindinfo.go

@@ -18,16 +18,48 @@ import "github.com/prometheus/client_golang/prometheus"
 
 // bindinfo metrics.
 var (
-	BindUsageCounter *prometheus.CounterVec
+	BindingCacheHitCounter  prometheus.Counter
+	BindingCacheMissCounter prometheus.Counter
+	BindingCacheMemUsage    prometheus.Gauge
+	BindingCacheMemLimit    prometheus.Gauge
+	BindingCacheNumBindings prometheus.Gauge
 )
 
 // InitBindInfoMetrics initializes bindinfo metrics.
 func InitBindInfoMetrics() {
-	BindUsageCounter = NewCounterVec(
+	BindingCacheHitCounter = NewCounter(
 		prometheus.CounterOpts{
 			Namespace: "tidb",
-			Subsystem: "bindinfo",
-			Name:      "bind_usage_counter",
-			Help:      "Counter of query using sql bind",
-		}, []string{LabelScope})
+			Subsystem: "server",
+			Name:      "binding_cache_hit_total",
+			Help:      "Counter of binding cache hit.",
+		})
+	BindingCacheMissCounter = NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "binding_cache_miss_total",
+			Help:      "Counter of binding cache miss.",
+		})
+	BindingCacheMemUsage = NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "binding_cache_mem_usage",
+			Help:      "Memory usage of binding cache.",
+		})
+	BindingCacheMemLimit = NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "binding_cache_mem_limit",
+			Help:      "Memory limit of binding cache.",
+		})
+	BindingCacheNumBindings = NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "binding_cache_num_bindings",
+			Help:      "Number of bindings in binding cache.",
+		})
 }