metrics: add metrics for bind info

bindinfo/bind_test.go

@@ -19,21 +19,22 @@ import (
 	"fmt"
 	"os"
 	"testing"
-	"time"
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser"
 	"github.com/pingcap/tidb/bindinfo"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta/autoid"
+	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/store/mockstore"
 	"github.com/pingcap/tidb/store/mockstore/mocktikv"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/testkit"
 	"github.com/pingcap/tidb/util/testleak"
+	dto "github.com/prometheus/client_model/go"
 )
 
 func TestT(t *testing.T) {
@@ -146,13 +147,21 @@ func (s *testSuite) TestGlobalBinding(c *C) {
 	tk.MustExec("create table t1(i int, s varchar(20))")
 	tk.MustExec("create index index_t on t(i,s)")
 
+	metrics.BindTotalGauge.Reset()
+	metrics.BindMemoryUsage.Reset()
+
 	_, err := tk.Exec("create global binding for select * from t where i>100 using select * from t use index(index_t) where i>100")
 	c.Assert(err, IsNil, Commentf("err %v", err))
 
-	time.Sleep(time.Second * 1)
 	_, err = tk.Exec("create global binding for select * from t where i>99 using select * from t use index(index_t) where i>99")
 	c.Assert(err, IsNil)
 
+	pb := &dto.Metric{}
+	metrics.BindTotalGauge.WithLabelValues(metrics.ScopeGlobal, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(1))
+	metrics.BindMemoryUsage.WithLabelValues(metrics.ScopeGlobal, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(161))
+
 	sql, hash := parser.NormalizeDigest("select * from t where i > ?")
 
 	bindData := s.domain.BindHandle().GetBindRecord(hash, sql, "test")
@@ -203,6 +212,12 @@ func (s *testSuite) TestGlobalBinding(c *C) {
 	bindData = s.domain.BindHandle().GetBindRecord(hash, sql, "test")
 	c.Check(bindData, IsNil)
 
+	metrics.BindTotalGauge.WithLabelValues(metrics.ScopeGlobal, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(0))
+	metrics.BindMemoryUsage.WithLabelValues(metrics.ScopeGlobal, bindinfo.Using).Write(pb)
+	// From newly created global bind handle.
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(161))
+
 	bindHandle = bindinfo.NewBindHandle(tk.Se)
 	err = bindHandle.Update(true)
 	c.Check(err, IsNil)
@@ -235,13 +250,21 @@ func (s *testSuite) TestSessionBinding(c *C) {
 	tk.MustExec("create table t1(i int, s varchar(20))")
 	tk.MustExec("create index index_t on t(i,s)")
 
+	metrics.BindTotalGauge.Reset()
+	metrics.BindMemoryUsage.Reset()
+
 	_, err := tk.Exec("create session binding for select * from t where i>100 using select * from t use index(index_t) where i>100")
 	c.Assert(err, IsNil, Commentf("err %v", err))
 
-	time.Sleep(time.Second * 1)
 	_, err = tk.Exec("create session binding for select * from t where i>99 using select * from t use index(index_t) where i>99")
 	c.Assert(err, IsNil)
 
+	pb := &dto.Metric{}
+	metrics.BindTotalGauge.WithLabelValues(metrics.ScopeSession, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(1))
+	metrics.BindMemoryUsage.WithLabelValues(metrics.ScopeSession, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(161))
+
 	handle := tk.Se.Value(bindinfo.SessionBindInfoKeyType).(*bindinfo.SessionHandle)
 	bindData := handle.GetBindRecord("select * from t where i > ?", "test")
 	c.Check(bindData, NotNil)
@@ -283,6 +306,11 @@ func (s *testSuite) TestSessionBinding(c *C) {
 	c.Check(bindData, NotNil)
 	c.Check(bindData.OriginalSQL, Equals, "select * from t where i > ?")
 	c.Check(bindData.Status, Equals, "deleted")
+
+	metrics.BindTotalGauge.WithLabelValues(metrics.ScopeSession, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(0))
+	metrics.BindMemoryUsage.WithLabelValues(metrics.ScopeSession, bindinfo.Using).Write(pb)
+	c.Assert(pb.GetGauge().GetValue(), Equals, float64(0))
 }
 
 func (s *testSuite) TestGlobalAndSessionBindingBothExist(c *C) {
@@ -318,6 +346,7 @@ func (s *testSuite) TestGlobalAndSessionBindingBothExist(c *C) {
 
 	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")
 
+	metrics.BindUsageCounter.Reset()
 	tk.MustQuery("explain SELECT * from t1,t2 where t1.id = t2.id").Check(testkit.Rows(
 		"MergeJoin_7 12487.50 root inner join, left key:test.t1.id, right key:test.t2.id",
 		"├─Sort_11 9990.00 root test.t1.id:asc",
@@ -329,6 +358,9 @@ func (s *testSuite) TestGlobalAndSessionBindingBothExist(c *C) {
 		"    └─Selection_13 9990.00 cop not(isnull(test.t2.id))",
 		"      └─TableScan_12 10000.00 cop table:t2, range:[-inf,+inf], keep order:false, stats:pseudo",
 	))
+	pb := &dto.Metric{}
+	metrics.BindUsageCounter.WithLabelValues(metrics.ScopeGlobal).Write(pb)
+	c.Assert(pb.GetCounter().GetValue(), Equals, float64(1))
 
 	tk.MustExec("drop global binding for SELECT * from t1,t2 where t1.id = t2.id")
 

bindinfo/cache.go

@@ -14,7 +14,10 @@
 package bindinfo
 
 import (
+	"unsafe"
+
 	"github.com/pingcap/parser/ast"
+	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
 )
@@ -64,3 +67,19 @@ func newBindRecord(row chunk.Row) *BindRecord {
 		Collation:   row.GetString(7),
 	}
 }
+
+// size calculates the memory size of a bind meta.
+func (m *BindRecord) size() float64 {
+	res := len(m.OriginalSQL) + len(m.BindSQL) + len(m.Db) + len(m.Status) + 2*int(unsafe.Sizeof(m.CreateTime)) + len(m.Charset) + len(m.Collation)
+	return float64(res)
+}
+
+func (m *BindRecord) updateMetrics(scope string, inc bool) {
+	if inc {
+		metrics.BindMemoryUsage.WithLabelValues(scope, m.Status).Add(float64(m.size()))
+		metrics.BindTotalGauge.WithLabelValues(scope, m.Status).Inc()
+	} else {
+		metrics.BindMemoryUsage.WithLabelValues(scope, m.Status).Sub(float64(m.size()))
+		metrics.BindTotalGauge.WithLabelValues(scope, m.Status).Dec()
+	}
+}

bindinfo/handle.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
+	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/store/tikv/oracle"
 	"github.com/pingcap/tidb/types"
@@ -123,9 +124,10 @@ func (h *BindHandle) Update(fullLoad bool) (err error) {
 			continue
 		}
 
-		newCache.removeStaleBindMetas(hash, meta)
+		newCache.removeStaleBindMetas(hash, meta, metrics.ScopeGlobal)
 		if meta.Status == Using {
 			newCache[hash] = append(newCache[hash], meta)
+			metrics.BindMemoryUsage.WithLabelValues(metrics.ScopeGlobal, meta.Status).Add(meta.size())
 		}
 	}
 	return nil
@@ -254,6 +256,7 @@ func (h *BindHandle) DropInvalidBindRecord() {
 
 		if time.Since(invalidBindRecord.droppedTime) > 6*time.Second {
 			delete(invalidBindRecordMap, key)
+			invalidBindRecord.bindRecord.updateMetrics(metrics.ScopeGlobal, false)
 		}
 	}
 	h.invalidBindRecordMap.Store(invalidBindRecordMap)
@@ -275,6 +278,7 @@ func (h *BindHandle) AddDropInvalidBindTask(invalidBindRecord *BindRecord) {
 		bindRecord: invalidBindRecord,
 	}
 	h.invalidBindRecordMap.Store(newMap)
+	invalidBindRecord.updateMetrics(metrics.ScopeGlobal, true)
 }
 
 // Size return the size of bind info cache.
@@ -320,8 +324,9 @@ func newBindMetaWithoutAst(record *BindRecord) (hash string, meta *BindMeta) {
 // removed from the cache after this operation.
 func (h *BindHandle) appendBindMeta(hash string, meta *BindMeta) {
 	newCache := h.bindInfo.Value.Load().(cache).copy()
-	newCache.removeStaleBindMetas(hash, meta)
+	newCache.removeStaleBindMetas(hash, meta, metrics.ScopeGlobal)
 	newCache[hash] = append(newCache[hash], meta)
+	meta.updateMetrics(metrics.ScopeGlobal, true)
 	h.bindInfo.Value.Store(newCache)
 }
 
@@ -334,18 +339,19 @@ func (h *BindHandle) removeBindMeta(hash string, meta *BindMeta) {
 		h.bindInfo.Unlock()
 	}()
 
-	newCache.removeDeletedBindMeta(hash, meta)
+	newCache.removeDeletedBindMeta(hash, meta, metrics.ScopeGlobal)
 }
 
 // removeDeletedBindMeta removes all the BindMeta which originSQL and db are the same with the parameter's meta.
-func (c cache) removeDeletedBindMeta(hash string, meta *BindMeta) {
+func (c cache) removeDeletedBindMeta(hash string, meta *BindMeta, scope string) {
 	metas, ok := c[hash]
 	if !ok {
 		return
 	}
 
 	for i := len(metas) - 1; i >= 0; i-- {
-		if meta.isSame(meta) {
+		if metas[i].isSame(meta) {
+			metas[i].updateMetrics(scope, false)
 			metas = append(metas[:i], metas[i+1:]...)
 			if len(metas) == 0 {
 				delete(c, hash)
@@ -356,15 +362,15 @@ func (c cache) removeDeletedBindMeta(hash string, meta *BindMeta) {
 }
 
 // removeStaleBindMetas removes all the stale BindMeta in the cache.
-func (c cache) removeStaleBindMetas(hash string, meta *BindMeta) {
+func (c cache) removeStaleBindMetas(hash string, meta *BindMeta, scope string) {
 	metas, ok := c[hash]
 	if !ok {
 		return
 	}
 
-	// remove stale bindMetas.
 	for i := len(metas) - 1; i >= 0; i-- {
 		if metas[i].isStale(meta) {
+			metas[i].updateMetrics(scope, false)
 			metas = append(metas[:i], metas[i+1:]...)
 			if len(metas) == 0 {
 				delete(c, hash)

bindinfo/session_handle.go

@@ -18,6 +18,7 @@ import (
 
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/mysql"
+	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/types"
 )
 
@@ -38,8 +39,9 @@ func NewSessionBindHandle(parser *parser.Parser) *SessionHandle {
 // removed from the cache after this operation.
 func (h *SessionHandle) appendBindMeta(hash string, meta *BindMeta) {
 	// Make sure there is only one goroutine writes the cache.
-	h.ch.removeStaleBindMetas(hash, meta)
+	h.ch.removeStaleBindMetas(hash, meta, metrics.ScopeSession)
 	h.ch[hash] = append(h.ch[hash], meta)
+	meta.updateMetrics(metrics.ScopeSession, true)
 }
 
 func (h *SessionHandle) newBindMeta(record *BindRecord) (hash string, meta *BindMeta, err error) {
@@ -74,7 +76,7 @@ func (h *SessionHandle) DropBindRecord(record *BindRecord) {
 	meta := &BindMeta{BindRecord: record}
 	meta.Status = deleted
 	hash := parser.DigestHash(record.OriginalSQL)
-	h.ch.removeDeletedBindMeta(hash, meta)
+	h.ch.removeDeletedBindMeta(hash, meta, metrics.ScopeSession)
 	h.appendBindMeta(hash, meta)
 }
 
@@ -100,6 +102,15 @@ func (h *SessionHandle) GetAllBindRecord() (bindRecords []*BindMeta) {
 	return bindRecords
 }
 
+// Close closes the session handle.
+func (h *SessionHandle) Close() {
+	for _, bindRecords := range h.ch {
+		for _, bindRecord := range bindRecords {
+			bindRecord.updateMetrics(metrics.ScopeSession, false)
+		}
+	}
+}
+
 // sessionBindInfoKeyType is a dummy type to avoid naming collision in context.
 type sessionBindInfoKeyType int
 

executor/compiler.go

@@ -404,6 +404,7 @@ func addHintForSelect(hash, normdOrigSQL string, ctx sessionctx.Context, stmt as
 			return stmt
 		}
 		if bindRecord.Status == bindinfo.Using {
+			metrics.BindUsageCounter.WithLabelValues(metrics.ScopeSession).Inc()
 			return bindinfo.BindHint(stmt, bindRecord.Ast)
 		}
 	}
@@ -413,6 +414,7 @@ func addHintForSelect(hash, normdOrigSQL string, ctx sessionctx.Context, stmt as
 		bindRecord = globalHandle.GetBindRecord(hash, normdOrigSQL, "")
 	}
 	if bindRecord != nil {
+		metrics.BindUsageCounter.WithLabelValues(metrics.ScopeGlobal).Inc()
 		return bindinfo.BindHint(stmt, bindRecord.Ast)
 	}
 	return stmt

metrics/bindinfo.go

@@ -0,0 +1,43 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metrics
+
+import "github.com/prometheus/client_golang/prometheus"
+
+// bindinfo metrics.
+var (
+	BindUsageCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "tidb",
+			Subsystem: "bindinfo",
+			Name:      "bind_usage_counter",
+			Help:      "Counter of query using sql bind",
+		}, []string{LableScope})
+
+	BindTotalGauge = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "bindinfo",
+			Name:      "bind_total_gauge",
+			Help:      "Total number of sql bind",
+		}, []string{LableScope, LblType})
+
+	BindMemoryUsage = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "bindinfo",
+			Name:      "bind_memory_usage",
+			Help:      "Memory usage of sql bind",
+		}, []string{LableScope, LblType})
+)

metrics/metrics.go

@@ -41,6 +41,10 @@ const (
 
 	opSucc   = "ok"
 	opFailed = "err"
+
+	LableScope   = "scope"
+	ScopeGlobal  = "global"
+	ScopeSession = "session"
 )
 
 // RetLabel returns "ok" when err == nil and "err" when err != nil.
@@ -58,6 +62,9 @@ func RegisterMetrics() {
 	prometheus.MustRegister(AutoAnalyzeHistogram)
 	prometheus.MustRegister(AutoIDHistogram)
 	prometheus.MustRegister(BatchAddIdxHistogram)
+	prometheus.MustRegister(BindUsageCounter)
+	prometheus.MustRegister(BindTotalGauge)
+	prometheus.MustRegister(BindMemoryUsage)
 	prometheus.MustRegister(CampaignOwnerCounter)
 	prometheus.MustRegister(ConnGauge)
 	prometheus.MustRegister(PreparedStmtGauge)

session/session.go

@@ -1364,6 +1364,10 @@ func (s *session) Close() {
 	if s.statsCollector != nil {
 		s.statsCollector.Delete()
 	}
+	bindValue := s.Value(bindinfo.SessionBindInfoKeyType)
+	if bindValue != nil {
+		bindValue.(*bindinfo.SessionHandle).Close()
+	}
 	ctx := context.TODO()
 	s.RollbackTxn(ctx)
 	if s.sessionVars != nil {