statscache: update config and metrics for stats cache (#45581)

close #45367
pingcap · Jul 26, 2023 · 93a880a · 93a880a
1 parent 7e18f79
commit 93a880a
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Showing 20 changed files with 1,528 additions and 2,117 deletions.
diff --git a/domain/domain_sysvars.go b/domain/domain_sysvars.go
@@ -31,7 +31,8 @@ import (
 // because the domain is not available. Instead a noop func is specified,
 // which is overwritten here.
 func (do *Domain) initDomainSysVars() {
-	variable.SetStatsCacheCapacity.Store(do.setStatsCacheCapacity)
+	setStatsCacheCapacityFunc := do.setStatsCacheCapacity
+	variable.SetStatsCacheCapacity.Store(&setStatsCacheCapacityFunc)
 	pdClientDynamicOptionFunc := do.setPDClientDynamicOption
 	variable.SetPDClientDynamicOption.Store(&pdClientDynamicOptionFunc)
 

diff --git a/metrics/grafana/tidb.json b/metrics/grafana/tidb.json
@@ -14768,7 +14768,7 @@
           "dashLength": 10,
           "dashes": false,
           "datasource": "${DS_TEST-CLUSTER}",
-          "description": "TiDB managing stats cache by lru",
+          "description": "TiDB managing stats cache",
           "editable": true,
           "error": false,
           "fieldConfig": {
@@ -14819,7 +14819,7 @@
           "targets": [
             {
               "exemplar": true,
-              "expr": "tidb_statistics_stats_cache_lru_val{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\", type=\"track\"}",
+              "expr": "tidb_statistics_stats_cache_val{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\", type=\"track\"}",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -14828,7 +14828,7 @@
             },
             {
               "exemplar": true,
-              "expr": "tidb_statistics_stats_cache_lru_val{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\", type=\"capacity\"}",
+              "expr": "tidb_statistics_stats_cache_val{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\", type=\"capacity\"}",
               "hide": true,
               "interval": "",
               "legendFormat": "capacity--{{instance}}",
@@ -14839,7 +14839,7 @@
           "timeFrom": null,
           "timeRegions": [],
           "timeShift": null,
-          "title": "Stats Cache LRU Cost",
+          "title": "Stats Cache Cost",
           "tooltip": {
             "msResolution": true,
             "shared": true,
@@ -14883,7 +14883,7 @@
           "dashLength": 10,
           "dashes": false,
           "datasource": "${DS_TEST-CLUSTER}",
-          "description": "TiDB managing stats cache by lru",
+          "description": "TiDB managing stats cache",
           "fieldConfig": {
             "defaults": {},
             "overrides": []
@@ -14928,7 +14928,7 @@
           "targets": [
             {
               "exemplar": true,
-              "expr": "sum(rate(tidb_statistics_stats_cache_lru_op{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\"}[1m])) by (type)",
+              "expr": "sum(rate(tidb_statistics_stats_cache_op{k8s_cluster=\"$k8s_cluster\", tidb_cluster=\"$tidb_cluster\"}[1m])) by (type)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 2,
@@ -14941,7 +14941,7 @@
           "timeFrom": null,
           "timeRegions": [],
           "timeShift": null,
-          "title": "Stats Cache LRU OPS",
+          "title": "Stats Cache OPS",
           "tooltip": {
             "shared": true,
             "sort": 0,

diff --git a/metrics/metrics.go b/metrics/metrics.go
@@ -232,8 +232,8 @@ func RegisterMetrics() {
 	prometheus.MustRegister(PessimisticDMLDurationByAttempt)
 	prometheus.MustRegister(ResourceGroupQueryTotalCounter)
 	prometheus.MustRegister(MemoryUsage)
-	prometheus.MustRegister(StatsCacheLRUCounter)
-	prometheus.MustRegister(StatsCacheLRUGauge)
+	prometheus.MustRegister(StatsCacheCounter)
+	prometheus.MustRegister(StatsCacheGauge)
 	prometheus.MustRegister(StatsHealthyGauge)
 	prometheus.MustRegister(TxnStatusEnteringCounter)
 	prometheus.MustRegister(TxnDurationHistogram)

diff --git a/metrics/stats.go b/metrics/stats.go
@@ -33,8 +33,8 @@ var (
 	SyncLoadTimeoutCounter     prometheus.Counter
 	SyncLoadHistogram          prometheus.Histogram
 	ReadStatsHistogram         prometheus.Histogram
-	StatsCacheLRUCounter       *prometheus.CounterVec
-	StatsCacheLRUGauge         *prometheus.GaugeVec
+	StatsCacheCounter          *prometheus.CounterVec
+	StatsCacheGauge            *prometheus.GaugeVec
 	StatsHealthyGauge          *prometheus.GaugeVec
 
 	HistoricalStatsCounter        *prometheus.CounterVec
@@ -153,19 +153,19 @@ func InitStatsMetrics() {
 			Buckets:   prometheus.ExponentialBuckets(1, 2, 22), // 1ms ~ 1h
 		})
 
-	StatsCacheLRUCounter = NewCounterVec(
+	StatsCacheCounter = NewCounterVec(
 		prometheus.CounterOpts{
 			Namespace: "tidb",
 			Subsystem: "statistics",
-			Name:      "stats_cache_lru_op",
-			Help:      "Counter of lru for statsCache operation",
+			Name:      "stats_cache_op",
+			Help:      "Counter for statsCache operation",
 		}, []string{LblType})
 
-	StatsCacheLRUGauge = NewGaugeVec(prometheus.GaugeOpts{
+	StatsCacheGauge = NewGaugeVec(prometheus.GaugeOpts{
 		Namespace: "tidb",
 		Subsystem: "statistics",
-		Name:      "stats_cache_lru_val",
-		Help:      "gauge of stats cache lru value",
+		Name:      "stats_cache_val",
+		Help:      "gauge of stats cache value",
 	}, []string{LblType})
 
 	StatsHealthyGauge = NewGaugeVec(prometheus.GaugeOpts{

diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
@@ -1088,7 +1088,8 @@ var defaultSysVars = []*SysVar{
 			oldv := StatsCacheMemQuota.Load()
 			if v != oldv {
 				StatsCacheMemQuota.Store(v)
-				SetStatsCacheCapacity.Load().(func(int64))(v)
+				SetStatsCacheCapacityFunc := SetStatsCacheCapacity.Load()
+				(*SetStatsCacheCapacityFunc)(v)
 			}
 			return nil
 		},

diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
@@ -1490,7 +1490,7 @@ var (
 	// GetMemQuotaAnalyze is the func registered by global/subglobal tracker to get memory quota.
 	GetMemQuotaAnalyze func() int64 = nil
 	// SetStatsCacheCapacity is the func registered by domain to set statsCache memory quota.
-	SetStatsCacheCapacity atomic.Value
+	SetStatsCacheCapacity atomic.Pointer[func(int64)]
 	// SetPDClientDynamicOption is the func registered by domain
 	SetPDClientDynamicOption atomic.Pointer[func(string, string)]
 	// SwitchMDL is the func registered by DDL to switch MDL.

diff --git a/statistics/handle/cache/internal/lfu/BUILD.bazel b/statistics/handle/cache/internal/lfu/BUILD.bazel
@@ -14,6 +14,7 @@ go_library(
         "//statistics/handle/cache/internal",
         "//statistics/handle/cache/internal/metrics",
         "//util/intest",
+        "//util/mathutil",
         "//util/memory",
         "@com_github_dgraph_io_ristretto//:ristretto",
         "@org_golang_x_exp//maps",

diff --git a/statistics/handle/cache/internal/lfu/lfu_cache.go b/statistics/handle/cache/internal/lfu/lfu_cache.go
@@ -22,6 +22,7 @@ import (
 	"github.com/pingcap/tidb/statistics/handle/cache/internal"
 	"github.com/pingcap/tidb/statistics/handle/cache/internal/metrics"
 	"github.com/pingcap/tidb/util/intest"
+	"github.com/pingcap/tidb/util/mathutil"
 	"github.com/pingcap/tidb/util/memory"
 )
 
@@ -47,8 +48,9 @@ func NewLFU(totalMemCost int64) (*LFU, error) {
 	if intest.InTest {
 		bufferItems = 1
 	}
+
 	cache, err := ristretto.NewCache(&ristretto.Config{
-		NumCounters:        1024 * 1024 * 1024, // TODO(hawkingrei): make it configurable for NumCounters and MaxCost
+		NumCounters:        mathutil.Max(totalMemCost/128*2, 10), // assume the cost per table stats is 128
 		MaxCost:            totalMemCost,
 		BufferItems:        bufferItems,
 		OnEvict:            result.onEvict,

diff --git a/statistics/handle/cache/internal/lru/BUILD.bazel b/statistics/handle/cache/internal/lru/BUILD.bazel