throttler uses new SelfMetric implementations. Discarding MySQLMetric…

…ConfigurationSettings. Discarding Throttler.metricsQuery

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>

go/vt/vttablet/tabletserver/throttle/base/metric_name.go

@@ -103,7 +103,7 @@ type AggregatedMetricName struct {
 }
 
 var (
-	KnownMetricNames = make([]MetricName, 0)
+	KnownMetricNames = make(MetricNames, 0)
 	// aggregatedMetricNames precomputes the aggregated metric names for all known metric names,
 	// mapped to their breakdowns. e.g. "self/loadavg" -> {SelfScope, LoadAvgMetricName}
 	// This means:

go/vt/vttablet/tabletserver/throttle/base/self_metric_custom_query.go

@@ -26,11 +26,24 @@ import (
 var _ SelfMetric = registerSelfMetric(&CustomQuerySelfMetric{})
 
 type CustomQuerySelfMetric struct {
-	customQuery atomic.Value
+	customQueryFuncPtr atomic.Pointer[func() string]
 }
 
-func (m *CustomQuerySelfMetric) SetQuery(query string) {
-	m.customQuery.Store(query)
+func (m *CustomQuerySelfMetric) GetQuery() string {
+	customQueryFunc := m.customQueryFuncPtr.Load()
+	if customQueryFunc == nil {
+		return ""
+	}
+	query := (*customQueryFunc)()
+	return query
+}
+
+func (m *CustomQuerySelfMetric) SetQueryFunc(f func() string) {
+	if f == nil {
+		m.customQueryFuncPtr.Store(nil)
+		return
+	}
+	m.customQueryFuncPtr.Store(&f)
 }
 
 func (m *CustomQuerySelfMetric) Name() MetricName {
@@ -50,9 +63,5 @@ func (m *CustomQuerySelfMetric) RequiresConn() bool {
 }
 
 func (m *CustomQuerySelfMetric) Read(ctx context.Context, conn *connpool.Conn) *ThrottleMetric {
-	query := ""
-	if val := m.customQuery.Load(); val != nil {
-		query = val.(string)
-	}
-	return ReadSelfMySQLThrottleMetric(ctx, conn, query)
+	return ReadSelfMySQLThrottleMetric(ctx, conn, m.GetQuery())
 }

go/vt/vttablet/tabletserver/throttle/base/self_metric_default.go

@@ -16,10 +16,16 @@ limitations under the License.
 
 package base
 
+import (
+	"context"
+	"fmt"
+
+	"vitess.io/vitess/go/vt/vttablet/tabletserver/connpool"
+)
+
 var _ SelfMetric = registerSelfMetric(&DefaultSelfMetric{})
 
 type DefaultSelfMetric struct {
-	LagSelfMetric
 }
 
 func (m *DefaultSelfMetric) Name() MetricName {
@@ -29,3 +35,17 @@ func (m *DefaultSelfMetric) Name() MetricName {
 func (m *DefaultSelfMetric) DefaultScope() Scope {
 	return SelfScope
 }
+
+func (m *DefaultSelfMetric) DefaultThreshold() float64 {
+	return 0
+}
+
+func (m *DefaultSelfMetric) RequiresConn() bool {
+	return false
+}
+
+func (m *DefaultSelfMetric) Read(ctx context.Context, conn *connpool.Conn) *ThrottleMetric {
+	return &ThrottleMetric{
+		Err: fmt.Errorf("unexpected direct call to DefaultSelfMetric.Read"),
+	}
+}

go/vt/vttablet/tabletserver/throttle/base/self_metric_lag.go

@@ -18,18 +18,34 @@ package base
 
 import (
 	"context"
+	"sync/atomic"
 	"time"
 
+	"vitess.io/vitess/go/constants/sidecar"
+	"vitess.io/vitess/go/vt/sqlparser"
 	"vitess.io/vitess/go/vt/vttablet/tabletserver/connpool"
 )
 
 var (
-	LagSelfMetricQuery = "show global status like 'threads_running'"
+	lagSelfMetricQueryBase = "select unix_timestamp(now(6))-max(ts/1000000000) as replication_lag from %s.heartbeat"
 )
 
 var _ SelfMetric = registerSelfMetric(&LagSelfMetric{})
 
 type LagSelfMetric struct {
+	lagSelfMetricQuery atomic.Value
+}
+
+// SetQuery is only used by unit tests to override the query.
+func (m *LagSelfMetric) SetQuery(query string) {
+	m.lagSelfMetricQuery.Store(query)
+}
+
+func (m *LagSelfMetric) GetQuery() string {
+	if query := m.lagSelfMetricQuery.Load(); query == nil {
+		m.lagSelfMetricQuery.Store(sqlparser.BuildParsedQuery(lagSelfMetricQueryBase, sidecar.GetIdentifier()).Query)
+	}
+	return m.lagSelfMetricQuery.Load().(string)
 }
 
 func (m *LagSelfMetric) Name() MetricName {
@@ -49,5 +65,5 @@ func (m *LagSelfMetric) RequiresConn() bool {
 }
 
 func (m *LagSelfMetric) Read(ctx context.Context, conn *connpool.Conn) *ThrottleMetric {
-	return ReadSelfMySQLThrottleMetric(ctx, conn, LagSelfMetricQuery)
+	return ReadSelfMySQLThrottleMetric(ctx, conn, m.GetQuery())
 }

go/vt/vttablet/tabletserver/throttle/base/self_metric_threads_running.go

@@ -19,14 +19,11 @@ package base
 import (
 	"context"
 
-	"vitess.io/vitess/go/constants/sidecar"
-	"vitess.io/vitess/go/vt/sqlparser"
 	"vitess.io/vitess/go/vt/vttablet/tabletserver/connpool"
 )
 
 var (
-	lagSelfMetricQueryBase = "select unix_timestamp(now(6))-max(ts/1000000000) as replication_lag from %s.heartbeat"
-	lagSelfMetricQuery     = sqlparser.BuildParsedQuery(lagSelfMetricQueryBase, sidecar.GetIdentifier()).Query
+	threadsRunningMetricQuery = "show global status like 'threads_running'"
 )
 
 var _ SelfMetric = registerSelfMetric(&ThreadsRunningSelfMetric{})
@@ -51,5 +48,5 @@ func (m *ThreadsRunningSelfMetric) RequiresConn() bool {
 }
 
 func (m *ThreadsRunningSelfMetric) Read(ctx context.Context, conn *connpool.Conn) *ThrottleMetric {
-	return ReadSelfMySQLThrottleMetric(ctx, conn, lagSelfMetricQuery)
+	return ReadSelfMySQLThrottleMetric(ctx, conn, threadsRunningMetricQuery)
 }

go/vt/vttablet/tabletserver/throttle/config/mysql_config.go

@@ -41,32 +41,15 @@ limitations under the License.
 
 package config
 
-import (
-	"sync/atomic"
-
-	"vitess.io/vitess/go/vt/vttablet/tabletserver/throttle/base"
-)
-
 //
 // MySQL-specific configuration
 //
 
-type MySQLMetricConfigurationSettings struct {
-	Name        base.MetricName
-	CustomQuery string
-	Threshold   atomic.Uint64
-}
-
 // MySQLConfigurationSettings has the general configuration for all MySQL clusters
 type MySQLConfigurationSettings struct {
-	CacheMillis          int      // optional, if defined then probe result will be cached, and future probes may use cached value
-	Port                 int      // Specify if different than 3306; applies to all clusters
-	IgnoreDialTCPErrors  bool     // Skip hosts where a metric cannot be retrieved due to TCP dial errors
-	IgnoreHostsCount     int      // Number of hosts that can be skipped/ignored even on error or on exceeding thresholds
-	IgnoreHostsThreshold float64  // Threshold beyond which IgnoreHostsCount applies (default: 0)
-	HTTPCheckPort        int      // port for HTTP check. -1 to disable.
-	HTTPCheckPath        string   // If non-empty, requires HTTPCheckPort
-	IgnoreHosts          []string // If non empty, substrings to indicate hosts to be ignored/skipped
-
-	Metrics map[base.MetricName]*MySQLMetricConfigurationSettings
+	CacheMillis         int      // optional, if defined then probe result will be cached, and future probes may use cached value
+	Port                int      // Specify if different than 3306; applies to all clusters
+	IgnoreDialTCPErrors bool     // Skip hosts where a metric cannot be retrieved due to TCP dial errors
+	IgnoreHostsCount    int      // Number of hosts that can be skipped/ignored even on error or on exceeding thresholds
+	IgnoreHosts         []string // If non empty, substrings to indicate hosts to be ignored/skipped
 }