Throttler: cleaning up legacy remote MySQL connection logic

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

@@ -13,8 +13,6 @@ package config
 // MySQLClusterConfigurationSettings has the settings for a specific MySQL cluster. It derives its information
 // from MySQLConfigurationSettings
 type MySQLClusterConfigurationSettings struct {
-	User                 string   // override MySQLConfigurationSettings's, or leave empty to inherit those settings
-	Password             string   // override MySQLConfigurationSettings's, or leave empty to inherit those settings
 	MetricQuery          string   // override MySQLConfigurationSettings's, or leave empty to inherit those settings
 	CacheMillis          int      // override MySQLConfigurationSettings's, or leave empty to inherit those settings
 	ThrottleThreshold    float64  // override MySQLConfigurationSettings's, or leave empty to inherit those settings
@@ -33,8 +31,6 @@ func (settings *MySQLClusterConfigurationSettings) postReadAdjustments() error {
 
 // MySQLConfigurationSettings has the general configuration for all MySQL clusters
 type MySQLConfigurationSettings struct {
-	User                 string
-	Password             string
 	MetricQuery          string
 	CacheMillis          int // optional, if defined then probe result will be cached, and future probes may use cached value
 	ThrottleThreshold    float64
@@ -59,12 +55,6 @@ func (settings *MySQLConfigurationSettings) postReadAdjustments() error {
 		if err := clusterSettings.postReadAdjustments(); err != nil {
 			return err
 		}
-		if clusterSettings.User == "" {
-			clusterSettings.User = settings.User
-		}
-		if clusterSettings.Password == "" {
-			clusterSettings.Password = settings.Password
-		}
 		if clusterSettings.MetricQuery == "" {
 			clusterSettings.MetricQuery = settings.MetricQuery
 		}

go/vt/vttablet/tabletserver/throttle/mysql/mysql_throttle_metric.go

@@ -13,8 +13,6 @@ import (
 
 	"github.com/patrickmn/go-cache"
 	metrics "github.com/rcrowley/go-metrics"
-
-	"vitess.io/vitess/go/vt/orchestrator/external/golib/sqlutils"
 )
 
 // MetricsQueryType indicates the type of metrics query on MySQL backend. See following.
@@ -118,44 +116,6 @@ func ReadThrottleMetric(probe *Probe, clusterName string, overrideGetMetricFunc
 		}()
 	}(mySQLThrottleMetric, started)
 
-	if overrideGetMetricFunc != nil {
-		mySQLThrottleMetric = overrideGetMetricFunc()
-		return cacheMySQLThrottleMetric(probe, mySQLThrottleMetric)
-	}
-
-	dbURI := probe.GetDBUri("information_schema")
-	db, fromCache, err := sqlutils.GetDB(dbURI)
-
-	if err != nil {
-		mySQLThrottleMetric.Err = err
-		return mySQLThrottleMetric
-	}
-	if !fromCache {
-		db.SetMaxOpenConns(maxPoolConnections)
-		db.SetMaxIdleConns(maxIdleConnections)
-	}
-	metricsQueryType := GetMetricsQueryType(probe.MetricQuery)
-	switch metricsQueryType {
-	case MetricsQueryTypeSelect:
-		mySQLThrottleMetric.Err = db.QueryRow(probe.MetricQuery).Scan(&mySQLThrottleMetric.Value)
-		return cacheMySQLThrottleMetric(probe, mySQLThrottleMetric)
-	case MetricsQueryTypeShowGlobal:
-		var variableName string // just a placeholder
-		mySQLThrottleMetric.Err = db.QueryRow(probe.MetricQuery).Scan(&variableName, &mySQLThrottleMetric.Value)
-		return cacheMySQLThrottleMetric(probe, mySQLThrottleMetric)
-	case MetricsQueryTypeDefault:
-		mySQLThrottleMetric.Err = sqlutils.QueryRowsMap(db, `show slave status`, func(m sqlutils.RowMap) error {
-			IOThreadRunning := m.GetString("Slave_IO_Running")
-			SQLThreadRunning := m.GetString("Slave_SQL_Running")
-			replicationLagSeconds := m.GetNullInt64("Seconds_Behind_Master")
-			if !replicationLagSeconds.Valid {
-				return fmt.Errorf("replication not running; Slave_IO_Running=%+v, Slave_SQL_Running=%+v", IOThreadRunning, SQLThreadRunning)
-			}
-			mySQLThrottleMetric.Value = float64(replicationLagSeconds.Int64)
-			return nil
-		})
-		return cacheMySQLThrottleMetric(probe, mySQLThrottleMetric)
-	}
-	mySQLThrottleMetric.Err = fmt.Errorf("Unsupported metrics query type: %s", probe.MetricQuery)
-	return mySQLThrottleMetric
+	mySQLThrottleMetric = overrideGetMetricFunc()
+	return cacheMySQLThrottleMetric(probe, mySQLThrottleMetric)
 }

go/vt/vttablet/tabletserver/throttle/mysql/probe.go

@@ -8,18 +8,11 @@ package mysql
 
 import (
 	"fmt"
-	"net"
 )
 
-const maxPoolConnections = 3
-const maxIdleConnections = 3
-const timeoutMillis = 1000
-
 // Probe is the minimal configuration required to connect to a MySQL server
 type Probe struct {
 	Key             InstanceKey
-	User            string
-	Password        string
 	MetricQuery     string
 	TabletHost      string
 	TabletPort      int
@@ -51,38 +44,12 @@ func NewProbe() *Probe {
 	return config
 }
 
-// DuplicateCredentials creates a new connection config with given key and with same credentials as this config
-func (p *Probe) DuplicateCredentials(key InstanceKey) *Probe {
-	config := &Probe{
-		Key:      key,
-		User:     p.User,
-		Password: p.Password,
-	}
-	return config
-}
-
-// Duplicate duplicates this probe, including credentials
-func (p *Probe) Duplicate() *Probe {
-	return p.DuplicateCredentials(p.Key)
-}
-
 // String returns a human readable string of this struct
 func (p *Probe) String() string {
-	return fmt.Sprintf("%s, user=%s", p.Key.DisplayString(), p.User)
+	return fmt.Sprintf("%s, tablet=%s:%d", p.Key.DisplayString(), p.TabletHost, p.TabletPort)
 }
 
 // Equals checks if this probe has same instance key as another
 func (p *Probe) Equals(other *Probe) bool {
 	return p.Key.Equals(&other.Key)
 }
-
-// GetDBUri returns the DB URI for the mysql server indicated by this probe
-func (p *Probe) GetDBUri(databaseName string) string {
-	hostname := p.Key.Hostname
-	var ip = net.ParseIP(hostname)
-	if (ip != nil) && (ip.To4() == nil) {
-		// Wrap IPv6 literals in square brackets
-		hostname = fmt.Sprintf("[%s]", hostname)
-	}
-	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?interpolateParams=true&charset=utf8mb4,utf8,latin1&timeout=%dms", p.User, p.Password, hostname, p.Key.Port, databaseName, timeoutMillis)
-}

go/vt/vttablet/tabletserver/throttle/mysql/probe_test.go

@@ -16,32 +16,4 @@ func TestNewProbe(t *testing.T) {
 	c := NewProbe()
 	assert.Equal(t, "", c.Key.Hostname)
 	assert.Equal(t, 0, c.Key.Port)
-	assert.Equal(t, "", c.User)
-	assert.Equal(t, "", c.Password)
-}
-
-func TestDuplicateCredentials(t *testing.T) {
-	c := NewProbe()
-	c.Key = InstanceKey{Hostname: "myhost", Port: 3306}
-	c.User = "gromit"
-	c.Password = "penguin"
-
-	dup := c.DuplicateCredentials(InstanceKey{Hostname: "otherhost", Port: 3310})
-	assert.Equal(t, "otherhost", dup.Key.Hostname)
-	assert.Equal(t, 3310, dup.Key.Port)
-	assert.Equal(t, "gromit", dup.User)
-	assert.Equal(t, "penguin", dup.Password)
-}
-
-func TestDuplicate(t *testing.T) {
-	c := NewProbe()
-	c.Key = InstanceKey{Hostname: "myhost", Port: 3306}
-	c.User = "gromit"
-	c.Password = "penguin"
-
-	dup := c.Duplicate()
-	assert.Equal(t, "myhost", dup.Key.Hostname)
-	assert.Equal(t, 3306, dup.Key.Port)
-	assert.Equal(t, "gromit", dup.User)
-	assert.Equal(t, "penguin", dup.Password)
 }