Simplify vtgate resolver

go/vt/discovery/tablet_stats_cache.go

@@ -17,7 +17,6 @@ limitations under the License.
 package discovery
 
 import (
-	"math"
 	"sync"
 
 	"golang.org/x/net/context"
@@ -27,7 +26,6 @@ import (
 	"vitess.io/vitess/go/vt/srvtopo"
 	"vitess.io/vitess/go/vt/topo"
 	"vitess.io/vitess/go/vt/topo/topoproto"
-	"vitess.io/vitess/go/vt/topotools"
 )
 
 // TabletStatsCache is a HealthCheckStatsListener that keeps both the
@@ -47,8 +45,6 @@ type TabletStatsCache struct {
 	cell string
 	// ts is the topo server in use.
 	ts *topo.Server
-	// aggregatesChan is used to send notifications to listeners.
-	aggregatesChan chan []*srvtopo.TargetStatsEntry
 	// mu protects the following fields. It does not protect individual
 	// entries in the entries map.
 	mu sync.RWMutex
@@ -70,8 +66,6 @@ type tabletStatsCacheEntry struct {
 	all map[string]*TabletStats
 	// healthy only has the healthy ones.
 	healthy []*TabletStats
-	// aggregates has the per-alias aggregates.
-	aggregates map[string]*querypb.AggregateStats
 }
 
 func (e *tabletStatsCacheEntry) updateHealthyMapForMaster(ts *TabletStats) {
@@ -131,12 +125,11 @@ func NewTabletStatsCacheDoNotSetListener(ts *topo.Server, cell string) *TabletSt
 
 func newTabletStatsCache(hc HealthCheck, ts *topo.Server, cell string, setListener bool) *TabletStatsCache {
 	tc := &TabletStatsCache{
-		cell:           cell,
-		ts:             ts,
-		aggregatesChan: make(chan []*srvtopo.TargetStatsEntry, 100),
-		entries:        make(map[string]map[string]map[topodatapb.TabletType]*tabletStatsCacheEntry),
-		tsm:            srvtopo.NewTargetStatsMultiplexer(),
-		cellAliases:    make(map[string]string),
+		cell:        cell,
+		ts:          ts,
+		entries:     make(map[string]map[string]map[topodatapb.TabletType]*tabletStatsCacheEntry),
+		tsm:         srvtopo.NewTargetStatsMultiplexer(),
+		cellAliases: make(map[string]string),
 	}
 
 	if setListener {
@@ -188,8 +181,7 @@ func (tc *TabletStatsCache) getOrCreateEntry(target *querypb.Target) *tabletStat
 	e, ok := t[target.TabletType]
 	if !ok {
 		e = &tabletStatsCacheEntry{
-			all:        make(map[string]*TabletStats),
-			aggregates: make(map[string]*querypb.AggregateStats),
+			all: make(map[string]*TabletStats),
 		}
 		t[target.TabletType] = e
 	}
@@ -258,9 +250,6 @@ func (tc *TabletStatsCache) StatsUpdate(ts *TabletStats) {
 		// The healthy list is different for TabletType_MASTER: we
 		// only keep the most recent one.
 		e.updateHealthyMapForMaster(ts)
-		for _, s := range e.all {
-			allArray = append(allArray, s)
-		}
 	} else {
 		// For non-master, if it is a trivial update,
 		// we just skip everything else. We don't even update the
@@ -276,45 +265,6 @@ func (tc *TabletStatsCache) StatsUpdate(ts *TabletStats) {
 		}
 		e.healthy = FilterByReplicationLag(allArray)
 	}
-
-	tc.updateAggregateMap(ts.Target.Keyspace, ts.Target.Shard, ts.Target.TabletType, e, allArray)
-}
-
-// makeAggregateMap takes a list of TabletStats and builds a per-alias
-// AggregateStats map.
-func (tc *TabletStatsCache) makeAggregateMap(stats []*TabletStats) map[string]*querypb.AggregateStats {
-	result := make(map[string]*querypb.AggregateStats)
-	for _, ts := range stats {
-		alias := tc.getAliasByCell(ts.Tablet.Alias.Cell)
-		agg, ok := result[alias]
-		if !ok {
-			agg = &querypb.AggregateStats{
-				SecondsBehindMasterMin: math.MaxUint32,
-			}
-			result[alias] = agg
-		}
-
-		if ts.Serving && ts.LastError == nil {
-			agg.HealthyTabletCount++
-			if ts.Stats.SecondsBehindMaster < agg.SecondsBehindMasterMin {
-				agg.SecondsBehindMasterMin = ts.Stats.SecondsBehindMaster
-			}
-			if ts.Stats.SecondsBehindMaster > agg.SecondsBehindMasterMax {
-				agg.SecondsBehindMasterMax = ts.Stats.SecondsBehindMaster
-			}
-		} else {
-			agg.UnhealthyTabletCount++
-		}
-	}
-	return result
-}
-
-// updateAggregateMap will update the aggregate map for the
-// tabletStatsCacheEntry. It may broadcast the changes too if we have listeners.
-// e.mu needs to be locked.
-func (tc *TabletStatsCache) updateAggregateMap(keyspace, shard string, tabletType topodatapb.TabletType, e *tabletStatsCacheEntry, stats []*TabletStats) {
-	// Save the new value
-	e.aggregates = tc.makeAggregateMap(stats)
 }
 
 // GetTabletStats returns the full list of available targets.
@@ -361,53 +311,5 @@ func (tc *TabletStatsCache) ResetForTesting() {
 	tc.entries = make(map[string]map[string]map[topodatapb.TabletType]*tabletStatsCacheEntry)
 }
 
-// GetAggregateStats is part of the TargetStatsListener interface.
-func (tc *TabletStatsCache) GetAggregateStats(target *querypb.Target) (*querypb.AggregateStats, error) {
-	e := tc.getEntry(target.Keyspace, target.Shard, target.TabletType)
-	if e == nil {
-		return nil, topo.NewError(topo.NoNode, topotools.TargetIdent(target))
-	}
-
-	e.mu.RLock()
-	defer e.mu.RUnlock()
-	if target.TabletType == topodatapb.TabletType_MASTER {
-		if len(e.aggregates) == 0 {
-			return nil, topo.NewError(topo.NoNode, topotools.TargetIdent(target))
-		}
-		for _, agg := range e.aggregates {
-			return agg, nil
-		}
-	}
-	targetAlias := tc.getAliasByCell(target.Cell)
-	agg, ok := e.aggregates[targetAlias]
-	if !ok {
-		return nil, topo.NewError(topo.NoNode, topotools.TargetIdent(target))
-	}
-	return agg, nil
-}
-
-// GetMasterCell is part of the TargetStatsListener interface.
-func (tc *TabletStatsCache) GetMasterCell(keyspace, shard string) (cell string, err error) {
-	e := tc.getEntry(keyspace, shard, topodatapb.TabletType_MASTER)
-	if e == nil {
-		return "", topo.NewError(topo.NoNode, topotools.TargetIdent(&querypb.Target{
-			Keyspace:   keyspace,
-			Shard:      shard,
-			TabletType: topodatapb.TabletType_MASTER,
-		}))
-	}
-
-	e.mu.RLock()
-	defer e.mu.RUnlock()
-	for cell := range e.aggregates {
-		return cell, nil
-	}
-	return "", topo.NewError(topo.NoNode, topotools.TargetIdent(&querypb.Target{
-		Keyspace:   keyspace,
-		Shard:      shard,
-		TabletType: topodatapb.TabletType_MASTER,
-	}))
-}
-
 // Compile-time interface check.
 var _ HealthCheckStatsListener = (*TabletStatsCache)(nil)