cache: use the legacy LRU cache by default

Signed-off-by: Vicent Marti <[email protected]>

go/cache/cache.go

@@ -27,9 +27,9 @@ package cache
 // Regardless of the default value used here, the user can always override Vitess' configuration to
 // force a specific cache type (e.g. when passing a value in ENTRIES to vtgate, the service will use
 // a LRU cache).
-const DefaultCacheSize = SizeInBytes(64 * 1024 * 1024)
+const DefaultCacheSize = SizeInEntries(5000)
 
-// const DefaultCacheSize = SizeInEntries(10000)
+// const DefaultCacheSize = SizeInBytes(64 * 1024 * 1024)
 
 // Cache is a generic interface type for a data structure that keeps recently used
 // objects in memory and evicts them when it becomes full.

go/vt/vttablet/tabletserver/query_engine_test.go

@@ -26,6 +26,7 @@ import (
 	"testing"
 	"time"
 
+	"vitess.io/vitess/go/cache"
 	"vitess.io/vitess/go/streamlog"
 
 	"vitess.io/vitess/go/mysql/fakesqldb"
@@ -166,7 +167,11 @@ func TestQueryPlanCache(t *testing.T) {
 
 	ctx := context.Background()
 	logStats := tabletenv.NewLogStats(ctx, "GetPlanStats")
-	qe.SetQueryPlanCacheCap(1024)
+	if cache.DefaultCacheSize.Bytes() != 0 {
+		qe.SetQueryPlanCacheCap(1024)
+	} else {
+		qe.SetQueryPlanCacheCap(1)
+	}
 	firstPlan, err := qe.GetPlan(ctx, logStats, firstQuery, false, false /* inReservedConn */)
 	if err != nil {
 		t.Fatal(err)

go/vt/vttablet/tabletserver/tabletenv/config_test.go

@@ -119,7 +119,6 @@ hotRowProtection:
   maxGlobalQueueSize: 1000
   maxQueueSize: 20
   mode: disable
-lfuQueryCacheSizeBytes: 67108864
 messagePostponeParallelism: 4
 olapReadPool:
   idleTimeoutSeconds: 1800
@@ -132,6 +131,7 @@ oltpReadPool:
   idleTimeoutSeconds: 1800
   maxWaiters: 5000
   size: 16
+queryCacheSize: 5000
 replicationTracker:
   heartbeatIntervalSeconds: 0.25
   mode: disable