storage,localtestcluster: disable randomized separated intents

Separated intents are fully baked in now, so this randomization makes
less sense. We continue to randomize in some tests, such as
TestMVCCHistories, so some coverage is retained.

The randomization caused nondeterminism during refactors of testContext
(where it was then affecting tests that were written with separated
intents hard-coded to "on") and so there was an immediate reason to
remove it.

Release note: None

pkg/storage/open.go

@@ -12,12 +12,10 @@ package storage
 
 import (
 	"context"
-	"math/rand"
 
 	"github.com/cockroachdb/cockroach/pkg/base"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
-	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/pebble"
 	"github.com/cockroachdb/pebble/vfs"
 )
@@ -51,16 +49,11 @@ var MustExist ConfigOption = func(cfg *engineConfig) error {
 }
 
 // ForTesting configures the engine for use in testing. It may randomize some
-// config options to improve test coverage
+// config options to improve test coverage.
 var ForTesting ConfigOption = func(cfg *engineConfig) error {
 	if cfg.Settings == nil {
 		cfg.Settings = cluster.MakeTestingClusterSettings()
 	}
-	disableSeparatedIntents := rand.Intn(2) == 0
-	log.Infof(context.Background(),
-		"engine creation is randomly setting disableSeparatedIntents: %t",
-		disableSeparatedIntents)
-	cfg.DisableSeparatedIntents = disableSeparatedIntents
 	return nil
 }
 

pkg/testutils/localtestcluster/local_test_cluster.go

@@ -133,17 +133,13 @@ func (ltc *LocalTestCluster) Start(t testing.TB, baseCtx *base.Config, initFacto
 	clusterID := &cfg.RPCContext.ClusterID
 	server := rpc.NewServer(cfg.RPCContext) // never started
 	ltc.Gossip = gossip.New(ambient, clusterID, nc, cfg.RPCContext, server, ltc.stopper, metric.NewRegistry(), roachpb.Locality{}, zonepb.DefaultZoneConfigRef())
-	disableSeparatedIntents := !cfg.Settings.Version.ActiveVersionOrEmpty(
-		context.Background()).IsActive(clusterversion.PostSeparatedIntentsMigration)
-	log.Infof(context.Background(), "engine creation is randomly setting disableSeparatedIntents: %t",
-		disableSeparatedIntents)
 	var err error
 	ltc.Eng, err = storage.Open(
 		ambient.AnnotateCtx(context.Background()),
 		storage.InMemory(),
 		storage.CacheSize(0),
 		storage.MaxSize(50<<20 /* 50 MiB */),
-		storage.SetSeparatedIntents(disableSeparatedIntents))
+	)
 	if err != nil {
 		t.Fatal(err)
 	}