server: use a single setting for tenant waiting

We can use a zero-wait time to indicate no waiting, saving a cluster
setting.

Epic: none

Release note: None

pkg/multitenant/tenant_config.go

@@ -43,22 +43,12 @@ var VerifyTenantService = settings.RegisterBoolSetting(
 	settings.WithName(DefaultClusterSelectSettingName+".check_service.enabled"),
 )
 
-// WaitForClusterStart, if enabled, instructs the tenant controller to
-// wait up to WaitForClusterStartTimeout for the defuault virtual
-// cluster to have an active SQL server.
-var WaitForClusterStart = settings.RegisterBoolSetting(
-	settings.SystemOnly,
-	"server.controller.mux_virtual_cluster_wait.enabled",
-	"wait up to server.controller_mux_virtual_cluster_wait.timeout for the default virtual cluster to become available for SQL connections",
-	false,
-)
-
-// WaitForClusterStartTimeout is the amoutn of time the the tenant
+// WaitForClusterStartTimeout is the amount of time the tenant
 // controller will wait for the default virtual cluster to have an
-// active SQL server, if WaitForClusterStart is true.
+// active SQL server.
 var WaitForClusterStartTimeout = settings.RegisterDurationSetting(
 	settings.SystemOnly,
 	"server.controller.mux_virtual_cluster_wait.timeout",
-	"amount of time to wait for a default virtual cluster to become available when serving SQL connections",
+	"amount of time to wait for a default virtual cluster to become available when serving SQL connections (0 to disable)",
 	10*time.Second,
 )

pkg/server/server_controller_sql.go

@@ -110,7 +110,7 @@ func (c *serverController) shouldWaitForTenantServer(name roachpb.TenantName) bo
 		return false
 	}
 
-	return multitenant.WaitForClusterStart.Get(&c.st.SV)
+	return multitenant.WaitForClusterStartTimeout.Get(&c.st.SV) > 0
 }
 
 func (c *serverController) waitForTenantServer(

pkg/server/server_controller_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/testutils"
 	"github.com/cockroachdb/cockroach/pkg/testutils/serverutils"
 	"github.com/cockroachdb/cockroach/pkg/testutils/sqlutils"
+	"github.com/cockroachdb/cockroach/pkg/util"
 	"github.com/cockroachdb/cockroach/pkg/util/leaktest"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/errors"
@@ -138,7 +139,9 @@ func TestServerControllerWaitForDefaultCluster(t *testing.T) {
 	defer s.Stopper().Stop(ctx)
 
 	sqlRunner := sqlutils.MakeSQLRunner(db)
-	sqlRunner.Exec(t, "SET CLUSTER SETTING server.controller.mux_virtual_cluster_wait.enabled = true")
+	if util.RaceEnabled {
+		sqlRunner.Exec(t, "SET CLUSTER SETTING server.controller.mux_virtual_cluster_wait.timeout = '1m'")
+	}
 
 	tryConnect := func() error {
 		conn, err := s.SystemLayer().SQLConnE(serverutils.DBName("cluster:hello"))