sql/lease: support skipping descriptor validation lease renewals

Fixes: #95764

Previously, when renewing a lease we would fetch dependent
descriptors for cross-descriptor validation. This could
lead to perpetual transaction retries, in the schema where
there are tons of dependencies between descriptors since
lease renewals would happen in a high-priority transaction.
Additionally, this incurs additional latency for lease renewal.
To address this, this patch disables cross-validation by default for
lease renewals.

Epic: none
Release note (bug fix): Disable cross-descriptor validation on lease renewal,
which can be problematic when there are lots of descriptors with lots
of foreign key references, in which cases, the cross-reference validation could
starve schema changes.

pkg/base/config.go

@@ -143,6 +143,10 @@ const (
 	// DefaultDescriptorLeaseRenewalTimeout is the default time
 	// before a lease expires when acquisition to renew the lease begins.
 	DefaultDescriptorLeaseRenewalTimeout = time.Minute
+
+	// DefaultLeaseRenewalCrossValidate is the default setting for if
+	// we should validate descriptors on lease renewals.
+	DefaultLeaseRenewalCrossValidate = false
 )
 
 // DefaultCertsDirectory is the default value for the cert directory flag.

pkg/bench/rttanalysis/testdata/benchmark_expectations

@@ -99,5 +99,5 @@ exp,benchmark
 12,Truncate/truncate_2_column_2_rows
 1,VirtualTableQueries/select_crdb_internal.invalid_objects_with_1_fk
 1,VirtualTableQueries/select_crdb_internal.tables_with_1_fk
-11,VirtualTableQueries/virtual_table_cache_with_point_lookups
+9,VirtualTableQueries/virtual_table_cache_with_point_lookups
 7,VirtualTableQueries/virtual_table_cache_with_schema_change

pkg/sql/catalog/lease/storage.go

@@ -86,6 +86,14 @@ var LeaseRenewalDuration = settings.RegisterDurationSetting(
 	"controls the default time before a lease expires when acquisition to renew the lease begins",
 	base.DefaultDescriptorLeaseRenewalTimeout)
 
+// LeaseRenewalCrossValidate controls if cross validation should be done during
+// lease renewal.
+var LeaseRenewalCrossValidate = settings.RegisterBoolSetting(
+	settings.TenantWritable,
+	"sql.catalog.descriptor_lease_renewal_cross_validation.enabled",
+	"controls if cross validation should be done during lease renewal",
+	base.DefaultLeaseRenewalCrossValidate)
+
 func (s storage) leaseRenewalTimeout() time.Duration {
 	return LeaseRenewalDuration.Get(&s.settings.SV)
 }
@@ -99,6 +107,10 @@ func (s storage) jitteredLeaseDuration() time.Duration {
 		2*jitterFraction*rand.Float64()))
 }
 
+func (s storage) crossValidateDuringRenewal() bool {
+	return LeaseRenewalCrossValidate.Get(&s.settings.SV)
+}
+
 // acquire a lease on the most recent version of a descriptor. If the lease
 // cannot be obtained because the descriptor is in the process of being dropped
 // or offline (currently only applicable to tables), the error will be of type
@@ -148,7 +160,6 @@ func (s storage) acquire(
 			// a monotonically increasing expiration.
 			expiration = minExpiration.Add(int64(time.Millisecond), 0)
 		}
-
 		desc, err = s.mustGetDescriptorByID(ctx, txn, id)
 		if err != nil {
 			return err
@@ -291,13 +302,17 @@ func (s storage) mustGetDescriptorByID(
 		return nil, err
 	}
 	desc := c.LookupDescriptor(id)
+	validationLevel := catalog.ValidationLevelSelfOnly
+	if s.crossValidateDuringRenewal() {
+		validationLevel = validate.ImmutableRead
+	}
 	vd := catkv.NewCatalogReaderBackedValidationDereferencer(cr, txn, nil /* dvmpMaybe */)
 	ve := validate.Validate(
 		ctx,
 		s.settings.Version.ActiveVersion(ctx),
 		vd,
 		catalog.ValidationReadTelemetry,
-		validate.ImmutableRead,
+		validationLevel,
 		desc,
 	)
 	if err := ve.CombinedError(); err != nil {