mmaprototypehelpers: skip mma coordination when mma is disabled

Previously, non-mma components registered external changes with mma via
allocator sync even when mma was disabled. This led to logs like `did not
register external changes: due to range does not exist in cluster state`.
Without mma being enabled, mma can’t register external changes because it never
learns about the ranges via processStoreLeaseholderMsg in the first place, and
this external change would get dropped. This commit changes allocator sync to
skip coordinating with the mma allocator when mma is disabled. Note that we
changes still go via allocator sync even when mma is disabled to update the
local store pool correctly.

Epic: none
Release note: none

Author: wenyihu6

pkg/kv/kvserver/allocator/mmaprototypehelpers/BUILD.bazel

@@ -10,10 +10,12 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/kv/kvpb",
+        "//pkg/kv/kvserver",
         "//pkg/kv/kvserver/allocator",
         "//pkg/kv/kvserver/allocator/mmaprototype",
         "//pkg/kv/kvserver/allocator/storepool",
         "//pkg/roachpb",
+        "//pkg/settings/cluster",
         "//pkg/util/log",
         "//pkg/util/syncutil",
         "//pkg/util/timeutil",

pkg/kv/kvserver/allocator/mmaprototypehelpers/kvserver_mma_integration.go

@@ -10,10 +10,12 @@ import (
 	"fmt"
 
 	"github.com/cockroachdb/cockroach/pkg/kv/kvpb"
+	"github.com/cockroachdb/cockroach/pkg/kv/kvserver"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/allocator"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/allocator/mmaprototype"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/allocator/storepool"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
+	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
 )
@@ -62,17 +64,21 @@ func (s Author) External() bool {
 type AllocatorSync struct {
 	sp          *storepool.StorePool
 	mmAllocator mmaprototype.Allocator
+	st          *cluster.Settings
 	mu          struct {
 		syncutil.Mutex
 		changeSeqGen   SyncChangeID
 		trackedChanges map[SyncChangeID]trackedAllocatorChange
 	}
 }
 
-func NewAllocatorSync(sp *storepool.StorePool, mmAllocator mmaprototype.Allocator) *AllocatorSync {
+func NewAllocatorSync(
+	sp *storepool.StorePool, mmAllocator mmaprototype.Allocator, st *cluster.Settings,
+) *AllocatorSync {
 	as := &AllocatorSync{
 		sp:          sp,
 		mmAllocator: mmAllocator,
+		st:          st,
 	}
 	as.mu.trackedChanges = make(map[SyncChangeID]trackedAllocatorChange)
 	return as
@@ -122,9 +128,12 @@ func (as *AllocatorSync) NonMMAPreTransferLease(
 	)
 	log.Infof(ctx, "registering external lease transfer change: usage=%v changes=%v",
 		usage, replicaChanges)
-	changeIDs := as.mmAllocator.RegisterExternalChanges(replicaChanges[:])
-	if changeIDs == nil {
-		log.Info(ctx, "mma did not track lease transfer, skipping")
+	var changeIDs []mmaprototype.ChangeID
+	if kvserver.LoadBasedRebalancingMode.Get(&as.st.SV) == kvserver.LBRebalancingMultiMetric {
+		changeIDs = as.mmAllocator.RegisterExternalChanges(replicaChanges[:])
+		if changeIDs == nil {
+			log.Info(ctx, "mma did not track lease transfer, skipping")
+		}
 	}
 	trackedChange := trackedAllocatorChange{
 		typ:          AllocatorChangeTypeLeaseTransfer,
@@ -210,9 +219,12 @@ func (as *AllocatorSync) NonMMAPreChangeReplicas(
 
 	log.Infof(ctx, "registering external replica change: chgs=%v usage=%v changes=%v",
 		changes, usage, replicaChanges)
-	changeIDs := as.mmAllocator.RegisterExternalChanges(replicaChanges)
-	if changeIDs == nil {
-		log.Info(ctx, "cluster does not have a range for the external replica change, skipping")
+	var changeIDs []mmaprototype.ChangeID
+	if kvserver.LoadBasedRebalancingMode.Get(&as.st.SV) == kvserver.LBRebalancingMultiMetric {
+		changeIDs = as.mmAllocator.RegisterExternalChanges(replicaChanges)
+		if changeIDs == nil {
+			log.Info(ctx, "cluster does not have a range for the external replica change, skipping")
+		}
 	}
 	trackedChange := trackedAllocatorChange{
 		typ:       AllocatorChangeTypeChangeReplicas,
@@ -335,12 +347,14 @@ func (as *AllocatorSync) PostApply(ctx context.Context, syncChangeID SyncChangeI
 		}
 		delete(as.mu.trackedChanges, syncChangeID)
 	}()
-	if changeIDs := tracked.changeIDs; changeIDs != nil {
-		log.Infof(ctx, "PostApply: tracked=%v change_ids=%v success: %v", tracked, changeIDs, success)
-		as.updateMetrics(success, tracked.typ, tracked.author)
-		as.mmAllocator.AdjustPendingChangesDisposition(changeIDs, success)
-	} else {
-		log.Infof(ctx, "PostApply: tracked=%v no change_ids success: %v", tracked, success)
+	if kvserver.LoadBasedRebalancingMode.Get(&as.st.SV) == kvserver.LBRebalancingMultiMetric {
+		if changeIDs := tracked.changeIDs; changeIDs != nil {
+			log.Infof(ctx, "PostApply: tracked=%v change_ids=%v success: %v", tracked, changeIDs, success)
+			as.updateMetrics(success, tracked.typ, tracked.author)
+			as.mmAllocator.AdjustPendingChangesDisposition(changeIDs, success)
+		} else {
+			log.Infof(ctx, "PostApply: tracked=%v no change_ids success: %v", tracked, success)
+		}
 	}
 	as.updateMetrics(success, tracked.typ, tracked.author)
 	if !success {

pkg/kv/kvserver/asim/state/impl.go

@@ -430,9 +430,9 @@ func (s *state) AddNode() Node {
 		nodeID:      nodeID,
 		desc:        roachpb.NodeDescriptor{NodeID: roachpb.NodeID(nodeID)},
 		stores:      []StoreID{},
-		storepool:   sp,
 		mmAllocator: mmAllocator,
-		as:          mmaprototypehelpers.NewAllocatorSync(sp, mmAllocator),
+		storepool:   sp,
+		as:          mmaprototypehelpers.NewAllocatorSync(sp, mmAllocator, s.settings.ST),
 	}
 	s.nodes[nodeID] = node
 	s.SetNodeLiveness(nodeID, livenesspb.NodeLivenessStatus_LIVE)