mmaintegration: address minor code review comments

This commit address minor code review comments.

Author: wenyihu6

pkg/kv/kvserver/lease_queue.go

@@ -150,11 +150,9 @@ func (lq *leaseQueue) process(
 		// changes to store pool and inform mma.
 		lq.as.PostApply(changeID, err == nil /*success*/)
 		if err != nil {
-			// TODO(wenyihu6): we need to call post apply with false when as is more meaningful
 			return false, errors.Wrapf(err, "%s: unable to transfer lease to s%d", repl, transferOp.Target)
 		}
 	}
-
 	return true, nil
 }
 

pkg/kv/kvserver/mmaintegration/allocator_op.go

@@ -22,7 +22,7 @@ type trackedAllocatorChange struct {
 	changeIDs []mmaprototype.ChangeID
 	// Usage is range load usage.
 	usage allocator.RangeUsageInfo
-	// Only one of the following two fields will be set.
+	// Exactly one of the following two fields will be set.
 	leaseTransferOp  *leaseTransferOp
 	changeReplicasOp *changeReplicasOp
 }

pkg/kv/kvserver/mmaintegration/allocator_sync.go

@@ -32,10 +32,10 @@ type SyncChangeID uint64
 // has been disabled postapply or other components call into allocator sync when
 // mma is disabled.)
 
-// AllocatorSync is a component that coordinates changes from external
-// components (e.g. replicate/lease queue) with mma. When mma is disabled,
-// its sole purpose is to track and apply changes to the store pool upon
-// success.
+// AllocatorSync is a component that coordinates changes from all components
+// (including mma/replicate/lease queue) with mma and store pool. When mma is
+// disabled, its sole purpose is to track and apply changes to the store pool
+// upon success.
 type AllocatorSync struct {
 	sp           *storepool.StorePool
 	st           *cluster.Settings
@@ -85,7 +85,7 @@ func mmaRangeLoad(rangeUsageInfo allocator.RangeUsageInfo) mmaprototype.RangeLoa
 func (as *AllocatorSync) addTrackedChange(change trackedAllocatorChange) SyncChangeID {
 	as.mu.Lock()
 	defer as.mu.Unlock()
-	as.mu.changeSeqGen += 1
+	as.mu.changeSeqGen++
 	syncChangeID := as.mu.changeSeqGen
 	as.mu.trackedChanges[syncChangeID] = change
 	return syncChangeID

pkg/kv/kvserver/mmaintegration/mma_conversion.go

@@ -23,8 +23,8 @@ func convertLeaseTransferToMMA(
 	transferFrom, transferTo roachpb.ReplicationTarget,
 ) []mmaprototype.ReplicaChange {
 	// TODO(wenyihu6): we are passing existing replicas to
-	// mma.RegisterExternalChanges just to get the add and remove replica state.
-	// See if things could be cleaned up.
+	// mmaprototype.MakeLeaseTransferChanges just to get the add and remove
+	// replica state. See if things could be cleaned up.
 	existingReplicas := make([]mmaprototype.StoreIDAndReplicaState, len(desc.InternalReplicas))
 	for i, replica := range desc.Replicas().Descriptors() {
 		existingReplicas[i] = mmaprototype.StoreIDAndReplicaState{