SERVER-54981 Add recipientShards field to resharding donor document.

Changes "reshardingFields.donorFields" to be filled in as part of the
coordinator's transition to kPreparingToDonate.

11 files changed, 91 insertions, 46 deletions

diff --git a/src/mongo/db/s/collection_metadata_test.cpp b/src/mongo/db/s/collection_metadata_test.cpp
index d3b585f9d90..5bbf258a5ab 100644
--- a/src/mongo/db/s/collection_metadata_test.cpp
+++ b/src/mongo/db/s/collection_metadata_test.cpp
@@ -123,7 +123,8 @@ protected:
         } else if (state == CoordinatorStateEnum::kBlockingWrites) {
             TypeCollectionDonorFields donorFields{
                 constructTemporaryReshardingNss(kNss.db(), existingUuid),
-                KeyPattern{BSON("newKey" << 1)}};
+                KeyPattern{BSON("newKey" << 1)},
+                {kThisShard, kOtherShard}};
             reshardingFields.setDonorFields(std::move(donorFields));
         }
 
diff --git a/src/mongo/db/s/resharding/donor_document.idl b/src/mongo/db/s/resharding/donor_document.idl
index c282f93874c..c2847f01356 100644
--- a/src/mongo/db/s/resharding/donor_document.idl
+++ b/src/mongo/db/s/resharding/donor_document.idl
@@ -50,3 +50,6 @@ structs:
             # We intentionally have the mutable state nested in a subobject to make it easy to
             # overwrite with a single $set.
             mutableState: DonorShardContext
+            recipientShards:
+                type: array<shard_id>
+                description: "The list of recipient shards that are replicating from this donor."
diff --git a/src/mongo/db/s/resharding/resharding_coordinator_service.cpp b/src/mongo/db/s/resharding/resharding_coordinator_service.cpp
index e20b8f447ec..d1f046a4903 100644
--- a/src/mongo/db/s/resharding/resharding_coordinator_service.cpp
+++ b/src/mongo/db/s/resharding/resharding_coordinator_service.cpp
@@ -192,25 +192,12 @@ void writeToCoordinatorStateNss(OperationContext* opCtx,
 }
 
 /**
- * Extracts the ShardId from each Donor/RecipientShardEntry in participantShardEntries.
- */
-template <class T>
-std::vector<ShardId> extractShardIds(const std::vector<T>& participantShardEntries) {
-    std::vector<ShardId> shardIds(participantShardEntries.size());
-    std::transform(participantShardEntries.begin(),
-                   participantShardEntries.end(),
-                   shardIds.begin(),
-                   [](auto& shardEntry) { return shardEntry.getId(); });
-    return shardIds;
-}
-
-/**
  * Creates reshardingFields.recipientFields for the resharding operation. Note: these should not
  * change once the operation has begun.
  */
 TypeCollectionRecipientFields constructRecipientFields(
     const ReshardingCoordinatorDocument& coordinatorDoc) {
-    auto donorShardIds = extractShardIds(coordinatorDoc.getDonorShards());
+    auto donorShardIds = resharding::extractShardIds(coordinatorDoc.getDonorShards());
     TypeCollectionRecipientFields recipientFields(
         std::move(donorShardIds), coordinatorDoc.getSourceUUID(), coordinatorDoc.getSourceNss());
     emplaceFetchTimestampIfExists(recipientFields, coordinatorDoc.getFetchTimestamp());
@@ -229,9 +216,6 @@ BSONObj createReshardingFieldsUpdateForOriginalNss(
             TypeCollectionReshardingFields originalEntryReshardingFields(
                 coordinatorDoc.getReshardingUUID());
             originalEntryReshardingFields.setState(coordinatorDoc.getState());
-            TypeCollectionDonorFields donorField(coordinatorDoc.getTempReshardingNss(),
-                                                 coordinatorDoc.getReshardingKey());
-            originalEntryReshardingFields.setDonorFields(donorField);
 
             return BSON("$set" << BSON(CollectionType::kReshardingFieldsFieldName
                                        << originalEntryReshardingFields.toBSON()
@@ -239,6 +223,31 @@ BSONObj createReshardingFieldsUpdateForOriginalNss(
                                        << opCtx->getServiceContext()->getPreciseClockSource()->now()
                                        << CollectionType::kAllowMigrationsFieldName << false));
         }
+        case CoordinatorStateEnum::kPreparingToDonate: {
+            TypeCollectionDonorFields donorFields(
+                coordinatorDoc.getTempReshardingNss(),
+                coordinatorDoc.getReshardingKey(),
+                resharding::extractShardIds(coordinatorDoc.getRecipientShards()));
+
+            BSONObjBuilder updateBuilder;
+            {
+                BSONObjBuilder setBuilder(updateBuilder.subobjStart("$set"));
+                {
+                    setBuilder.append(CollectionType::kReshardingFieldsFieldName + "." +
+                                          TypeCollectionReshardingFields::kStateFieldName,
+                                      CoordinatorState_serializer(nextState));
+
+                    setBuilder.append(CollectionType::kReshardingFieldsFieldName + "." +
+                                          TypeCollectionReshardingFields::kDonorFieldsFieldName,
+                                      donorFields.toBSON());
+
+                    setBuilder.append(CollectionType::kUpdatedAtFieldName,
+                                      opCtx->getServiceContext()->getPreciseClockSource()->now());
+                }
+            }
+
+            return updateBuilder.obj();
+        }
         case CoordinatorStateEnum::kDecisionPersisted: {
             // Update the config.collections entry for the original nss to reflect
             // the new sharded collection. Set 'uuid' to the reshardingUUID, 'key' to the new shard
@@ -588,7 +597,7 @@ void bumpShardVersionsThenExecuteStateTransitionAndMetadataChangesInTxn(
         ShardingCatalogManager::get(opCtx)->bumpCollShardVersionsAndChangeMetadataInTxn(
             opCtx,
             updatedCoordinatorDoc.getSourceNss(),
-            extractShardIds(updatedCoordinatorDoc.getDonorShards()),
+            resharding::extractShardIds(updatedCoordinatorDoc.getDonorShards()),
             std::move(changeMetadataFunc));
     } else if (participantsToNotify == ParticipantsToNotifyEnum::kRecipients) {
         // Bump the recipient shard versions for the temporary resharding namespace along with
@@ -596,7 +605,7 @@ void bumpShardVersionsThenExecuteStateTransitionAndMetadataChangesInTxn(
         ShardingCatalogManager::get(opCtx)->bumpCollShardVersionsAndChangeMetadataInTxn(
             opCtx,
             updatedCoordinatorDoc.getTempReshardingNss(),
-            extractShardIds(updatedCoordinatorDoc.getRecipientShards()),
+            resharding::extractShardIds(updatedCoordinatorDoc.getRecipientShards()),
             std::move(changeMetadataFunc));
     } else if (participantsToNotify ==
                ParticipantsToNotifyEnum::kAllParticipantsPostDecisionPersisted) {
@@ -607,7 +616,7 @@ void bumpShardVersionsThenExecuteStateTransitionAndMetadataChangesInTxn(
         ShardingCatalogManager::get(opCtx)->bumpCollShardVersionsAndChangeMetadataInTxn(
             opCtx,
             updatedCoordinatorDoc.getSourceNss(),
-            extractShardIds(updatedCoordinatorDoc.getRecipientShards()),
+            resharding::extractShardIds(updatedCoordinatorDoc.getRecipientShards()),
             std::move(changeMetadataFunc));
     }
 }
@@ -1354,7 +1363,7 @@ void ReshardingCoordinatorService::ReshardingCoordinator::
 void ReshardingCoordinatorService::ReshardingCoordinator::_tellAllRecipientsToRefresh(
     const std::shared_ptr<executor::ScopedTaskExecutor>& executor) {
     auto opCtx = cc().makeOperationContext();
-    auto recipientIds = extractShardIds(_coordinatorDoc.getRecipientShards());
+    auto recipientIds = resharding::extractShardIds(_coordinatorDoc.getRecipientShards());
 
     NamespaceString nssToRefresh;
     // Refresh the temporary namespace if the coordinator is in state 'kError' just in case the
@@ -1375,7 +1384,7 @@ void ReshardingCoordinatorService::ReshardingCoordinator::_tellAllRecipientsToRe
 void ReshardingCoordinatorService::ReshardingCoordinator::_tellAllDonorsToRefresh(
     const std::shared_ptr<executor::ScopedTaskExecutor>& executor) {
     auto opCtx = cc().makeOperationContext();
-    auto donorIds = extractShardIds(_coordinatorDoc.getDonorShards());
+    auto donorIds = resharding::extractShardIds(_coordinatorDoc.getDonorShards());
     sharding_util::tellShardsToRefreshCollection(
         opCtx.get(), donorIds, _coordinatorDoc.getSourceNss(), **executor);
 }
@@ -1384,8 +1393,8 @@ void ReshardingCoordinatorService::ReshardingCoordinator::_tellAllParticipantsTo
     const BSONObj& refreshCmd, const std::shared_ptr<executor::ScopedTaskExecutor>& executor) {
     auto opCtx = cc().makeOperationContext();
 
-    auto donorShardIds = extractShardIds(_coordinatorDoc.getDonorShards());
-    auto recipientShardIds = extractShardIds(_coordinatorDoc.getRecipientShards());
+    auto donorShardIds = resharding::extractShardIds(_coordinatorDoc.getDonorShards());
+    auto recipientShardIds = resharding::extractShardIds(_coordinatorDoc.getRecipientShards());
     std::set<ShardId> participantShardIds{donorShardIds.begin(), donorShardIds.end()};
     participantShardIds.insert(recipientShardIds.begin(), recipientShardIds.end());
 
diff --git a/src/mongo/db/s/resharding/resharding_coordinator_service.h b/src/mongo/db/s/resharding/resharding_coordinator_service.h
index be8447a68f2..1e689b2781b 100644
--- a/src/mongo/db/s/resharding/resharding_coordinator_service.h
+++ b/src/mongo/db/s/resharding/resharding_coordinator_service.h
@@ -78,6 +78,19 @@ void writeStateTransitionAndCatalogUpdatesThenBumpShardVersions(
 void removeCoordinatorDocAndReshardingFields(OperationContext* opCtx,
                                              const ReshardingCoordinatorDocument& coordinatorDoc);
 
+/**
+ * Extracts the ShardId from each Donor/RecipientShardEntry in participantShardEntries.
+ */
+template <class T>
+std::vector<ShardId> extractShardIds(const std::vector<T>& participantShardEntries) {
+    std::vector<ShardId> shardIds(participantShardEntries.size());
+    std::transform(participantShardEntries.begin(),
+                   participantShardEntries.end(),
+                   shardIds.begin(),
+                   [](auto& shardEntry) { return shardEntry.getId(); });
+    return shardIds;
+}
+
 }  // namespace resharding
 
 class ServiceContext;
diff --git a/src/mongo/db/s/resharding/resharding_coordinator_test.cpp b/src/mongo/db/s/resharding/resharding_coordinator_test.cpp
index 99f8285d2b8..67450a78bed 100644
--- a/src/mongo/db/s/resharding/resharding_coordinator_test.cpp
+++ b/src/mongo/db/s/resharding/resharding_coordinator_test.cpp
@@ -198,7 +198,9 @@ protected:
         TypeCollectionReshardingFields reshardingFields(coordinatorDoc.getReshardingUUID());
         reshardingFields.setState(coordinatorDoc.getState());
         reshardingFields.setDonorFields(TypeCollectionDonorFields(
-            coordinatorDoc.getTempReshardingNss(), coordinatorDoc.getReshardingKey()));
+            coordinatorDoc.getTempReshardingNss(),
+            coordinatorDoc.getReshardingKey(),
+            resharding::extractShardIds(coordinatorDoc.getRecipientShards())));
 
         auto originalNssCatalogEntry = makeOriginalCollectionCatalogEntry(
             coordinatorDoc,
@@ -470,8 +472,10 @@ protected:
         TypeCollectionReshardingFields expectedReshardingFields(
             expectedCoordinatorDoc.getReshardingUUID());
         expectedReshardingFields.setState(expectedCoordinatorDoc.getState());
-        TypeCollectionDonorFields donorField(expectedCoordinatorDoc.getTempReshardingNss(),
-                                             expectedCoordinatorDoc.getReshardingKey());
+        TypeCollectionDonorFields donorField(
+            expectedCoordinatorDoc.getTempReshardingNss(),
+            expectedCoordinatorDoc.getReshardingKey(),
+            resharding::extractShardIds(expectedCoordinatorDoc.getRecipientShards()));
         expectedReshardingFields.setDonorFields(donorField);
         if (auto abortReason = expectedCoordinatorDoc.getAbortReason()) {
             AbortReason abortReasonStruct;
@@ -518,9 +522,10 @@ protected:
             TypeCollectionReshardingFields reshardingFields(
                 expectedCoordinatorDoc.getReshardingUUID());
             reshardingFields.setState(expectedCoordinatorDoc.getState());
-            reshardingFields.setDonorFields(
-                TypeCollectionDonorFields(expectedCoordinatorDoc.getTempReshardingNss(),
-                                          expectedCoordinatorDoc.getReshardingKey()));
+            reshardingFields.setDonorFields(TypeCollectionDonorFields(
+                expectedCoordinatorDoc.getTempReshardingNss(),
+                expectedCoordinatorDoc.getReshardingKey(),
+                resharding::extractShardIds(expectedCoordinatorDoc.getRecipientShards())));
 
             auto originalNssCatalogEntry = makeOriginalCollectionCatalogEntry(
                 expectedCoordinatorDoc,
diff --git a/src/mongo/db/s/resharding/resharding_donor_recipient_common.cpp b/src/mongo/db/s/resharding/resharding_donor_recipient_common.cpp
index 0ad26e7eae1..18d10d50547 100644
--- a/src/mongo/db/s/resharding/resharding_donor_recipient_common.cpp
+++ b/src/mongo/db/s/resharding/resharding_donor_recipient_common.cpp
@@ -261,18 +261,28 @@ void processReshardingFieldsForRecipientCollection(OperationContext* opCtx,
 void verifyValidReshardingFields(const ReshardingFields& reshardingFields) {
     auto coordinatorState = reshardingFields.getState();
 
-    if (coordinatorState < CoordinatorStateEnum::kDecisionPersisted) {
+    if (coordinatorState < CoordinatorStateEnum::kPreparingToDonate) {
+        // Prior to the state CoordinatorStateEnum::kPreparingToDonate, the source collection's
+        // config.collections entry won't have "donorFields". Additionally, the temporary resharding
+        // collection's config.collections entry won't exist yet.
+        uassert(5498100,
+                fmt::format("reshardingFields must not contain donorFields or recipientFields when"
+                            " the coordinator is in state {}. Got reshardingFields {}",
+                            CoordinatorState_serializer(reshardingFields.getState()),
+                            reshardingFields.toBSON().toString()),
+                !reshardingFields.getDonorFields() && !reshardingFields.getRecipientFields());
+    } else if (coordinatorState < CoordinatorStateEnum::kDecisionPersisted) {
         // Prior to the state CoordinatorStateEnum::kDecisionPersisted, only the source
         // collection's config.collections entry should have donorFields, and only the
         // temporary resharding collection's entry should have recipientFields.
         uassert(5274201,
-                fmt::format("reshardingFields must contain either donorFields or recipientFields "
-                            "(and not both) when the "
-                            "coordinator is in state {}. Got reshardingFields {}",
+                fmt::format("reshardingFields must contain exactly one of donorFields and"
+                            " recipientFields when the coordinator is in state {}. Got"
+                            " reshardingFields {}",
                             CoordinatorState_serializer(reshardingFields.getState()),
                             reshardingFields.toBSON().toString()),
-                reshardingFields.getDonorFields().is_initialized() ^
-                    reshardingFields.getRecipientFields().is_initialized());
+                bool(reshardingFields.getDonorFields()) !=
+                    bool(reshardingFields.getRecipientFields()));
     } else {
         // At and after state CoordinatorStateEnum::kDecisionPersisted, the temporary
         // resharding collection's config.collections entry has been removed, and so the
@@ -295,7 +305,8 @@ ReshardingDonorDocument constructDonorDocumentFromReshardingFields(
     DonorShardContext donorCtx;
     donorCtx.setState(DonorStateEnum::kPreparingToDonate);
 
-    auto donorDoc = ReshardingDonorDocument{std::move(donorCtx)};
+    auto donorDoc = ReshardingDonorDocument{
+        std::move(donorCtx), reshardingFields.getDonorFields()->getRecipientShardIds()};
 
     auto sourceUUID = getCollectionUUIDFromChunkManger(nss, *metadata.getChunkManager());
     auto commonMetadata =
diff --git a/src/mongo/db/s/resharding/resharding_donor_recipient_common_test.h b/src/mongo/db/s/resharding/resharding_donor_recipient_common_test.h
index 790f6eb5ddb..6deff9cafdd 100644
--- a/src/mongo/db/s/resharding/resharding_donor_recipient_common_test.h
+++ b/src/mongo/db/s/resharding/resharding_donor_recipient_common_test.h
@@ -135,7 +135,8 @@ protected:
 
     void appendDonorFieldsToReshardingFields(ReshardingFields& fields,
                                              const BSONObj& reshardingKey) {
-        fields.setDonorFields(TypeCollectionDonorFields(kTemporaryReshardingNss, reshardingKey));
+        fields.setDonorFields(
+            TypeCollectionDonorFields(kTemporaryReshardingNss, reshardingKey, kShardIds));
     }
 
     void appendRecipientFieldsToReshardingFields(
diff --git a/src/mongo/db/s/resharding/resharding_donor_service.cpp b/src/mongo/db/s/resharding/resharding_donor_service.cpp
index 79c16d97ddf..05aaf0b4d05 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service.cpp
+++ b/src/mongo/db/s/resharding/resharding_donor_service.cpp
@@ -142,6 +142,7 @@ ReshardingDonorService::DonorStateMachine::DonorStateMachine(
     const ReshardingDonorDocument& donorDoc)
     : repl::PrimaryOnlyService::TypedInstance<DonorStateMachine>(),
       _metadata{donorDoc.getCommonReshardingMetadata()},
+      _recipientShardIds{donorDoc.getRecipientShards()},
       _donorCtx{donorDoc.getMutableState()} {}
 
 ReshardingDonorService::DonorStateMachine::~DonorStateMachine() {
@@ -373,10 +374,7 @@ void ReshardingDonorService::DonorStateMachine::
         try {
             Timer latency;
 
-            const auto recipients =
-                getRecipientShards(rawOpCtx, _metadata.getSourceNss(), _metadata.getSourceUUID());
-
-            for (const auto& recipient : recipients) {
+            for (const auto& recipient : _recipientShardIds) {
                 auto oplog = generateOplogEntry(recipient);
                 writeConflictRetry(
                     rawOpCtx,
@@ -403,7 +401,7 @@ void ReshardingDonorService::DonorStateMachine::
                             "Committed oplog entries to temporarily block writes for resharding",
                             "namespace"_attr = _metadata.getSourceNss(),
                             "reshardingUUID"_attr = _metadata.getReshardingUUID(),
-                            "numRecipients"_attr = recipients.size(),
+                            "numRecipients"_attr = _recipientShardIds.size(),
                             "duration"_attr = duration_cast<Milliseconds>(latency.elapsed()));
                 ensureFulfilledPromise(lg, _finalOplogEntriesWritten);
             }
diff --git a/src/mongo/db/s/resharding/resharding_donor_service.h b/src/mongo/db/s/resharding/resharding_donor_service.h
index 1f73febf005..da1296b562d 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service.h
+++ b/src/mongo/db/s/resharding/resharding_donor_service.h
@@ -151,6 +151,7 @@ private:
     // The in-memory representation of the immutable portion of the document in
     // config.localReshardingOperations.donor.
     const CommonReshardingMetadata _metadata;
+    const std::vector<ShardId> _recipientShardIds;
 
     // The in-memory representation of the mutable portion of the document in
     // config.localReshardingOperations.donor.
diff --git a/src/mongo/db/s/resharding/resharding_donor_service_test.cpp b/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
index 6f686c59731..1c8e5842eac 100644
--- a/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
+++ b/src/mongo/db/s/resharding/resharding_donor_service_test.cpp
@@ -193,7 +193,7 @@ TEST_F(ReshardingDonorServiceTest,
     DonorShardContext donorCtx;
     donorCtx.setState(DonorStateEnum::kPreparingToBlockWrites);
 
-    ReshardingDonorDocument doc(std::move(donorCtx));
+    ReshardingDonorDocument doc(std::move(donorCtx), kRecipientShards);
     CommonReshardingMetadata metadata(kReshardingUUID,
                                       mongo::NamespaceString(kReshardNs),
                                       kExistingUUID,
diff --git a/src/mongo/db/s/resharding_destined_recipient_test.cpp b/src/mongo/db/s/resharding_destined_recipient_test.cpp
index 7d932c4eb0e..ec16834362b 100644
--- a/src/mongo/db/s/resharding_destined_recipient_test.cpp
+++ b/src/mongo/db/s/resharding_destined_recipient_test.cpp
@@ -201,7 +201,10 @@ protected:
 
         TypeCollectionReshardingFields reshardingFields;
         reshardingFields.setReshardingUUID(UUID::gen());
-        reshardingFields.setDonorFields(TypeCollectionDonorFields{env.tempNss, BSON("y" << 1)});
+        reshardingFields.setDonorFields(TypeCollectionDonorFields{
+            env.tempNss,
+            BSON("y" << 1),
+            {ShardId{kShardList[0].getName()}, ShardId{kShardList[1].getName()}}});
         reshardingFields.setState(CoordinatorStateEnum::kPreparingToDonate);
 
         CollectionType coll(kNss, env.version.epoch(), Date_t::now(), UUID::gen());