SERVER-44161 Implement MigrationCoordinator

13 files changed, 498 insertions, 25 deletions

diff --git a/src/mongo/db/namespace_string.cpp b/src/mongo/db/namespace_string.cpp
index 8d8656b8ec4..2397e3c1d0d 100644
--- a/src/mongo/db/namespace_string.cpp
+++ b/src/mongo/db/namespace_string.cpp
@@ -66,6 +66,9 @@ const NamespaceString NamespaceString::kSessionTransactionsTableNamespace(
 const NamespaceString NamespaceString::kTransactionCoordinatorsNamespace(
     NamespaceString::kConfigDb, "transaction_coordinators");
 
+const NamespaceString NamespaceString::kMigrationCoordinatorsNamespace(NamespaceString::kConfigDb,
+                                                                       "migrationCoordinators");
+
 const NamespaceString NamespaceString::kShardConfigCollectionsNamespace(NamespaceString::kConfigDb,
                                                                         "cache.collections");
 const NamespaceString NamespaceString::kShardConfigDatabasesNamespace(NamespaceString::kConfigDb,
diff --git a/src/mongo/db/namespace_string.h b/src/mongo/db/namespace_string.h
index 653f0ed1546..add77a0dfaf 100644
--- a/src/mongo/db/namespace_string.h
+++ b/src/mongo/db/namespace_string.h
@@ -95,6 +95,9 @@ public:
     // Namespace for storing the persisted state of transaction coordinators.
     static const NamespaceString kTransactionCoordinatorsNamespace;
 
+    // Namespace for storing the persisted state of migration coordinators.
+    static const NamespaceString kMigrationCoordinatorsNamespace;
+
     // Namespace for replica set configuration settings.
     static const NamespaceString kSystemReplSetNamespace;
 
diff --git a/src/mongo/db/s/SConscript b/src/mongo/db/s/SConscript
index bbed7e25b50..6e4080a39b1 100644
--- a/src/mongo/db/s/SConscript
+++ b/src/mongo/db/s/SConscript
@@ -47,6 +47,7 @@ env.Library(
         'metadata_manager.cpp',
         'migration_chunk_cloner_source_legacy.cpp',
         'migration_chunk_cloner_source.cpp',
+        'migration_coordinator.cpp',
         'migration_destination_manager.cpp',
         'migration_session_id.cpp',
         'migration_source_manager.cpp',
@@ -74,7 +75,7 @@ env.Library(
         'start_chunk_clone_request.cpp',
         env.Idlc('sharding_runtime_d_params.idl')[0],
         env.Idlc('range_deletion_task.idl')[0],
-
+        env.Idlc('migration_coordinator_document.idl')[0],
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/db/catalog/multi_index_block',
diff --git a/src/mongo/db/s/migration_coordinator.cpp b/src/mongo/db/s/migration_coordinator.cpp
new file mode 100644
index 00000000000..f1deb950a17
--- /dev/null
+++ b/src/mongo/db/s/migration_coordinator.cpp
@@ -0,0 +1,103 @@
+/**
+ *    Copyright (C) 2019-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kSharding
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/s/migration_coordinator.h"
+
+#include "mongo/db/s/migration_util.h"
+#include "mongo/db/s/range_deletion_task_gen.h"
+#include "mongo/util/log.h"
+
+namespace mongo {
+namespace migrationutil {
+
+MigrationCoordinator::MigrationCoordinator(OperationContext* opCtx,
+                                           UUID migrationId,
+                                           ShardId donorShard,
+                                           ShardId recipientShard,
+                                           NamespaceString collectionNamespace,
+                                           UUID collectionUuid,
+                                           ChunkRange range)
+    : _migrationInfo(migrationId,
+                     std::move(collectionNamespace),
+                     collectionUuid,
+                     std::move(donorShard),
+                     std::move(recipientShard),
+                     std::move(range)) {}
+
+MigrationCoordinator::~MigrationCoordinator() = default;
+
+void MigrationCoordinator::startMigration(OperationContext* opCtx, bool waitForDelete) {
+    migrationutil::persistMigrationCoordinatorLocally(opCtx, _migrationInfo);
+
+    RangeDeletionTask donorDeletionTask(_migrationInfo.getId(),
+                                        _migrationInfo.getNss(),
+                                        _migrationInfo.getCollectionUuid(),
+                                        _migrationInfo.getDonorShardId(),
+                                        _migrationInfo.getRange(),
+                                        waitForDelete ? CleanWhenEnum::kNow
+                                                      : CleanWhenEnum::kDelayed);
+    donorDeletionTask.setPending(true);
+
+    LOG(0) << "Persisting range deletion task on donor for migration " << _migrationInfo.getId();
+    migrationutil::persistRangeDeletionTaskLocally(opCtx, donorDeletionTask);
+}
+
+void MigrationCoordinator::commitMigrationOnDonorAndRecipient(OperationContext* opCtx) {
+    LOG(0) << "Committing migration on donor and recipient for migration "
+           << _migrationInfo.getId();
+    LOG(0) << "Deleting range deletion task on recipient for migration " << _migrationInfo.getId();
+
+    migrationutil::deleteRangeDeletionTaskOnRecipient(
+        opCtx, _migrationInfo.getRecipientShardId(), _migrationInfo.getId());
+
+    LOG(0) << "Marking range deletion task on donor as ready for processing for migration "
+           << _migrationInfo.getId();
+    migrationutil::markAsReadyRangeDeletionTaskLocally(opCtx, _migrationInfo.getId());
+}
+
+void MigrationCoordinator::abortMigrationOnDonorAndRecipient(OperationContext* opCtx) {
+    LOG(0) << "Aborting migration on donor and recipient for migration " << _migrationInfo.getId();
+    LOG(0) << "Deleting range deletion task on donor for migration " << _migrationInfo.getId();
+
+    migrationutil::deleteRangeDeletionTaskLocally(opCtx, _migrationInfo.getId());
+
+    LOG(0) << "Marking range deletion task on recipient as ready for processing for migration "
+           << _migrationInfo.getId();
+
+    migrationutil::markAsReadyRangeDeletionTaskOnRecipient(
+        opCtx, _migrationInfo.getRecipientShardId(), _migrationInfo.getId());
+}
+
+}  // namespace migrationutil
+
+}  // namespace mongo
diff --git a/src/mongo/db/s/migration_coordinator.h b/src/mongo/db/s/migration_coordinator.h
new file mode 100644
index 00000000000..c0c2327a2c2
--- /dev/null
+++ b/src/mongo/db/s/migration_coordinator.h
@@ -0,0 +1,88 @@
+/**
+ *    Copyright (C) 2019-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/s/migration_coordinator_document_gen.h"
+#include "mongo/s/catalog/type_chunk.h"
+
+namespace mongo {
+
+namespace migrationutil {
+/**
+ * Manages the migration commit/abort process, including updates to config.rangeDeletions on the
+ * donor and the recipient, and updates to the routing table on the config server.
+ *
+ * TODO (SERVER-44716): Implement commit/abort/recovery logic on the config server.
+ */
+class MigrationCoordinator {
+public:
+    MigrationCoordinator(OperationContext* opCtx,
+                         UUID migrationId,
+                         ShardId donorShard,
+                         ShardId recipientShard,
+                         NamespaceString collectionNamespace,
+                         UUID collectionUuid,
+                         ChunkRange range);
+    MigrationCoordinator(const MigrationCoordinator&) = delete;
+    MigrationCoordinator& operator=(const MigrationCoordinator&) = delete;
+    MigrationCoordinator(MigrationCoordinator&&) = delete;
+    MigrationCoordinator& operator=(MigrationCoordinator&&) = delete;
+
+    ~MigrationCoordinator();
+
+    /**
+     * Initializes persistent state required to ensure that orphaned ranges are properly handled,
+     * even after failover, by doing the following:
+     *
+     * 1) Inserts a document into the local config.migrationCoordinators with the lsid, txnNumber,
+     * and recipientId and waits for majority writeConcern.
+     * 2) Inserts a document into the local config.rangeDeletions with the collectionUUID, range to
+     * delete, and "pending: true" and waits for majority writeConcern.
+     */
+    void startMigration(OperationContext* opCtx, bool waitForDelete);
+
+    /**
+     * Deletes the range deletion task from the recipient node and marks the range deletion task on
+     * the donor as ready to be processed.
+     */
+    void commitMigrationOnDonorAndRecipient(OperationContext* opCtx);
+
+    /**
+     * Deletes the range deletion task from the donor node and marks the range deletion task on the
+     * recipient node as ready to be processed.
+     */
+    void abortMigrationOnDonorAndRecipient(OperationContext* opCtx);
+
+private:
+    MigrationCoordinatorDocument _migrationInfo;
+};
+
+}  // namespace migrationutil
+}  // namespace mongo
diff --git a/src/mongo/db/s/migration_coordinator_document.idl b/src/mongo/db/s/migration_coordinator_document.idl
new file mode 100644
index 00000000000..ff12d7e51f5
--- /dev/null
+++ b/src/mongo/db/s/migration_coordinator_document.idl
@@ -0,0 +1,65 @@
+# Copyright (C) 2019-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+
+# This file defines the format of documents stored in config.rangeDeletions. Each document
+# represents a chunk range to be deleted by the CollectionRangeDeleter.
+
+global:
+    cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+    - "mongo/s/sharding_types.idl"
+    - "mongo/s/chunk_range.idl"
+    - "mongo/db/logical_session_id.idl"
+
+structs:
+    migrationCoordinatorDocument:
+        description: "Represents an in-progress migration on the migration donor."
+        generate_comparison_operators: false
+        strict: true
+        fields:
+            _id:
+                type: uuid
+                description: "A unique identifier for the migration."
+                cpp_name: id
+            nss:
+                type: namespacestring
+                description: "The namespace of the collection that the chunk belongs to."
+            collectionUuid:
+                type: uuid
+                description: "The UUID of the collection that the chunk belongs to."
+            donorShardId:
+                type: shard_id
+                description: "The shard from which the chunk is being migrated."
+            recipientShardId:
+                type: shard_id
+                description: "The shard to which the chunk is being migrated."
+            range:
+                type: chunk_range
+                description: "The range being migrated."
diff --git a/src/mongo/db/s/migration_util.cpp b/src/mongo/db/s/migration_util.cpp
index afda204d544..bd5e2ac09da 100644
--- a/src/mongo/db/s/migration_util.cpp
+++ b/src/mongo/db/s/migration_util.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2018-present MongoDB, Inc.
+ *    Copyright (C) 2019-present MongoDB, Inc.
  *
  *    This program is free software: you can redistribute it and/or modify
  *    it under the terms of the Server Side Public License, version 1,
@@ -37,12 +37,19 @@
 #include "mongo/bson/bsonobjbuilder.h"
 #include "mongo/client/query.h"
 #include "mongo/db/catalog_raii.h"
+#include "mongo/db/dbdirectclient.h"
+#include "mongo/db/logical_session_cache.h"
 #include "mongo/db/namespace_string.h"
+#include "mongo/db/ops/write_ops.h"
+#include "mongo/db/repl/repl_client_info.h"
 #include "mongo/db/s/collection_sharding_runtime.h"
 #include "mongo/db/s/shard_filtering_metadata_refresh.h"
+#include "mongo/db/write_concern.h"
 #include "mongo/executor/task_executor_pool.h"
 #include "mongo/executor/thread_pool_task_executor.h"
+#include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/s/catalog/type_chunk.h"
+#include "mongo/s/client/shard.h"
 #include "mongo/s/grid.h"
 #include "mongo/util/log.h"
 
@@ -55,6 +62,27 @@ const char kDestinationShard[] = "destination";
 const char kIsDonorShard[] = "isDonorShard";
 const char kChunk[] = "chunk";
 const char kCollection[] = "collection";
+
+const WriteConcernOptions kMajorityWriteConcern(WriteConcernOptions::kMajority,
+                                                WriteConcernOptions::SyncMode::UNSET,
+                                                WriteConcernOptions::kNoTimeout);
+
+template <typename Cmd>
+void sendToRecipient(OperationContext* opCtx, const ShardId& recipientId, const Cmd& cmd) {
+    auto recipientShard =
+        uassertStatusOK(Grid::get(opCtx)->shardRegistry()->getShard(opCtx, recipientId));
+
+    LOG(1) << "Sending request " << cmd.toBSON({}) << " to recipient.";
+
+    auto response = recipientShard->runCommandWithFixedRetryAttempts(
+        opCtx,
+        ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+        "config",
+        cmd.toBSON({}),
+        Shard::RetryPolicy::kIdempotent);
+    uassertStatusOK(Shard::CommandResponse::getEffectiveStatus(response));
+}
+
 }  // namespace
 
 BSONObj makeMigrationStatusDocument(const NamespaceString& nss,
@@ -118,7 +146,7 @@ bool submitRangeDeletionTask(OperationContext* opCtx, const RangeDeletionTask& d
         return false;
     }
 
-    auto notification = css->cleanUpRange(*deletionTask.getRange(), whenToClean);
+    auto notification = css->cleanUpRange(deletionTask.getRange(), whenToClean);
 
     if (notification.ready() && !notification.waitStatus(opCtx).isOK()) {
         LOG(0) << "Failed to resubmit range for deletion: "
@@ -170,6 +198,80 @@ void resubmitRangeDeletionsOnStepUp(ServiceContext* serviceContext) {
     });
 }
 
-}  // namespace migrationutil
+void persistMigrationCoordinatorLocally(OperationContext* opCtx,
+                                        const MigrationCoordinatorDocument& migrationDoc) {
+    PersistentTaskStore<MigrationCoordinatorDocument> store(
+        opCtx, NamespaceString::kMigrationCoordinatorsNamespace);
+    try {
+        store.add(opCtx, migrationDoc);
+    } catch (const ExceptionFor<ErrorCodes::DuplicateKey>& e) {
+        // Convert a DuplicateKey error to an anonymous error.
+        uasserted(
+            31374,
+            str::stream() << "While attempting to write migration information for migration "
+                          << ", found document with the same migration id. Attempted migration: "
+                          << migrationDoc.toBSON());
+    }
+}
+
+void persistRangeDeletionTaskLocally(OperationContext* opCtx,
+                                     const RangeDeletionTask& deletionTask) {
+    PersistentTaskStore<RangeDeletionTask> store(opCtx, NamespaceString::kRangeDeletionNamespace);
+    try {
+        store.add(opCtx, deletionTask);
+    } catch (const ExceptionFor<ErrorCodes::DuplicateKey>& e) {
+        // Convert a DuplicateKey error to an anonymous error.
+        uasserted(31375,
+                  str::stream() << "While attempting to write range deletion task for migration "
+                                << ", found document with the same migration id. Attempted range "
+                                   "deletion task: "
+                                << deletionTask.toBSON());
+    }
+}
+
+void deleteRangeDeletionTaskOnRecipient(OperationContext* opCtx,
+                                        const ShardId& recipientId,
+                                        const UUID& migrationId) {
+    write_ops::Delete deleteOp(NamespaceString::kRangeDeletionNamespace);
+    write_ops::DeleteOpEntry query(BSON(RangeDeletionTask::kIdFieldName << migrationId),
+                                   false /*multi*/);
+    deleteOp.setDeletes({query});
 
+    sendToRecipient(opCtx, recipientId, deleteOp);
+}
+
+void deleteRangeDeletionTaskLocally(OperationContext* opCtx, const UUID& deletionTaskId) {
+    PersistentTaskStore<RangeDeletionTask> store(opCtx, NamespaceString::kRangeDeletionNamespace);
+    store.remove(opCtx, QUERY(RangeDeletionTask::kIdFieldName << deletionTaskId));
+}
+
+void deleteRangeDeletionTasksForCollectionLocally(OperationContext* opCtx,
+                                                  const UUID& collectionUuid) {
+    PersistentTaskStore<RangeDeletionTask> store(opCtx, NamespaceString::kRangeDeletionNamespace);
+    store.remove(opCtx, QUERY(RangeDeletionTask::kCollectionUuidFieldName << collectionUuid));
+}
+
+void markAsReadyRangeDeletionTaskOnRecipient(OperationContext* opCtx,
+                                             const ShardId& recipientId,
+                                             const UUID& migrationId) {
+    write_ops::Update updateOp(NamespaceString::kRangeDeletionNamespace);
+    auto queryFilter = BSON(RangeDeletionTask::kIdFieldName << migrationId);
+    auto updateModification = write_ops::UpdateModification(
+        BSON("$unset" << BSON(RangeDeletionTask::kPendingFieldName << "")));
+    write_ops::UpdateOpEntry updateEntry(queryFilter, updateModification);
+    updateEntry.setMulti(false);
+    updateEntry.setUpsert(false);
+    updateOp.setUpdates({updateEntry});
+
+    sendToRecipient(opCtx, recipientId, updateOp);
+}
+
+void markAsReadyRangeDeletionTaskLocally(OperationContext* opCtx, const UUID& migrationId) {
+    PersistentTaskStore<RangeDeletionTask> store(opCtx, NamespaceString::kRangeDeletionNamespace);
+    auto query = QUERY(RangeDeletionTask::kIdFieldName << migrationId);
+    auto update = BSON("$unset" << BSON(RangeDeletionTask::kPendingFieldName << ""));
+
+    store.update(opCtx, query, update);
+}
+}  // namespace migrationutil
 }  // namespace mongo
diff --git a/src/mongo/db/s/migration_util.h b/src/mongo/db/s/migration_util.h
index 6ba282e321b..f3119de0ef6 100644
--- a/src/mongo/db/s/migration_util.h
+++ b/src/mongo/db/s/migration_util.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2018-present MongoDB, Inc.
+ *    Copyright (C) 2019-present MongoDB, Inc.
  *
  *    This program is free software: you can redistribute it and/or modify
  *    it under the terms of the Server Side Public License, version 1,
@@ -29,6 +29,9 @@
 
 #pragma once
 
+#include "mongo/db/logical_session_id.h"
+#include "mongo/db/repl/optime.h"
+#include "mongo/db/s/migration_coordinator_document_gen.h"
 #include "mongo/db/s/persistent_task_store.h"
 #include "mongo/db/s/range_deletion_task_gen.h"
 #include "mongo/s/catalog/type_chunk.h"
@@ -81,6 +84,56 @@ void submitPendingDeletions(OperationContext* opCtx);
 // Asynchronously calls submitPendingDeletions using the fixed executor pool.
 void resubmitRangeDeletionsOnStepUp(ServiceContext* serviceContext);
 
-}  // namespace migrationutil
+/**
+ * Writes the migration coordinator document to config.migrationCoordinators and waits for majority
+ * write concern.
+ */
+void persistMigrationCoordinatorLocally(OperationContext* opCtx,
+                                        const MigrationCoordinatorDocument& migrationDoc);
+
+/**
+ * Writes the range deletion task document to config.rangeDeletions and waits for majority write
+ * concern.
+ */
+void persistRangeDeletionTaskLocally(OperationContext* opCtx,
+                                     const RangeDeletionTask& deletionTask);
+
+/**
+ * Deletes the range deletion task document with the specified id from config.rangeDeletions and
+ * waits for majority write concern.
+ */
+void deleteRangeDeletionTaskLocally(OperationContext* opCtx, const UUID& deletionTaskId);
+
+/**
+ * Deletes all range deletion task documents with the specified collection UUID from
+ * config.rangeDeletions and waits for majority write concern.
+ */
+void deleteRangeDeletionTasksForCollectionLocally(OperationContext* opCtx,
+                                                  const UUID& collectionUuid);
+
+/**
+ * Deletes the range deletion task document with the specified id from config.rangeDeletions on the
+ * specified shard and waits for majority write concern.
+ */
+void deleteRangeDeletionTaskOnRecipient(OperationContext* opCtx,
+                                        const ShardId& recipientId,
+                                        const UUID& migrationId);
 
+/**
+ * Removes the 'pending' flag from the range deletion task document with the specified id from
+ * config.rangeDeletions and waits for majority write concern. This marks the range as ready for
+ * deletion.
+ */
+void markAsReadyRangeDeletionTaskLocally(OperationContext* opCtx, const UUID& migrationId);
+
+
+/**
+ * Removes the 'pending' flag from the range deletion task document with the specified id from
+ * config.rangeDeletions on the specified shard and waits for majority write concern. This marks the
+ * range as ready for deletion.
+ */
+void markAsReadyRangeDeletionTaskOnRecipient(OperationContext* opCtx,
+                                             const ShardId& recipientId,
+                                             const UUID& migrationId);
+}  // namespace migrationutil
 }  // namespace mongo
diff --git a/src/mongo/db/s/migration_util_test.cpp b/src/mongo/db/s/migration_util_test.cpp
index 0496e64388c..f93471b2141 100644
--- a/src/mongo/db/s/migration_util_test.cpp
+++ b/src/mongo/db/s/migration_util_test.cpp
@@ -261,11 +261,12 @@ void addRangeToReceivingChunks(OperationContext* opCtx,
 }
 
 RangeDeletionTask createDeletionTask(NamespaceString nss, const UUID& uuid, int min, int max) {
-    RangeDeletionTask task{nss, uuid, CleanWhenEnum::kNow};
-
-    task.setRange(ChunkRange{BSON("_id" << min), BSON("_id" << max)});
-
-    return task;
+    return RangeDeletionTask(UUID::gen(),
+                             nss,
+                             uuid,
+                             ShardId("donorShard"),
+                             ChunkRange{BSON("_id" << min), BSON("_id" << max)},
+                             CleanWhenEnum::kDelayed);
 }
 
 // Test that overlappingRangeQuery() can handle the cases that we expect to encounter.
diff --git a/src/mongo/db/s/range_deletion_task.idl b/src/mongo/db/s/range_deletion_task.idl
index 9af29c5181d..1c265f2656a 100644
--- a/src/mongo/db/s/range_deletion_task.idl
+++ b/src/mongo/db/s/range_deletion_task.idl
@@ -31,19 +31,12 @@
 
 global:
     cpp_namespace: "mongo"
-    cpp_includes : "mongo/s/catalog/type_chunk.h"
 
 imports:
     - "mongo/idl/basic_types.idl"
-
-types:
-    chunkRangeType: 
-        description: "Represents the bounds of a chunk range. See ChunkRange for the semantics of
-                      the bounds."
-        bson_serialization_type: object
-        cpp_type: "mongo::ChunkRange"
-        serializer: "mongo::ChunkRange::toBSON"
-        deserializer: "mongo::ChunkRange::fromBSONThrowing"
+    - "mongo/s/sharding_types.idl"
+    - "mongo/db/logical_session_id.idl"
+    - "mongo/s/chunk_range.idl"
 
 enums:
     CleanWhen:
@@ -58,17 +51,22 @@ structs:
         description: "Represents a chunk range to be deleted by the range deleter."
         strict: false
         fields:
+            _id:
+                type: uuid
+                description: "A unique identifier for the migration."
+                cpp_name: id
             nss:
                 type: namespacestring
                 description: "The namespace of the collection that the chunk belongs to."
             collectionUuid:
                 type: uuid
                 description: "The UUID of the collection that the chunk belongs to."
+            donorShardId:
+                type: shard_id
+                description: "The shard from which the chunk was migrated."
             range:
-                type: chunkRangeType
-                description: "The range to be deleted. Needs to be optional since ChunkRange
-                              doesn't have a default constructor."
-                optional: true
+                type: chunk_range
+                description: "The range to be deleted."
             pending:
                 type: bool
                 description: "Flag that is present if the range is not yet ready for deletion"
diff --git a/src/mongo/s/catalog/type_chunk.h b/src/mongo/s/catalog/type_chunk.h
index 1905280392b..2e64e86d3dc 100644
--- a/src/mongo/s/catalog/type_chunk.h
+++ b/src/mongo/s/catalog/type_chunk.h
@@ -117,6 +117,13 @@ public:
     ChunkRange unionWith(ChunkRange const& other) const;
 
 private:
+    // For use with IDL parsing - limited to friend access only.
+    ChunkRange() = default;
+
+    // Make the IDL generated parser a friend
+    friend class RangeDeletionTask;
+    friend class MigrationCoordinatorDocument;
+
     BSONObj _minKey;
     BSONObj _maxKey;
 };
diff --git a/src/mongo/s/chunk_range.idl b/src/mongo/s/chunk_range.idl
new file mode 100644
index 00000000000..a60701bf952
--- /dev/null
+++ b/src/mongo/s/chunk_range.idl
@@ -0,0 +1,48 @@
+# Copyright (C) 2019-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+
+# IDL type for the ChunkRange class
+
+global:
+    cpp_namespace: "mongo"
+    cpp_includes:
+        - "mongo/s/catalog/type_chunk.h"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+types:
+    # Note that in order to use this type for a non-optional field, you must add the IDL struct as a
+    # friend class of ChunkRange so that it can access its default constructor.
+    chunk_range:
+        description: "Represents the bounds of a chunk range. See ChunkRange for the semantics of
+                      the bounds."
+        bson_serialization_type: object
+        cpp_type: "mongo::ChunkRange"
+        serializer: "mongo::ChunkRange::toBSON"
+        deserializer: "mongo::ChunkRange::fromBSONThrowing"
diff --git a/src/mongo/util/uuid.h b/src/mongo/util/uuid.h
index ae82c800264..5f7e27d35b9 100644
--- a/src/mongo/util/uuid.h
+++ b/src/mongo/util/uuid.h
@@ -76,6 +76,7 @@ class UUID {
     friend class LogicalSessionToClient;
     friend class LogicalSessionIdToClient;
     friend class LogicalSessionFromClient;
+    friend class MigrationCoordinatorDocument;
     friend class RangeDeletionTask;
     friend class ResolvedKeyId;
     friend class repl::CollectionInfo;