SERVER-49180 Make the donor's dataSync function reserve an OpTime at which to do the "start blocking" write

9 files changed, 225 insertions, 0 deletions

diff --git a/src/mongo/db/catalog/collection.h b/src/mongo/db/catalog/collection.h
index c05226fb4ce..337e474e1dd 100644
--- a/src/mongo/db/catalog/collection.h
+++ b/src/mongo/db/catalog/collection.h
@@ -95,6 +95,9 @@ struct CollectionUpdateArgs {
 
     StoreDocOption storeDocOption = StoreDocOption::None;
     bool preImageRecordingEnabledForCollection = false;
+
+    // Set if an OpTime was reserved for the update ahead of time.
+    boost::optional<OplogSlot> oplogSlot = boost::none;
 };
 
 /**
diff --git a/src/mongo/db/namespace_string.cpp b/src/mongo/db/namespace_string.cpp
index 9c01465712a..92c46ef6652 100644
--- a/src/mongo/db/namespace_string.cpp
+++ b/src/mongo/db/namespace_string.cpp
@@ -69,6 +69,9 @@ const NamespaceString NamespaceString::kTransactionCoordinatorsNamespace(
 const NamespaceString NamespaceString::kMigrationCoordinatorsNamespace(NamespaceString::kConfigDb,
                                                                        "migrationCoordinators");
 
+const NamespaceString NamespaceString::kMigrationDonorsNamespace(NamespaceString::kConfigDb,
+                                                                 "migrationDonors");
+
 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 3b15575292b..c80d9eb3bb1 100644
--- a/src/mongo/db/namespace_string.h
+++ b/src/mongo/db/namespace_string.h
@@ -106,6 +106,9 @@ public:
     // Namespace for storing the persisted state of migration coordinators.
     static const NamespaceString kMigrationCoordinatorsNamespace;
 
+    // Namespace for storing the persisted state of tenant migration donors.
+    static const NamespaceString kMigrationDonorsNamespace;
+
     // Namespace for replica set configuration settings.
     static const NamespaceString kSystemReplSetNamespace;
 
diff --git a/src/mongo/db/op_observer_impl.cpp b/src/mongo/db/op_observer_impl.cpp
index 92710526e59..f051925c4b4 100644
--- a/src/mongo/db/op_observer_impl.cpp
+++ b/src/mongo/db/op_observer_impl.cpp
@@ -192,6 +192,9 @@ OpTimeBundle replLogUpdate(OperationContext* opCtx, const OplogUpdateEntryArgs&
     oplogEntry.setFromMigrateIfTrue(args.updateArgs.fromMigrate);
     // oplogLink could have been changed to include pre/postImageOpTime by the previous no-op write.
     repl::appendOplogEntryChainInfo(opCtx, &oplogEntry, &oplogLink, args.updateArgs.stmtId);
+    if (args.updateArgs.oplogSlot) {
+        oplogEntry.setOpTime(*args.updateArgs.oplogSlot);
+    }
     opTimes.writeOpTime = logOperation(opCtx, &oplogEntry);
     opTimes.wallClockTime = oplogEntry.getWallClockTime();
     return opTimes;
diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 2f89d244e6b..21d7b496a20 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -1181,9 +1181,11 @@ env.Library(
 env.Library(
     target="serveronly_repl",
     source=[
+        'migrating_tenant_donor_util.cpp',
         'noop_writer.cpp',
         "replication_coordinator_external_state_impl.cpp",
         "sync_source_feedback.cpp",
+        env.Idlc('migrate_tenant_state_machine.idl')[0],
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
diff --git a/src/mongo/db/repl/migrate_tenant_state_machine.idl b/src/mongo/db/repl/migrate_tenant_state_machine.idl
new file mode 100644
index 00000000000..ba9cdba45b3
--- /dev/null
+++ b/src/mongo/db/repl/migrate_tenant_state_machine.idl
@@ -0,0 +1,63 @@
+# Copyright (C) 2020-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.
+#
+global:
+    cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+enums:
+    TenantMigrationDonorState:
+        description: "The state of an in-progress tenant migration."
+        type: string
+        values:
+            kDataSync: "data sync"
+            kBlocking: "blocking"
+            kCommitted: "committed"
+            kAborted: "aborted"
+
+structs:
+    tenantMigrationDonorDocument:
+        description: "Represents an in-progress tenant migration on the migration donor."
+        strict: true
+        fields:
+            _id:
+                type: objectid
+                description: "A unique identifier for the document."
+                cpp_name: id
+            databasePrefix:
+                type: string
+                description: "The database prefix for the migration."
+            blockTimestamp:
+                type: timestamp
+                description: "The timestamp at which writes and causal reads against the databases
+                              being migrated should start blocking."
+                optional: true
+            state:
+                type: TenantMigrationDonorState
+                description: "The state of the tenant migration."
diff --git a/src/mongo/db/repl/migrating_tenant_donor_util.cpp b/src/mongo/db/repl/migrating_tenant_donor_util.cpp
new file mode 100644
index 00000000000..5aac1584f02
--- /dev/null
+++ b/src/mongo/db/repl/migrating_tenant_donor_util.cpp
@@ -0,0 +1,100 @@
+/**
+ *    Copyright (C) 2020-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.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/repl/migrating_tenant_donor_util.h"
+
+#include "mongo/db/concurrency/write_conflict_exception.h"
+#include "mongo/db/db_raii.h"
+#include "mongo/db/dbhelpers.h"
+
+namespace mongo {
+
+namespace migrating_tenant_donor_util {
+void dataSync(OperationContext* opCtx, const TenantMigrationDonorDocument& originalDoc) {
+    // Send recipientSyncData.
+
+    // Call startBlockingWrites.
+
+    // Update the on-disk state of the migration to "blocking" state.
+    invariant(originalDoc.getState() == TenantMigrationDonorStateEnum::kDataSync);
+
+    uassertStatusOK(writeConflictRetry(
+        opCtx,
+        "doStartBlockingWrite",
+        NamespaceString::kMigrationDonorsNamespace.ns(),
+        [&]() -> Status {
+            AutoGetCollection autoCollection(
+                opCtx, NamespaceString::kMigrationDonorsNamespace, MODE_IX);
+            Collection* collection = autoCollection.getCollection();
+
+            if (!collection) {
+                return Status(ErrorCodes::NamespaceNotFound,
+                              str::stream() << NamespaceString::kMigrationDonorsNamespace.ns()
+                                            << " does not exist");
+            }
+
+            WriteUnitOfWork wuow(opCtx);
+
+            const auto originalRecordId =
+                Helpers::findOne(opCtx, collection, originalDoc.toBSON(), false /* requireIndex */);
+            invariant(!originalRecordId.isNull());
+
+            // Reserve an opTime for the write and use it as the blockTimestamp for the migration.
+            auto oplogSlot = repl::LocalOplogInfo::get(opCtx)->getNextOpTimes(opCtx, 1U)[0];
+
+            TenantMigrationDonorDocument updatedDoc;
+            updatedDoc.setId(originalDoc.getId());
+            updatedDoc.setDatabasePrefix(originalDoc.getDatabasePrefix());
+            updatedDoc.setState(TenantMigrationDonorStateEnum::kBlocking);
+            updatedDoc.setBlockTimestamp(oplogSlot.getTimestamp());
+
+            CollectionUpdateArgs args;
+            args.update = updatedDoc.toBSON();
+            args.criteria = BSON("_id" << originalDoc.getId());
+            args.oplogSlot = oplogSlot;
+
+            collection->updateDocument(
+                opCtx,
+                originalRecordId,
+                Snapshotted<BSONObj>(opCtx->recoveryUnit()->getSnapshotId(), originalDoc.toBSON()),
+                updatedDoc.toBSON(),
+                false,
+                nullptr /* OpDebug* */,
+                &args);
+
+            wuow.commit();
+
+            return Status::OK();
+        }));
+}
+}  // namespace migrating_tenant_donor_util
+
+}  // namespace mongo
diff --git a/src/mongo/db/repl/migrating_tenant_donor_util.h b/src/mongo/db/repl/migrating_tenant_donor_util.h
new file mode 100644
index 00000000000..14f93fd2bb5
--- /dev/null
+++ b/src/mongo/db/repl/migrating_tenant_donor_util.h
@@ -0,0 +1,47 @@
+/**
+ *    Copyright (C) 2020-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/operation_context.h"
+#include "mongo/db/repl/migrate_tenant_state_machine_gen.h"
+
+namespace mongo {
+
+namespace migrating_tenant_donor_util {
+
+/**
+ * Sends recipientSyncData to the recipient until success and starts blocking writes and causal
+ * reads.
+ */
+void dataSync(OperationContext* opCtx, const TenantMigrationDonorDocument& donorDoc);
+
+}  // namespace migrating_tenant_donor_util
+
+}  // namespace mongo
diff --git a/src/mongo/util/uuid.h b/src/mongo/util/uuid.h
index a9c087f7777..867f405dfcb 100644
--- a/src/mongo/util/uuid.h
+++ b/src/mongo/util/uuid.h
@@ -87,6 +87,7 @@ class UUID {
     friend class repl::InitialSyncIdDocument;
     friend class ResumeTokenInternal;
     friend class ShardCollectionTypeBase;
+    friend class TenantMigrationDonorDocument;
     friend class VoteCommitIndexBuild;
 
 public: