SERVER-37979 Add writing utilities to the index build interface

1 files changed, 173 insertions, 0 deletions

diff --git a/src/mongo/db/index_build_entry_helpers.h b/src/mongo/db/index_build_entry_helpers.h
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+/**
+ *    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 <vector>
+
+namespace mongo {
+
+class IndexBuildEntry;
+class CommitQuorumOptions;
+class OperationContext;
+class Status;
+template <typename T>
+class StatusWith;
+class UUID;
+struct HostAndPort;
+
+/**
+ * Format of IndexBuildEntry:
+ * {
+ *		_id : indexBuildUUID,
+ *		collectionUUID : <UUID>,
+ *		commitQuorum : <BSON>,
+ *		indexes : [<index_name1>, <index_name2>, ...],
+ *		commitReadyMembers : [
+ *			<hostAndPort1>,
+ *			<hostAndPort2>,
+ *			...
+ *		]
+ *	}
+ */
+
+namespace indexbuildentryhelpers {
+
+/**
+ * Creates the "config.system.indexBuilds" collection if it does not already exist.
+ * This is the collection where the IndexBuildEntries will be stored on disk for active index
+ * builds.
+ *
+ * The collection should exist before calling any other helper functions to prevent them from
+ * failing.
+ */
+void ensureIndexBuildEntriesNamespaceExists(OperationContext* opCtx);
+
+/**
+ * Writes the 'indexBuildEntry' to the disk.
+ *
+ * An IndexBuildEntry should be stored on the disk during the duration of the index build process
+ * for the 'indexBuildEntry'.
+ *
+ * Returns 'DuplicateKey' error code if a document already exists on the disk with the same
+ * 'indexBuildUUID'.
+ */
+Status addIndexBuildEntry(OperationContext* opCtx, IndexBuildEntry indexBuildEntry);
+
+/**
+ * Removes the IndexBuildEntry from the disk.
+ *
+ * An IndexBuildEntry should be removed from the disk when the index build either succeeds or fails
+ * for the given 'indexBuildUUID'.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+Status removeIndexBuildEntry(OperationContext* opCtx, UUID indexBuildUUID);
+
+/**
+ * Returns the IndexBuildEntry matching the document with 'indexBuildUUID' from the disk if it
+ * exists.
+ *
+ * If the stored IndexBuildEntry on disk contains invalid BSON, the 'InvalidBSON' error code is
+ * returned.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+StatusWith<IndexBuildEntry> getIndexBuildEntry(OperationContext* opCtx, UUID indexBuildUUID);
+
+/**
+ * Returns a vector of matching IndexBuildEntries matching the documents with 'collectionUUID'
+ * from disk.
+ *
+ * Can be used to get all the unfinished index builds on the collection if the indexBuildUUID is
+ * unknown.
+ */
+StatusWith<std::vector<IndexBuildEntry>> getIndexBuildEntries(OperationContext* opCtx,
+                                                              UUID collectionUUID);
+
+/**
+ * Returns the 'commitQuorum' matching the document with 'indexBuildUUID' from disk if it
+ * exists.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+StatusWith<CommitQuorumOptions> getCommitQuorum(OperationContext* opCtx, UUID indexBuildUUID);
+
+/**
+ * Sets the documents 'commitQuorum' field matching the document with 'indexBuildUUID'.
+ *
+ * Since the commit quorum is configurable until the index build is committed, this should be called
+ * whenever the commit quorum is changed.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+Status setCommitQuorum(OperationContext* opCtx,
+                       UUID indexBuildUUID,
+                       CommitQuorumOptions commitQuorumOptions);
+
+/**
+ * Adds 'hostAndPort' to the 'commitReadyMembers' field for the document with 'indexBuildUUID'.
+ * If the 'hostAndPort' is already in the 'commitReadyMembers' field, nothing is done.
+ *
+ * When a replica set member is ready to commit the index build, we need to record this.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+Status addCommitReadyMember(OperationContext* opCtx, UUID indexBuildUUID, HostAndPort hostAndPort);
+
+/**
+ * Removes 'hostAndPort' from the 'commitReadyMembers' field for the document with
+ * 'indexBuildUUID' if it exists.
+ *
+ * If a replica set member is removed during a reconfig and it was a commit ready member, we need to
+ * remove its entry from the 'commitReadyMembers' field.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+Status removeCommitReadyMember(OperationContext* opCtx,
+                               UUID indexBuildUUID,
+                               HostAndPort hostAndPort);
+
+/**
+ * Returns a vector of HostAndPorts of all the 'commitReadyMembers' for the document with
+ * 'indexBuildUUID'.
+ *
+ * Returns 'NoMatchingDocument' error code if no document with 'indexBuildUUID' is found.
+ */
+StatusWith<std::vector<HostAndPort>> getCommitReadyMembers(OperationContext* opCtx,
+                                                           UUID indexBuildUUID);
+
+/**
+ * Truncates all the documents in the "config.system.indexBuilds" collection.
+ * Can be used during recovery to remove unfinished index builds to restart them.
+ */
+Status clearAllIndexBuildEntries(OperationContext* opCtx);
+
+}  // namespace indexbuildentryhelpers
+}  // namespace mongo