foundationdb/fdbclient/BackupContainerFileSystem.h

192 lines
9.4 KiB
C++

/*
* BackupContainerFileSystem.h
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef FDBCLIENT_BACKUP_CONTAINER_FILESYSTEM_H
#define FDBCLIENT_BACKUP_CONTAINER_FILESYSTEM_H
#pragma once
#include "fdbclient/BackupContainer.h"
#include "fdbclient/FDBTypes.h"
#include "flow/Trace.h"
#include "fdbclient/BackupContainer.h"
/* BackupContainerFileSystem implements a backup container which stores files in a nested folder structure.
* Inheritors must only defined methods for writing, reading, deleting, sizing, and listing files.
*
* Snapshot manifests (a complete set of files constituting a database snapshot for the backup's target ranges)
* are stored as JSON files at paths like
* /snapshots/snapshot,minVersion,maxVersion,totalBytes
*
* Key range files for snapshots are stored at paths like
* /kvranges/snapshot,startVersion/N/range,version,uid,blockSize
* where startVersion is the version at which the backup snapshot execution began and N is a number
* that is increased as key range files are generated over time (at varying rates) such that there
* are around 5,000 key range files in each folder.
*
* Note that startVersion will NOT correspond to the minVersion of a snapshot manifest because
* snapshot manifest min/max versions are based on the actual contained data and the first data
* file written will be after the start version of the snapshot's execution.
*
* Log files are at file paths like
* /plogs/.../log,startVersion,endVersion,UID,tagID-of-N,blocksize
* /logs/.../log,startVersion,endVersion,UID,blockSize
* where ... is a multi level path which sorts lexically into version order and results in approximately 1
* unique folder per day containing about 5,000 files. Logs after FDB 6.3 are stored in "plogs"
* directory and are partitioned according to tagIDs (0, 1, 2, ...) and the total number partitions is N.
* Old backup logs FDB 6.2 and earlier are stored in "logs" directory and are not partitioned.
* After FDB 6.3, users can choose to use the new partitioned logs or old logs.
*
*
* BACKWARD COMPATIBILITY
*
* Prior to FDB version 6.0.16, key range files were stored using a different folder scheme. Newer versions
* still support this scheme for all restore and backup management operations but key range files generated
* by backup using version 6.0.16 or later use the scheme describe above.
*
* The old format stored key range files at paths like
* /ranges/.../range,version,uid,blockSize
* where ... is a multi level path with sorts lexically into version order and results in up to approximately
* 900 unique folders per day. The number of files per folder depends on the configured snapshot rate and
* database size and will vary from 1 to around 5,000.
*/
class BackupContainerFileSystem : public IBackupContainer {
public:
void addref() override = 0;
void delref() override = 0;
BackupContainerFileSystem() {}
~BackupContainerFileSystem() override {}
// Create the container
Future<Void> create() override = 0;
Future<bool> exists() override = 0;
// Get a list of fileNames and their sizes in the container under the given path
// Although not required, an implementation can avoid traversing unwanted subfolders
// by calling folderPathFilter(absoluteFolderPath) and checking for a false return value.
using FilesAndSizesT = std::vector<std::pair<std::string, int64_t>>;
virtual Future<FilesAndSizesT> listFiles(const std::string& path = "",
std::function<bool(std::string const&)> folderPathFilter = nullptr) = 0;
// Open a file for read by fileName
Future<Reference<IAsyncFile>> readFile(const std::string& fileName) override = 0;
// Open a file for write by fileName
virtual Future<Reference<IBackupFile>> writeFile(const std::string& fileName) = 0;
// Delete a file
virtual Future<Void> deleteFile(const std::string& fileName) = 0;
// Delete entire container. During the process, if pNumDeleted is not null it will be
// updated with the count of deleted files so that progress can be seen.
Future<Void> deleteContainer(int* pNumDeleted) override = 0;
Future<Reference<IBackupFile>> writeLogFile(Version beginVersion, Version endVersion, int blockSize) final;
Future<Reference<IBackupFile>> writeTaggedLogFile(Version beginVersion,
Version endVersion,
int blockSize,
uint16_t tagId,
int totalTags) final;
Future<Reference<IBackupFile>> writeRangeFile(Version snapshotBeginVersion,
int snapshotFileCount,
Version fileVersion,
int blockSize) override;
Future<std::pair<std::vector<RangeFile>, std::map<std::string, KeyRange>>> readKeyspaceSnapshot(
KeyspaceSnapshotFile snapshot);
Future<Void> writeKeyspaceSnapshotFile(const std::vector<std::string>& fileNames,
const std::vector<std::pair<Key, Key>>& beginEndKeys,
int64_t totalBytes) final;
// List log files, unsorted, which contain data at any version >= beginVersion and <= targetVersion.
// "partitioned" flag indicates if new partitioned mutation logs or old logs should be listed.
Future<std::vector<LogFile>> listLogFiles(Version beginVersion, Version targetVersion, bool partitioned);
// List range files, unsorted, which contain data at or between beginVersion and endVersion
// Note: The contents of each top level snapshot.N folder do not necessarily constitute a valid snapshot
// and therefore listing files is not how RestoreSets are obtained.
// Note: Snapshots partially written using FDB versions prior to 6.0.16 will have some range files stored
// using the old folder scheme read by old_listRangeFiles
Future<std::vector<RangeFile>> listRangeFiles(Version beginVersion, Version endVersion);
// List snapshots which have been fully written, in sorted beginVersion order, which start before end and finish on
// or after begin
Future<std::vector<KeyspaceSnapshotFile>> listKeyspaceSnapshots(Version begin = 0,
Version end = std::numeric_limits<Version>::max());
Future<BackupFileList> dumpFileList(Version begin, Version end) override;
// Uses the virtual methods to describe the backup contents
Future<BackupDescription> describeBackup(bool deepScan, Version logStartVersionOverride) final;
// Delete all data up to (but not including endVersion)
Future<Void> expireData(Version expireEndVersion,
bool force,
ExpireProgress* progress,
Version restorableBeginVersion) final;
Future<KeyRange> getSnapshotFileKeyRange(const RangeFile& file) final;
Future<Optional<RestorableFileSet>> getRestoreSet(Version targetVersion,
VectorRef<KeyRangeRef> keyRangesFilter,
bool logsOnly,
Version beginVersion) final;
private:
struct VersionProperty {
VersionProperty(Reference<BackupContainerFileSystem> bc, const std::string& name)
: bc(bc), path("properties/" + name) {}
Reference<BackupContainerFileSystem> bc;
std::string path;
Future<Optional<Version>> get();
Future<Void> set(Version v);
Future<Void> clear();
};
// To avoid the need to scan the underyling filesystem in many cases, some important version boundaries are stored
// in named files. These versions also indicate what version ranges are known to be deleted or partially deleted.
//
// The values below describe version ranges as follows:
// 0 - expiredEndVersion All files in this range have been deleted
// expiredEndVersion - unreliableEndVersion Some files in this range may have been deleted.
//
// logBeginVersion - logEnd Log files are contiguous in this range and have NOT been deleted by
// fdbbackup logEnd - infinity Files in this range may or may not exist yet
//
VersionProperty logBeginVersion();
VersionProperty logEndVersion();
VersionProperty expiredEndVersion();
VersionProperty unreliableEndVersion();
VersionProperty logType();
// List range files, unsorted, which contain data at or between beginVersion and endVersion
// NOTE: This reads the range file folder schema from FDB 6.0.15 and earlier and is provided for backward
// compatibility
Future<std::vector<RangeFile>> old_listRangeFiles(Version beginVersion, Version endVersion);
friend class BackupContainerFileSystemImpl;
};
#endif