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rocksdb/utilities/backupable/backupable_db.cc
Peter Dillinger 3ffb3baa0b Add (Live)FileStorageInfo API (#8968) 
Summary:
New classes FileStorageInfo and LiveFileStorageInfo and
'experimental' function DB::GetLiveFilesStorageInfo, which is intended
to largely replace several fragmented DB functions needed to create
checkpoints and backups.

This function is now used to create checkpoints and backups, because
it fixes many (probably not all) of the prior complexities of checkpoint
not having atomic access to DB metadata. This also ensures strong
functional test coverage of the new API. Specifically, much of the old
CheckpointImpl::CreateCustomCheckpoint has been migrated to and
updated in DBImpl::GetLiveFilesStorageInfo, with the former now
calling the latter.

Also, the class FileStorageInfo in metadata.h compatibly replaces
BackupFileInfo and serves as a new base class for SstFileMetaData.
Some old fields of SstFileMetaData are still provided (for now) but
deprecated.

Although FileStorageInfo::directory is accurate when using db_paths
and/or cf_paths, these have never been supported by Checkpoint
nor BackupEngine and still are not. This change does now detect
these cases and return NotSupported when appropriate. (More work
needed for support.)

Somehow this change broke ProgressCallbackDuringBackup, but
the progress_callback logic was dubious to begin with because it
would call the callback based on copy buffer size, not size actually
copied. Logic and test updated to track size actually copied
per-thread.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8968

Test Plan:
tests updated.
DB::GetLiveFilesStorageInfo mostly tested by use in CheckpointImpl.
DBTest.SnapshotFiles updated to also test GetLiveFilesStorageInfo,
including reading the data after DB close.
Added CheckpointTest.CheckpointWithDbPath (NotSupported).

Reviewed By: siying

Differential Revision: D31242045

Pulled By: pdillinger

fbshipit-source-id: b183d1ce9799e220daaefd6b3b5365d98de676c0
2021-10-16 10:04:32 -07:00

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef ROCKSDB_LITE
#include <algorithm>
#include <atomic>
#include <cinttypes>
#include <cstdlib>
#include <functional>
#include <future>
#include <limits>
#include <map>
#include <mutex>
#include <sstream>
#include <string>
#include <thread>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "env/composite_env_wrapper.h"
#include "env/fs_readonly.h"
#include "env/fs_remap.h"
#include "file/filename.h"
#include "file/line_file_reader.h"
#include "file/sequence_file_reader.h"
#include "file/writable_file_writer.h"
#include "logging/logging.h"
#include "monitoring/iostats_context_imp.h"
#include "port/port.h"
#include "rocksdb/rate_limiter.h"
#include "rocksdb/transaction_log.h"
#include "table/sst_file_dumper.h"
#include "test_util/sync_point.h"
#include "util/cast_util.h"
#include "util/channel.h"
#include "util/coding.h"
#include "util/crc32c.h"
#include "util/string_util.h"
#include "utilities/backupable/backupable_db_impl.h"
#include "utilities/checkpoint/checkpoint_impl.h"
namespace ROCKSDB_NAMESPACE {
namespace {
using ShareFilesNaming = BackupEngineOptions::ShareFilesNaming;
constexpr BackupID kLatestBackupIDMarker = static_cast<BackupID>(-2);
inline uint32_t ChecksumHexToInt32(const std::string& checksum_hex) {
std::string checksum_str;
Slice(checksum_hex).DecodeHex(&checksum_str);
return EndianSwapValue(DecodeFixed32(checksum_str.c_str()));
}
inline std::string ChecksumStrToHex(const std::string& checksum_str) {
return Slice(checksum_str).ToString(true);
}
inline std::string ChecksumInt32ToHex(const uint32_t& checksum_value) {
std::string checksum_str;
PutFixed32(&checksum_str, EndianSwapValue(checksum_value));
return ChecksumStrToHex(checksum_str);
}
const std::string kPrivateDirName = "private";
const std::string kMetaDirName = "meta";
const std::string kSharedDirName = "shared";
const std::string kSharedChecksumDirName = "shared_checksum";
const std::string kPrivateDirSlash = kPrivateDirName + "/";
const std::string kMetaDirSlash = kMetaDirName + "/";
const std::string kSharedDirSlash = kSharedDirName + "/";
const std::string kSharedChecksumDirSlash = kSharedChecksumDirName + "/";
} // namespace
void BackupStatistics::IncrementNumberSuccessBackup() {
number_success_backup++;
}
void BackupStatistics::IncrementNumberFailBackup() {
number_fail_backup++;
}
uint32_t BackupStatistics::GetNumberSuccessBackup() const {
return number_success_backup;
}
uint32_t BackupStatistics::GetNumberFailBackup() const {
return number_fail_backup;
}
std::string BackupStatistics::ToString() const {
char result[50];
snprintf(result, sizeof(result), "# success backup: %u, # fail backup: %u",
GetNumberSuccessBackup(), GetNumberFailBackup());
return result;
}
void BackupEngineOptions::Dump(Logger* logger) const {
ROCKS_LOG_INFO(logger, " Options.backup_dir: %s",
backup_dir.c_str());
ROCKS_LOG_INFO(logger, " Options.backup_env: %p", backup_env);
ROCKS_LOG_INFO(logger, " Options.share_table_files: %d",
static_cast<int>(share_table_files));
ROCKS_LOG_INFO(logger, " Options.info_log: %p", info_log);
ROCKS_LOG_INFO(logger, " Options.sync: %d",
static_cast<int>(sync));
ROCKS_LOG_INFO(logger, " Options.destroy_old_data: %d",
static_cast<int>(destroy_old_data));
ROCKS_LOG_INFO(logger, " Options.backup_log_files: %d",
static_cast<int>(backup_log_files));
ROCKS_LOG_INFO(logger, " Options.backup_rate_limit: %" PRIu64,
backup_rate_limit);
ROCKS_LOG_INFO(logger, " Options.restore_rate_limit: %" PRIu64,
restore_rate_limit);
ROCKS_LOG_INFO(logger, "Options.max_background_operations: %d",
max_background_operations);
}
// -------- BackupEngineImpl class ---------
class BackupEngineImpl {
public:
BackupEngineImpl(const BackupEngineOptions& options, Env* db_env,
bool read_only = false);
~BackupEngineImpl();
IOStatus CreateNewBackupWithMetadata(const CreateBackupOptions& options,
DB* db, const std::string& app_metadata,
BackupID* new_backup_id_ptr);
IOStatus PurgeOldBackups(uint32_t num_backups_to_keep);
IOStatus DeleteBackup(BackupID backup_id);
void StopBackup() { stop_backup_.store(true, std::memory_order_release); }
IOStatus GarbageCollect();
// The returned BackupInfos are in chronological order, which means the
// latest backup comes last.
void GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const;
Status GetBackupInfo(BackupID backup_id, BackupInfo* backup_info,
bool include_file_details = false) const;
void GetCorruptedBackups(std::vector<BackupID>* corrupt_backup_ids) const;
IOStatus RestoreDBFromBackup(const RestoreOptions& options,
BackupID backup_id, const std::string& db_dir,
const std::string& wal_dir) const;
IOStatus RestoreDBFromLatestBackup(const RestoreOptions& options,
const std::string& db_dir,
const std::string& wal_dir) const {
// Note: don't read latest_valid_backup_id_ outside of lock
return RestoreDBFromBackup(options, kLatestBackupIDMarker, db_dir, wal_dir);
}
IOStatus VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) const;
IOStatus Initialize();
ShareFilesNaming GetNamingNoFlags() const {
return options_.share_files_with_checksum_naming &
BackupEngineOptions::kMaskNoNamingFlags;
}
ShareFilesNaming GetNamingFlags() const {
return options_.share_files_with_checksum_naming &
BackupEngineOptions::kMaskNamingFlags;
}
private:
void DeleteChildren(const std::string& dir,
uint32_t file_type_filter = 0) const;
IOStatus DeleteBackupNoGC(BackupID backup_id);
// Extends the "result" map with pathname->size mappings for the contents of
// "dir" in "env". Pathnames are prefixed with "dir".
IOStatus ReadChildFileCurrentSizes(
const std::string& dir, const std::shared_ptr<FileSystem>&,
std::unordered_map<std::string, uint64_t>* result) const;
struct FileInfo {
FileInfo(const std::string& fname, uint64_t sz, const std::string& checksum,
const std::string& id = "", const std::string& sid = "")
: refs(0),
filename(fname),
size(sz),
checksum_hex(checksum),
db_id(id),
db_session_id(sid) {}
FileInfo(const FileInfo&) = delete;
FileInfo& operator=(const FileInfo&) = delete;
int refs;
const std::string filename;
const uint64_t size;
// crc32c checksum as hex. empty == unknown / unavailable
std::string checksum_hex;
// DB identities
// db_id is obtained for potential usage in the future but not used
// currently
const std::string db_id;
// db_session_id appears in the backup SST filename if the table naming
// option is kUseDbSessionId
const std::string db_session_id;
std::string GetDbFileName() {
std::string rv;
// extract the filename part
size_t slash = filename.find_last_of('/');
// file will either be shared/<file>, shared_checksum/<file_crc32c_size>,
// shared_checksum/<file_session>, shared_checksum/<file_crc32c_session>,
// or private/<number>/<file>
assert(slash != std::string::npos);
rv = filename.substr(slash + 1);
// if the file was in shared_checksum, extract the real file name
// in this case the file is <number>_<checksum>_<size>.<type>,
// <number>_<session>.<type>, or <number>_<checksum>_<session>.<type>
if (filename.substr(0, slash) == kSharedChecksumDirName) {
rv = GetFileFromChecksumFile(rv);
}
return rv;
}
};
static inline std::string WithoutTrailingSlash(const std::string& path) {
if (path.empty() || path.back() != '/') {
return path;
} else {
return path.substr(path.size() - 1);
}
}
static inline std::string WithTrailingSlash(const std::string& path) {
if (path.empty() || path.back() != '/') {
return path + '/';
} else {
return path;
}
}
// A filesystem wrapper that makes shared backup files appear to be in the
// private backup directory (dst_dir), so that the private backup dir can
// be opened as a read-only DB.
class RemapSharedFileSystem : public RemapFileSystem {
public:
RemapSharedFileSystem(const std::shared_ptr<FileSystem>& base,
const std::string& dst_dir,
const std::string& src_base_dir,
const std::vector<std::shared_ptr<FileInfo>>& files)
: RemapFileSystem(base),
dst_dir_(WithoutTrailingSlash(dst_dir)),
dst_dir_slash_(WithTrailingSlash(dst_dir)),
src_base_dir_(WithTrailingSlash(src_base_dir)) {
for (auto& info : files) {
if (!StartsWith(info->filename, kPrivateDirSlash)) {
assert(StartsWith(info->filename, kSharedDirSlash) ||
StartsWith(info->filename, kSharedChecksumDirSlash));
remaps_[info->GetDbFileName()] = info;
}
}
}
const char* Name() const override {
return "BackupEngineImpl::RemapSharedFileSystem";
}
// Sometimes a directory listing is required in opening a DB
IOStatus GetChildren(const std::string& dir, const IOOptions& options,
std::vector<std::string>* result,
IODebugContext* dbg) override {
IOStatus s = RemapFileSystem::GetChildren(dir, options, result, dbg);
if (s.ok() && (dir == dst_dir_ || dir == dst_dir_slash_)) {
// Assume remapped files exist
for (auto& r : remaps_) {
result->push_back(r.first);
}
}
return s;
}
// Sometimes a directory listing is required in opening a DB
IOStatus GetChildrenFileAttributes(const std::string& dir,
const IOOptions& options,
std::vector<FileAttributes>* result,
IODebugContext* dbg) override {
IOStatus s =
RemapFileSystem::GetChildrenFileAttributes(dir, options, result, dbg);
if (s.ok() && (dir == dst_dir_ || dir == dst_dir_slash_)) {
// Assume remapped files exist with recorded size
for (auto& r : remaps_) {
result->emplace_back(); // clean up with C++20
FileAttributes& attr = result->back();
attr.name = r.first;
attr.size_bytes = r.second->size;
}
}
return s;
}
protected:
// When a file in dst_dir is requested, see if we need to remap to shared
// file path.
std::pair<IOStatus, std::string> EncodePath(
const std::string& path) override {
if (path.empty() || path[0] != '/') {
return {IOStatus::InvalidArgument(path, "Not an absolute path"), ""};
}
std::pair<IOStatus, std::string> rv{IOStatus(), path};
if (StartsWith(path, dst_dir_slash_)) {
std::string relative = path.substr(dst_dir_slash_.size());
auto it = remaps_.find(relative);
if (it != remaps_.end()) {
rv.second = src_base_dir_ + it->second->filename;
}
}
return rv;
}
private:
// Absolute path to a directory that some extra files will be mapped into.
const std::string dst_dir_;
// Includes a trailing slash.
const std::string dst_dir_slash_;
// Absolute path to a directory containing some files to be mapped into
// dst_dir_. Includes a trailing slash.
const std::string src_base_dir_;
// If remaps_[x] exists, attempt to read dst_dir_ / x should instead read
// src_base_dir_ / remaps_[x]->filename. FileInfo is used to maximize
// sharing with other backup data in memory.
std::unordered_map<std::string, std::shared_ptr<FileInfo>> remaps_;
};
class BackupMeta {
public:
BackupMeta(
const std::string& meta_filename, const std::string& meta_tmp_filename,
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos,
Env* env, const std::shared_ptr<FileSystem>& fs)
: timestamp_(0),
sequence_number_(0),
size_(0),
meta_filename_(meta_filename),
meta_tmp_filename_(meta_tmp_filename),
file_infos_(file_infos),
env_(env),
fs_(fs) {}
BackupMeta(const BackupMeta&) = delete;
BackupMeta& operator=(const BackupMeta&) = delete;
~BackupMeta() {}
void RecordTimestamp() {
// Best effort
Status s = env_->GetCurrentTime(&timestamp_);
if (!s.ok()) {
timestamp_ = /* something clearly fabricated */ 1;
}
}
int64_t GetTimestamp() const {
return timestamp_;
}
uint64_t GetSize() const {
return size_;
}
uint32_t GetNumberFiles() const {
return static_cast<uint32_t>(files_.size());
}
void SetSequenceNumber(uint64_t sequence_number) {
sequence_number_ = sequence_number;
}
uint64_t GetSequenceNumber() const { return sequence_number_; }
const std::string& GetAppMetadata() const { return app_metadata_; }
void SetAppMetadata(const std::string& app_metadata) {
app_metadata_ = app_metadata;
}
IOStatus AddFile(std::shared_ptr<FileInfo> file_info);
IOStatus Delete(bool delete_meta = true);
bool Empty() const { return files_.empty(); }
std::shared_ptr<FileInfo> GetFile(const std::string& filename) const {
auto it = file_infos_->find(filename);
if (it == file_infos_->end())
return nullptr;
return it->second;
}
const std::vector<std::shared_ptr<FileInfo>>& GetFiles() const {
return files_;
}
// @param abs_path_to_size Pre-fetched file sizes (bytes).
IOStatus LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size,
RateLimiter* rate_limiter, Logger* info_log,
std::unordered_set<std::string>* reported_ignored_fields);
IOStatus StoreToFile(
bool sync, const TEST_FutureSchemaVersion2Options* test_future_options);
std::string GetInfoString() {
std::ostringstream ss;
ss << "Timestamp: " << timestamp_ << std::endl;
char human_size[16];
AppendHumanBytes(size_, human_size, sizeof(human_size));
ss << "Size: " << human_size << std::endl;
ss << "Files:" << std::endl;
for (const auto& file : files_) {
AppendHumanBytes(file->size, human_size, sizeof(human_size));
ss << file->filename << ", size " << human_size << ", refs "
<< file->refs << std::endl;
}
return ss.str();
}
const std::shared_ptr<Env>& GetEnvForOpen() const {
if (!env_for_open_) {
// Lazy initialize
// Find directories
std::string dst_dir = meta_filename_;
auto i = dst_dir.rfind(kMetaDirSlash);
assert(i != std::string::npos);
std::string src_base_dir = dst_dir.substr(0, i);
dst_dir.replace(i, kMetaDirSlash.size(), kPrivateDirSlash);
// Make the RemapSharedFileSystem
std::shared_ptr<FileSystem> remap_fs =
std::make_shared<RemapSharedFileSystem>(fs_, dst_dir, src_base_dir,
files_);
// Make it read-only for safety
remap_fs = std::make_shared<ReadOnlyFileSystem>(remap_fs);
// Make an Env wrapper
env_for_open_ = std::make_shared<CompositeEnvWrapper>(env_, remap_fs);
}
return env_for_open_;
}
private:
int64_t timestamp_;
// sequence number is only approximate, should not be used
// by clients
uint64_t sequence_number_;
uint64_t size_;
std::string app_metadata_;
std::string const meta_filename_;
std::string const meta_tmp_filename_;
// files with relative paths (without "/" prefix!!)
std::vector<std::shared_ptr<FileInfo>> files_;
std::unordered_map<std::string, std::shared_ptr<FileInfo>>* file_infos_;
Env* env_;
mutable std::shared_ptr<Env> env_for_open_;
std::shared_ptr<FileSystem> fs_;
IOOptions iooptions_ = IOOptions();
}; // BackupMeta
void SetBackupInfoFromBackupMeta(BackupID id, const BackupMeta& meta,
BackupInfo* backup_info,
bool include_file_details) const;
inline std::string GetAbsolutePath(
const std::string &relative_path = "") const {
assert(relative_path.size() == 0 || relative_path[0] != '/');
return options_.backup_dir + "/" + relative_path;
}
inline std::string GetPrivateFileRel(BackupID backup_id,
bool tmp = false,
const std::string& file = "") const {
assert(file.size() == 0 || file[0] != '/');
return kPrivateDirSlash + ROCKSDB_NAMESPACE::ToString(backup_id) +
(tmp ? ".tmp" : "") + "/" + file;
}
inline std::string GetSharedFileRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return kSharedDirSlash + std::string(tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline std::string GetSharedFileWithChecksumRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return kSharedChecksumDirSlash + std::string(tmp ? "." : "") + file +
(tmp ? ".tmp" : "");
}
inline bool UseLegacyNaming(const std::string& sid) const {
return GetNamingNoFlags() ==
BackupEngineOptions::kLegacyCrc32cAndFileSize ||
sid.empty();
}
inline std::string GetSharedFileWithChecksum(
const std::string& file, const std::string& checksum_hex,
const uint64_t file_size, const std::string& db_session_id) const {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
if (UseLegacyNaming(db_session_id)) {
assert(!checksum_hex.empty());
file_copy.insert(file_copy.find_last_of('.'),
"_" + ToString(ChecksumHexToInt32(checksum_hex)) + "_" +
ToString(file_size));
} else {
file_copy.insert(file_copy.find_last_of('.'), "_s" + db_session_id);
if (GetNamingFlags() & BackupEngineOptions::kFlagIncludeFileSize) {
file_copy.insert(file_copy.find_last_of('.'),
"_" + ToString(file_size));
}
}
return file_copy;
}
static inline std::string GetFileFromChecksumFile(const std::string& file) {
assert(file.size() == 0 || file[0] != '/');
std::string file_copy = file;
size_t first_underscore = file_copy.find_first_of('_');
return file_copy.erase(first_underscore,
file_copy.find_last_of('.') - first_underscore);
}
inline std::string GetBackupMetaFile(BackupID backup_id, bool tmp) const {
return GetAbsolutePath(kMetaDirName) + "/" + (tmp ? "." : "") +
ROCKSDB_NAMESPACE::ToString(backup_id) + (tmp ? ".tmp" : "");
}
// If size_limit == 0, there is no size limit, copy everything.
//
// Exactly one of src and contents must be non-empty.
//
// @param src If non-empty, the file is copied from this pathname.
// @param contents If non-empty, the file will be created with these contents.
IOStatus CopyOrCreateFile(const std::string& src, const std::string& dst,
const std::string& contents, uint64_t size_limit,
Env* src_env, Env* dst_env,
const EnvOptions& src_env_options, bool sync,
RateLimiter* rate_limiter,
std::function<void()> progress_callback,
uint64_t* bytes_toward_next_callback,
uint64_t* size, std::string* checksum_hex);
IOStatus ReadFileAndComputeChecksum(const std::string& src,
const std::shared_ptr<FileSystem>& src_fs,
const EnvOptions& src_env_options,
uint64_t size_limit,
std::string* checksum_hex) const;
// Obtain db_id and db_session_id from the table properties of file_path
Status GetFileDbIdentities(Env* src_env, const EnvOptions& src_env_options,
const std::string& file_path,
RateLimiter* rate_limiter, std::string* db_id,
std::string* db_session_id);
struct CopyOrCreateResult {
~CopyOrCreateResult() {
// The Status needs to be ignored here for two reasons.
// First, if the BackupEngineImpl shuts down with jobs outstanding, then
// it is possible that the Status in the future/promise is never read,
// resulting in an unchecked Status. Second, if there are items in the
// channel when the BackupEngineImpl is shutdown, these will also have
// Status that have not been checked. This
// TODO: Fix those issues so that the Status
io_status.PermitUncheckedError();
}
uint64_t size;
std::string checksum_hex;
std::string db_id;
std::string db_session_id;
IOStatus io_status;
};
// Exactly one of src_path and contents must be non-empty. If src_path is
// non-empty, the file is copied from this pathname. Otherwise, if contents is
// non-empty, the file will be created at dst_path with these contents.
struct CopyOrCreateWorkItem {
std::string src_path;
std::string dst_path;
std::string contents;
Env* src_env;
Env* dst_env;
EnvOptions src_env_options;
bool sync;
RateLimiter* rate_limiter;
uint64_t size_limit;
Statistics* stats;
std::promise<CopyOrCreateResult> result;
std::function<void()> progress_callback;
std::string src_checksum_func_name;
std::string src_checksum_hex;
std::string db_id;
std::string db_session_id;
CopyOrCreateWorkItem()
: src_path(""),
dst_path(""),
contents(""),
src_env(nullptr),
dst_env(nullptr),
src_env_options(),
sync(false),
rate_limiter(nullptr),
size_limit(0),
stats(nullptr),
src_checksum_func_name(kUnknownFileChecksumFuncName),
src_checksum_hex(""),
db_id(""),
db_session_id("") {}
CopyOrCreateWorkItem(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem& operator=(const CopyOrCreateWorkItem&) = delete;
CopyOrCreateWorkItem(CopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
CopyOrCreateWorkItem& operator=(CopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
src_path = std::move(o.src_path);
dst_path = std::move(o.dst_path);
contents = std::move(o.contents);
src_env = o.src_env;
dst_env = o.dst_env;
src_env_options = std::move(o.src_env_options);
sync = o.sync;
rate_limiter = o.rate_limiter;
size_limit = o.size_limit;
stats = o.stats;
result = std::move(o.result);
progress_callback = std::move(o.progress_callback);
src_checksum_func_name = std::move(o.src_checksum_func_name);
src_checksum_hex = std::move(o.src_checksum_hex);
db_id = std::move(o.db_id);
db_session_id = std::move(o.db_session_id);
return *this;
}
CopyOrCreateWorkItem(
std::string _src_path, std::string _dst_path, std::string _contents,
Env* _src_env, Env* _dst_env, EnvOptions _src_env_options, bool _sync,
RateLimiter* _rate_limiter, uint64_t _size_limit, Statistics* _stats,
std::function<void()> _progress_callback = []() {},
const std::string& _src_checksum_func_name =
kUnknownFileChecksumFuncName,
const std::string& _src_checksum_hex = "",
const std::string& _db_id = "", const std::string& _db_session_id = "")
: src_path(std::move(_src_path)),
dst_path(std::move(_dst_path)),
contents(std::move(_contents)),
src_env(_src_env),
dst_env(_dst_env),
src_env_options(std::move(_src_env_options)),
sync(_sync),
rate_limiter(_rate_limiter),
size_limit(_size_limit),
stats(_stats),
progress_callback(_progress_callback),
src_checksum_func_name(_src_checksum_func_name),
src_checksum_hex(_src_checksum_hex),
db_id(_db_id),
db_session_id(_db_session_id) {}
};
struct BackupAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
bool shared;
bool needed_to_copy;
Env* backup_env;
std::string dst_path_tmp;
std::string dst_path;
std::string dst_relative;
BackupAfterCopyOrCreateWorkItem()
: shared(false),
needed_to_copy(false),
backup_env(nullptr),
dst_path_tmp(""),
dst_path(""),
dst_relative("") {}
BackupAfterCopyOrCreateWorkItem(BackupAfterCopyOrCreateWorkItem&& o)
ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
BackupAfterCopyOrCreateWorkItem& operator=(
BackupAfterCopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
result = std::move(o.result);
shared = o.shared;
needed_to_copy = o.needed_to_copy;
backup_env = o.backup_env;
dst_path_tmp = std::move(o.dst_path_tmp);
dst_path = std::move(o.dst_path);
dst_relative = std::move(o.dst_relative);
return *this;
}
BackupAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
bool _shared, bool _needed_to_copy,
Env* _backup_env, std::string _dst_path_tmp,
std::string _dst_path,
std::string _dst_relative)
: result(std::move(_result)),
shared(_shared),
needed_to_copy(_needed_to_copy),
backup_env(_backup_env),
dst_path_tmp(std::move(_dst_path_tmp)),
dst_path(std::move(_dst_path)),
dst_relative(std::move(_dst_relative)) {}
};
struct RestoreAfterCopyOrCreateWorkItem {
std::future<CopyOrCreateResult> result;
std::string from_file;
std::string to_file;
std::string checksum_hex;
RestoreAfterCopyOrCreateWorkItem() : checksum_hex("") {}
RestoreAfterCopyOrCreateWorkItem(std::future<CopyOrCreateResult>&& _result,
const std::string& _from_file,
const std::string& _to_file,
const std::string& _checksum_hex)
: result(std::move(_result)),
from_file(_from_file),
to_file(_to_file),
checksum_hex(_checksum_hex) {}
RestoreAfterCopyOrCreateWorkItem(RestoreAfterCopyOrCreateWorkItem&& o)
ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
RestoreAfterCopyOrCreateWorkItem& operator=(
RestoreAfterCopyOrCreateWorkItem&& o) ROCKSDB_NOEXCEPT {
result = std::move(o.result);
checksum_hex = std::move(o.checksum_hex);
return *this;
}
};
bool initialized_;
std::mutex byte_report_mutex_;
mutable channel<CopyOrCreateWorkItem> files_to_copy_or_create_;
std::vector<port::Thread> threads_;
std::atomic<CpuPriority> threads_cpu_priority_;
// Certain operations like PurgeOldBackups and DeleteBackup will trigger
// automatic GarbageCollect (true) unless we've already done one in this
// session and have not failed to delete backup files since then (false).
bool might_need_garbage_collect_ = true;
// Adds a file to the backup work queue to be copied or created if it doesn't
// already exist.
//
// Exactly one of src_dir and contents must be non-empty.
//
// @param src_dir If non-empty, the file in this directory named fname will be
// copied.
// @param fname Name of destination file and, in case of copy, source file.
// @param contents If non-empty, the file will be created with these contents.
IOStatus AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::vector<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
BackupID backup_id, bool shared, const std::string& src_dir,
const std::string& fname, // starts with "/"
const EnvOptions& src_env_options, RateLimiter* rate_limiter,
FileType file_type, uint64_t size_bytes, Statistics* stats,
uint64_t size_limit = 0, bool shared_checksum = false,
std::function<void()> progress_callback = []() {},
const std::string& contents = std::string(),
const std::string& src_checksum_func_name = kUnknownFileChecksumFuncName,
const std::string& src_checksum_str = kUnknownFileChecksum);
// backup state data
BackupID latest_backup_id_;
BackupID latest_valid_backup_id_;
std::map<BackupID, std::unique_ptr<BackupMeta>> backups_;
std::map<BackupID, std::pair<IOStatus, std::unique_ptr<BackupMeta>>>
corrupt_backups_;
std::unordered_map<std::string,
std::shared_ptr<FileInfo>> backuped_file_infos_;
std::atomic<bool> stop_backup_;
// options data
BackupEngineOptions options_;
Env* db_env_;
Env* backup_env_;
// directories
std::unique_ptr<FSDirectory> backup_directory_;
std::unique_ptr<FSDirectory> shared_directory_;
std::unique_ptr<FSDirectory> meta_directory_;
std::unique_ptr<FSDirectory> private_directory_;
static const size_t kDefaultCopyFileBufferSize = 5 * 1024 * 1024LL; // 5MB
bool read_only_;
BackupStatistics backup_statistics_;
std::unordered_set<std::string> reported_ignored_fields_;
static const size_t kMaxAppMetaSize = 1024 * 1024; // 1MB
std::shared_ptr<FileSystem> db_fs_;
std::shared_ptr<FileSystem> backup_fs_;
IOOptions io_options_ = IOOptions();
public:
std::unique_ptr<TEST_FutureSchemaVersion2Options> test_future_options_;
};
// -------- BackupEngineImplThreadSafe class ---------
// This locking layer for thread safety in the public API is layered on
// top to prevent accidental recursive locking with RWMutex, which is UB.
// Note: BackupEngineReadOnlyBase inherited twice, but has no fields
class BackupEngineImplThreadSafe : public BackupEngine,
public BackupEngineReadOnly {
public:
BackupEngineImplThreadSafe(const BackupEngineOptions& options, Env* db_env,
bool read_only = false)
: impl_(options, db_env, read_only) {}
~BackupEngineImplThreadSafe() override {}
using BackupEngine::CreateNewBackupWithMetadata;
IOStatus CreateNewBackupWithMetadata(const CreateBackupOptions& options,
DB* db, const std::string& app_metadata,
BackupID* new_backup_id) override {
WriteLock lock(&mutex_);
return impl_.CreateNewBackupWithMetadata(options, db, app_metadata,
new_backup_id);
}
IOStatus PurgeOldBackups(uint32_t num_backups_to_keep) override {
WriteLock lock(&mutex_);
return impl_.PurgeOldBackups(num_backups_to_keep);
}
IOStatus DeleteBackup(BackupID backup_id) override {
WriteLock lock(&mutex_);
return impl_.DeleteBackup(backup_id);
}
void StopBackup() override {
// No locking needed
impl_.StopBackup();
}
IOStatus GarbageCollect() override {
WriteLock lock(&mutex_);
return impl_.GarbageCollect();
}
Status GetLatestBackupInfo(BackupInfo* backup_info,
bool include_file_details = false) const override {
ReadLock lock(&mutex_);
return impl_.GetBackupInfo(kLatestBackupIDMarker, backup_info,
include_file_details);
}
Status GetBackupInfo(BackupID backup_id, BackupInfo* backup_info,
bool include_file_details = false) const override {
ReadLock lock(&mutex_);
return impl_.GetBackupInfo(backup_id, backup_info, include_file_details);
}
void GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const override {
ReadLock lock(&mutex_);
impl_.GetBackupInfo(backup_info, include_file_details);
}
void GetCorruptedBackups(
std::vector<BackupID>* corrupt_backup_ids) const override {
ReadLock lock(&mutex_);
impl_.GetCorruptedBackups(corrupt_backup_ids);
}
using BackupEngine::RestoreDBFromBackup;
IOStatus RestoreDBFromBackup(const RestoreOptions& options,
BackupID backup_id, const std::string& db_dir,
const std::string& wal_dir) const override {
ReadLock lock(&mutex_);
return impl_.RestoreDBFromBackup(options, backup_id, db_dir, wal_dir);
}
using BackupEngine::RestoreDBFromLatestBackup;
IOStatus RestoreDBFromLatestBackup(
const RestoreOptions& options, const std::string& db_dir,
const std::string& wal_dir) const override {
// Defer to above function, which locks
return RestoreDBFromBackup(options, kLatestBackupIDMarker, db_dir, wal_dir);
}
IOStatus VerifyBackup(BackupID backup_id,
bool verify_with_checksum = false) const override {
ReadLock lock(&mutex_);
return impl_.VerifyBackup(backup_id, verify_with_checksum);
}
// Not public API but needed
IOStatus Initialize() {
// No locking needed
return impl_.Initialize();
}
// Not public API but used in testing
void TEST_EnableWriteFutureSchemaVersion2(
const TEST_FutureSchemaVersion2Options& options) {
impl_.test_future_options_.reset(
new TEST_FutureSchemaVersion2Options(options));
}
private:
mutable port::RWMutex mutex_;
BackupEngineImpl impl_;
};
IOStatus BackupEngine::Open(const BackupEngineOptions& options, Env* env,
BackupEngine** backup_engine_ptr) {
std::unique_ptr<BackupEngineImplThreadSafe> backup_engine(
new BackupEngineImplThreadSafe(options, env));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return IOStatus::OK();
}
BackupEngineImpl::BackupEngineImpl(const BackupEngineOptions& options,
Env* db_env, bool read_only)
: initialized_(false),
threads_cpu_priority_(),
latest_backup_id_(0),
latest_valid_backup_id_(0),
stop_backup_(false),
options_(options),
db_env_(db_env),
backup_env_(options.backup_env != nullptr ? options.backup_env : db_env_),
read_only_(read_only) {
if (options_.backup_rate_limiter == nullptr &&
options_.backup_rate_limit > 0) {
options_.backup_rate_limiter.reset(
NewGenericRateLimiter(options_.backup_rate_limit));
}
if (options_.restore_rate_limiter == nullptr &&
options_.restore_rate_limit > 0) {
options_.restore_rate_limiter.reset(
NewGenericRateLimiter(options_.restore_rate_limit));
}
db_fs_ = db_env_->GetFileSystem();
backup_fs_ = backup_env_->GetFileSystem();
}
BackupEngineImpl::~BackupEngineImpl() {
files_to_copy_or_create_.sendEof();
for (auto& t : threads_) {
t.join();
}
LogFlush(options_.info_log);
for (const auto& it : corrupt_backups_) {
it.second.first.PermitUncheckedError();
}
}
IOStatus BackupEngineImpl::Initialize() {
assert(!initialized_);
initialized_ = true;
if (read_only_) {
ROCKS_LOG_INFO(options_.info_log, "Starting read_only backup engine");
}
options_.Dump(options_.info_log);
auto meta_path = GetAbsolutePath(kMetaDirName);
if (!read_only_) {
// we might need to clean up from previous crash or I/O errors
might_need_garbage_collect_ = true;
if (options_.max_valid_backups_to_open != port::kMaxInt32) {
options_.max_valid_backups_to_open = port::kMaxInt32;
ROCKS_LOG_WARN(
options_.info_log,
"`max_valid_backups_to_open` is not set to the default value. Ignoring "
"its value since BackupEngine is not read-only.");
}
// gather the list of directories that we need to create
std::vector<std::pair<std::string, std::unique_ptr<FSDirectory>*>>
directories;
directories.emplace_back(GetAbsolutePath(), &backup_directory_);
if (options_.share_table_files) {
if (options_.share_files_with_checksum) {
directories.emplace_back(
GetAbsolutePath(GetSharedFileWithChecksumRel()),
&shared_directory_);
} else {
directories.emplace_back(GetAbsolutePath(GetSharedFileRel()),
&shared_directory_);
}
}
directories.emplace_back(GetAbsolutePath(kPrivateDirName),
&private_directory_);
directories.emplace_back(meta_path, &meta_directory_);
// create all the dirs we need
for (const auto& d : directories) {
IOStatus io_s =
backup_fs_->CreateDirIfMissing(d.first, io_options_, nullptr);
if (io_s.ok()) {
io_s =
backup_fs_->NewDirectory(d.first, io_options_, d.second, nullptr);
}
if (!io_s.ok()) {
return io_s;
}
}
}
std::vector<std::string> backup_meta_files;
{
IOStatus io_s = backup_fs_->GetChildren(meta_path, io_options_,
&backup_meta_files, nullptr);
if (io_s.IsNotFound()) {
return IOStatus::NotFound(meta_path + " is missing");
} else if (!io_s.ok()) {
return io_s;
}
}
// create backups_ structure
for (auto& file : backup_meta_files) {
ROCKS_LOG_INFO(options_.info_log, "Detected backup %s", file.c_str());
BackupID backup_id = 0;
sscanf(file.c_str(), "%u", &backup_id);
if (backup_id == 0 || file != ROCKSDB_NAMESPACE::ToString(backup_id)) {
// Invalid file name, will be deleted with auto-GC when user
// initiates an append or write operation. (Behave as read-only until
// then.)
ROCKS_LOG_INFO(options_.info_log, "Skipping unrecognized meta file %s",
file.c_str());
continue;
}
assert(backups_.find(backup_id) == backups_.end());
// Insert all the (backup_id, BackupMeta) that will be loaded later
// The loading performed later will check whether there are corrupt backups
// and move the corrupt backups to corrupt_backups_
backups_.insert(std::make_pair(
backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(backup_id, false /* tmp */),
GetBackupMetaFile(backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_, backup_fs_))));
}
latest_backup_id_ = 0;
latest_valid_backup_id_ = 0;
if (options_.destroy_old_data) { // Destroy old data
assert(!read_only_);
ROCKS_LOG_INFO(
options_.info_log,
"Backup Engine started with destroy_old_data == true, deleting all "
"backups");
IOStatus io_s = PurgeOldBackups(0);
if (io_s.ok()) {
io_s = GarbageCollect();
}
if (!io_s.ok()) {
return io_s;
}
} else { // Load data from storage
// abs_path_to_size: maps absolute paths of files in backup directory to
// their corresponding sizes
std::unordered_map<std::string, uint64_t> abs_path_to_size;
// Insert files and their sizes in backup sub-directories (shared and
// shared_checksum) to abs_path_to_size
for (const auto& rel_dir :
{GetSharedFileRel(), GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
IOStatus io_s =
ReadChildFileCurrentSizes(abs_dir, backup_fs_, &abs_path_to_size);
if (!io_s.ok()) {
// I/O error likely impacting all backups
return io_s;
}
}
// load the backups if any, until valid_backups_to_open of the latest
// non-corrupted backups have been successfully opened.
int valid_backups_to_open = options_.max_valid_backups_to_open;
for (auto backup_iter = backups_.rbegin();
backup_iter != backups_.rend();
++backup_iter) {
assert(latest_backup_id_ == 0 || latest_backup_id_ > backup_iter->first);
if (latest_backup_id_ == 0) {
latest_backup_id_ = backup_iter->first;
}
if (valid_backups_to_open == 0) {
break;
}
// Insert files and their sizes in backup sub-directories
// (private/backup_id) to abs_path_to_size
IOStatus io_s = ReadChildFileCurrentSizes(
GetAbsolutePath(GetPrivateFileRel(backup_iter->first)), backup_fs_,
&abs_path_to_size);
if (io_s.ok()) {
io_s = backup_iter->second->LoadFromFile(
options_.backup_dir, abs_path_to_size,
options_.backup_rate_limiter.get(), options_.info_log,
&reported_ignored_fields_);
}
if (io_s.IsCorruption() || io_s.IsNotSupported()) {
ROCKS_LOG_INFO(options_.info_log, "Backup %u corrupted -- %s",
backup_iter->first, io_s.ToString().c_str());
corrupt_backups_.insert(std::make_pair(
backup_iter->first,
std::make_pair(io_s, std::move(backup_iter->second))));
} else if (!io_s.ok()) {
// Distinguish corruption errors from errors in the backup Env.
// Errors in the backup Env (i.e., this code path) will cause Open() to
// fail, whereas corruption errors would not cause Open() failures.
return io_s;
} else {
ROCKS_LOG_INFO(options_.info_log, "Loading backup %" PRIu32 " OK:\n%s",
backup_iter->first,
backup_iter->second->GetInfoString().c_str());
assert(latest_valid_backup_id_ == 0 ||
latest_valid_backup_id_ > backup_iter->first);
if (latest_valid_backup_id_ == 0) {
latest_valid_backup_id_ = backup_iter->first;
}
--valid_backups_to_open;
}
}
for (const auto& corrupt : corrupt_backups_) {
backups_.erase(backups_.find(corrupt.first));
}
// erase the backups before max_valid_backups_to_open
int num_unopened_backups;
if (options_.max_valid_backups_to_open == 0) {
num_unopened_backups = 0;
} else {
num_unopened_backups =
std::max(0, static_cast<int>(backups_.size()) -
options_.max_valid_backups_to_open);
}
for (int i = 0; i < num_unopened_backups; ++i) {
assert(backups_.begin()->second->Empty());
backups_.erase(backups_.begin());
}
}
ROCKS_LOG_INFO(options_.info_log, "Latest backup is %u", latest_backup_id_);
ROCKS_LOG_INFO(options_.info_log, "Latest valid backup is %u",
latest_valid_backup_id_);
// set up threads perform copies from files_to_copy_or_create_ in the
// background
threads_cpu_priority_ = CpuPriority::kNormal;
threads_.reserve(options_.max_background_operations);
for (int t = 0; t < options_.max_background_operations; t++) {
threads_.emplace_back([this]() {
#if defined(_GNU_SOURCE) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ(2, 12)
pthread_setname_np(pthread_self(), "backup_engine");
#endif
#endif
CpuPriority current_priority = CpuPriority::kNormal;
CopyOrCreateWorkItem work_item;
uint64_t bytes_toward_next_callback = 0;
while (files_to_copy_or_create_.read(work_item)) {
CpuPriority priority = threads_cpu_priority_;
if (current_priority != priority) {
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::Initialize:SetCpuPriority", &priority);
port::SetCpuPriority(0, priority);
current_priority = priority;
}
// `bytes_read` and `bytes_written` stats are enabled based on
// compile-time support and cannot be dynamically toggled. So we do not
// need to worry about `PerfLevel` here, unlike many other
// `IOStatsContext` / `PerfContext` stats.
uint64_t prev_bytes_read = IOSTATS(bytes_read);
uint64_t prev_bytes_written = IOSTATS(bytes_written);
CopyOrCreateResult result;
result.io_status = CopyOrCreateFile(
work_item.src_path, work_item.dst_path, work_item.contents,
work_item.size_limit, work_item.src_env, work_item.dst_env,
work_item.src_env_options, work_item.sync, work_item.rate_limiter,
work_item.progress_callback, &bytes_toward_next_callback,
&result.size, &result.checksum_hex);
RecordTick(work_item.stats, BACKUP_READ_BYTES,
IOSTATS(bytes_read) - prev_bytes_read);
RecordTick(work_item.stats, BACKUP_WRITE_BYTES,
IOSTATS(bytes_written) - prev_bytes_written);
result.db_id = work_item.db_id;
result.db_session_id = work_item.db_session_id;
if (result.io_status.ok() && !work_item.src_checksum_hex.empty()) {
// unknown checksum function name implies no db table file checksum in
// db manifest; work_item.src_checksum_hex not empty means
// backup engine has calculated its crc32c checksum for the table
// file; therefore, we are able to compare the checksums.
if (work_item.src_checksum_func_name ==
kUnknownFileChecksumFuncName ||
work_item.src_checksum_func_name == kDbFileChecksumFuncName) {
if (work_item.src_checksum_hex != result.checksum_hex) {
std::string checksum_info(
"Expected checksum is " + work_item.src_checksum_hex +
" while computed checksum is " + result.checksum_hex);
result.io_status = IOStatus::Corruption(
"Checksum mismatch after copying to " + work_item.dst_path +
": " + checksum_info);
}
} else {
// FIXME(peterd): dead code?
std::string checksum_function_info(
"Existing checksum function is " +
work_item.src_checksum_func_name +
" while provided checksum function is " +
kBackupFileChecksumFuncName);
ROCKS_LOG_INFO(
options_.info_log,
"Unable to verify checksum after copying to %s: %s\n",
work_item.dst_path.c_str(), checksum_function_info.c_str());
}
}
work_item.result.set_value(std::move(result));
}
});
}
ROCKS_LOG_INFO(options_.info_log, "Initialized BackupEngine");
return IOStatus::OK();
}
IOStatus BackupEngineImpl::CreateNewBackupWithMetadata(
const CreateBackupOptions& options, DB* db, const std::string& app_metadata,
BackupID* new_backup_id_ptr) {
assert(initialized_);
assert(!read_only_);
if (app_metadata.size() > kMaxAppMetaSize) {
return IOStatus::InvalidArgument("App metadata too large");
}
if (options.decrease_background_thread_cpu_priority) {
if (options.background_thread_cpu_priority < threads_cpu_priority_) {
threads_cpu_priority_.store(options.background_thread_cpu_priority);
}
}
BackupID new_backup_id = latest_backup_id_ + 1;
// `bytes_read` and `bytes_written` stats are enabled based on compile-time
// support and cannot be dynamically toggled. So we do not need to worry about
// `PerfLevel` here, unlike many other `IOStatsContext` / `PerfContext` stats.
uint64_t prev_bytes_read = IOSTATS(bytes_read);
uint64_t prev_bytes_written = IOSTATS(bytes_written);
assert(backups_.find(new_backup_id) == backups_.end());
auto private_dir = GetAbsolutePath(GetPrivateFileRel(new_backup_id));
IOStatus io_s = backup_fs_->FileExists(private_dir, io_options_, nullptr);
if (io_s.ok()) {
// maybe last backup failed and left partial state behind, clean it up.
// need to do this before updating backups_ such that a private dir
// named after new_backup_id will be cleaned up.
// (If an incomplete new backup is followed by an incomplete delete
// of the latest full backup, then there could be more than one next
// id with a private dir, the last thing to be deleted in delete
// backup, but all will be cleaned up with a GarbageCollect.)
io_s = GarbageCollect();
} else if (io_s.IsNotFound()) {
// normal case, the new backup's private dir doesn't exist yet
io_s = IOStatus::OK();
}
auto ret = backups_.insert(std::make_pair(
new_backup_id, std::unique_ptr<BackupMeta>(new BackupMeta(
GetBackupMetaFile(new_backup_id, false /* tmp */),
GetBackupMetaFile(new_backup_id, true /* tmp */),
&backuped_file_infos_, backup_env_, backup_fs_))));
assert(ret.second == true);
auto& new_backup = ret.first->second;
new_backup->RecordTimestamp();
new_backup->SetAppMetadata(app_metadata);
auto start_backup = backup_env_->NowMicros();
ROCKS_LOG_INFO(options_.info_log,
"Started the backup process -- creating backup %u",
new_backup_id);
if (options_.share_table_files && !options_.share_files_with_checksum) {
ROCKS_LOG_WARN(options_.info_log,
"BackupEngineOptions::share_files_with_checksum=false is "
"DEPRECATED and could lead to data loss.");
}
if (io_s.ok()) {
io_s = backup_fs_->CreateDir(private_dir, io_options_, nullptr);
}
// A set into which we will insert the dst_paths that are calculated for live
// files and live WAL files.
// This is used to check whether a live files shares a dst_path with another
// live file.
std::unordered_set<std::string> live_dst_paths;
std::vector<BackupAfterCopyOrCreateWorkItem> backup_items_to_finish;
// Add a CopyOrCreateWorkItem to the channel for each live file
Status disabled = db->DisableFileDeletions();
DBOptions db_options = db->GetDBOptions();
Statistics* stats = db_options.statistics.get();
if (io_s.ok()) {
CheckpointImpl checkpoint(db);
uint64_t sequence_number = 0;
FileChecksumGenFactory* db_checksum_factory =
db_options.file_checksum_gen_factory.get();
const std::string kFileChecksumGenFactoryName =
"FileChecksumGenCrc32cFactory";
bool compare_checksum =
db_checksum_factory != nullptr &&
db_checksum_factory->Name() == kFileChecksumGenFactoryName
? true
: false;
EnvOptions src_raw_env_options(db_options);
RateLimiter* rate_limiter = options_.backup_rate_limiter.get();
io_s = status_to_io_status(checkpoint.CreateCustomCheckpoint(
[&](const std::string& /*src_dirname*/, const std::string& /*fname*/,
FileType) {
// custom checkpoint will switch to calling copy_file_cb after it sees
// NotSupported returned from link_file_cb.
return IOStatus::NotSupported();
} /* link_file_cb */,
[&](const std::string& src_dirname, const std::string& fname,
uint64_t size_limit_bytes, FileType type,
const std::string& checksum_func_name,
const std::string& checksum_val) {
if (type == kWalFile && !options_.backup_log_files) {
return IOStatus::OK();
}
Log(options_.info_log, "add file for backup %s", fname.c_str());
uint64_t size_bytes = 0;
IOStatus io_st;
if (type == kTableFile || type == kBlobFile) {
io_st = db_fs_->GetFileSize(src_dirname + "/" + fname, io_options_,
&size_bytes, nullptr);
}
EnvOptions src_env_options;
switch (type) {
case kWalFile:
src_env_options =
db_env_->OptimizeForLogRead(src_raw_env_options);
break;
case kTableFile:
src_env_options = db_env_->OptimizeForCompactionTableRead(
src_raw_env_options, ImmutableDBOptions(db_options));
break;
case kDescriptorFile:
src_env_options =
db_env_->OptimizeForManifestRead(src_raw_env_options);
break;
case kBlobFile:
src_env_options = db_env_->OptimizeForBlobFileRead(
src_raw_env_options, ImmutableDBOptions(db_options));
break;
default:
// Other backed up files (like options file) are not read by live
// DB, so don't need to worry about avoiding mixing buffered and
// direct I/O. Just use plain defaults.
src_env_options = src_raw_env_options;
break;
}
if (io_st.ok()) {
io_st = AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish, new_backup_id,
options_.share_table_files &&
(type == kTableFile || type == kBlobFile),
src_dirname, fname, src_env_options, rate_limiter, type,
size_bytes, db_options.statistics.get(), size_limit_bytes,
options_.share_files_with_checksum &&
(type == kTableFile || type == kBlobFile),
options.progress_callback, "" /* contents */,
checksum_func_name, checksum_val);
}
return io_st;
} /* copy_file_cb */,
[&](const std::string& fname, const std::string& contents,
FileType type) {
Log(options_.info_log, "add file for backup %s", fname.c_str());
return AddBackupFileWorkItem(
live_dst_paths, backup_items_to_finish, new_backup_id,
false /* shared */, "" /* src_dir */, fname,
EnvOptions() /* src_env_options */, rate_limiter, type,
contents.size(), db_options.statistics.get(), 0 /* size_limit */,
false /* shared_checksum */, options.progress_callback, contents);
} /* create_file_cb */,
&sequence_number, options.flush_before_backup ? 0 : port::kMaxUint64,
compare_checksum));
if (io_s.ok()) {
new_backup->SetSequenceNumber(sequence_number);
}
}
ROCKS_LOG_INFO(options_.info_log, "add files for backup done, wait finish.");
IOStatus item_io_status;
for (auto& item : backup_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_io_status = result.io_status;
if (item_io_status.ok() && item.shared && item.needed_to_copy) {
item_io_status = item.backup_env->GetFileSystem()->RenameFile(
item.dst_path_tmp, item.dst_path, io_options_, nullptr);
}
if (item_io_status.ok()) {
item_io_status = new_backup.get()->AddFile(std::make_shared<FileInfo>(
item.dst_relative, result.size, result.checksum_hex, result.db_id,
result.db_session_id));
}
if (!item_io_status.ok()) {
io_s = item_io_status;
}
}
// we copied all the files, enable file deletions
if (disabled.ok()) { // If we successfully disabled file deletions
db->EnableFileDeletions(false).PermitUncheckedError();
}
auto backup_time = backup_env_->NowMicros() - start_backup;
if (io_s.ok()) {
// persist the backup metadata on the disk
io_s = new_backup->StoreToFile(options_.sync, test_future_options_.get());
}
if (io_s.ok() && options_.sync) {
std::unique_ptr<FSDirectory> backup_private_directory;
backup_fs_
->NewDirectory(GetAbsolutePath(GetPrivateFileRel(new_backup_id, false)),
io_options_, &backup_private_directory, nullptr)
.PermitUncheckedError();
if (backup_private_directory != nullptr) {
io_s = backup_private_directory->Fsync(io_options_, nullptr);
}
if (io_s.ok() && private_directory_ != nullptr) {
io_s = private_directory_->Fsync(io_options_, nullptr);
}
if (io_s.ok() && meta_directory_ != nullptr) {
io_s = meta_directory_->Fsync(io_options_, nullptr);
}
if (io_s.ok() && shared_directory_ != nullptr) {
io_s = shared_directory_->Fsync(io_options_, nullptr);
}
if (io_s.ok() && backup_directory_ != nullptr) {
io_s = backup_directory_->Fsync(io_options_, nullptr);
}
}
if (io_s.ok()) {
backup_statistics_.IncrementNumberSuccessBackup();
// here we know that we succeeded and installed the new backup
latest_backup_id_ = new_backup_id;
latest_valid_backup_id_ = new_backup_id;
if (new_backup_id_ptr) {
*new_backup_id_ptr = new_backup_id;
}
ROCKS_LOG_INFO(options_.info_log, "Backup DONE. All is good");
// backup_speed is in byte/second
double backup_speed = new_backup->GetSize() / (1.048576 * backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup number of files: %u",
new_backup->GetNumberFiles());
char human_size[16];
AppendHumanBytes(new_backup->GetSize(), human_size, sizeof(human_size));
ROCKS_LOG_INFO(options_.info_log, "Backup size: %s", human_size);
ROCKS_LOG_INFO(options_.info_log, "Backup time: %" PRIu64 " microseconds",
backup_time);
ROCKS_LOG_INFO(options_.info_log, "Backup speed: %.3f MB/s", backup_speed);
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s",
backup_statistics_.ToString().c_str());
} else {
backup_statistics_.IncrementNumberFailBackup();
// clean all the files we might have created
ROCKS_LOG_INFO(options_.info_log, "Backup failed -- %s",
io_s.ToString().c_str());
ROCKS_LOG_INFO(options_.info_log, "Backup Statistics %s\n",
backup_statistics_.ToString().c_str());
// delete files that we might have already written
might_need_garbage_collect_ = true;
DeleteBackup(new_backup_id).PermitUncheckedError();
}
RecordTick(stats, BACKUP_READ_BYTES, IOSTATS(bytes_read) - prev_bytes_read);
RecordTick(stats, BACKUP_WRITE_BYTES,
IOSTATS(bytes_written) - prev_bytes_written);
return io_s;
}
IOStatus BackupEngineImpl::PurgeOldBackups(uint32_t num_backups_to_keep) {
assert(initialized_);
assert(!read_only_);
// Best effort deletion even with errors
IOStatus overall_status = IOStatus::OK();
ROCKS_LOG_INFO(options_.info_log, "Purging old backups, keeping %u",
num_backups_to_keep);
std::vector<BackupID> to_delete;
auto itr = backups_.begin();
while ((backups_.size() - to_delete.size()) > num_backups_to_keep) {
to_delete.push_back(itr->first);
itr++;
}
for (auto backup_id : to_delete) {
// Do not GC until end
IOStatus io_s = DeleteBackupNoGC(backup_id);
if (!io_s.ok()) {
overall_status = io_s;
}
}
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
IOStatus io_s = GarbageCollect();
if (!io_s.ok() && overall_status.ok()) {
overall_status = io_s;
}
}
return overall_status;
}
IOStatus BackupEngineImpl::DeleteBackup(BackupID backup_id) {
IOStatus s1 = DeleteBackupNoGC(backup_id);
IOStatus s2 = IOStatus::OK();
// Clean up after any incomplete backup deletion, potentially from
// earlier session.
if (might_need_garbage_collect_) {
s2 = GarbageCollect();
}
if (!s1.ok()) {
// Any failure in the primary objective trumps any failure in the
// secondary objective.
s2.PermitUncheckedError();
return s1;
} else {
return s2;
}
}
// Does not auto-GarbageCollect nor lock
IOStatus BackupEngineImpl::DeleteBackupNoGC(BackupID backup_id) {
assert(initialized_);
assert(!read_only_);
ROCKS_LOG_INFO(options_.info_log, "Deleting backup %u", backup_id);
auto backup = backups_.find(backup_id);
if (backup != backups_.end()) {
IOStatus io_s = backup->second->Delete();
if (!io_s.ok()) {
return io_s;
}
backups_.erase(backup);
} else {
auto corrupt = corrupt_backups_.find(backup_id);
if (corrupt == corrupt_backups_.end()) {
return IOStatus::NotFound("Backup not found");
}
IOStatus io_s = corrupt->second.second->Delete();
if (!io_s.ok()) {
return io_s;
}
corrupt->second.first.PermitUncheckedError();
corrupt_backups_.erase(corrupt);
}
// After removing meta file, best effort deletion even with errors.
// (Don't delete other files if we can't delete the meta file right
// now.)
std::vector<std::string> to_delete;
for (auto& itr : backuped_file_infos_) {
if (itr.second->refs == 0) {
IOStatus io_s = backup_fs_->DeleteFile(GetAbsolutePath(itr.first),
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s", itr.first.c_str(),
io_s.ToString().c_str());
to_delete.push_back(itr.first);
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
for (auto& td : to_delete) {
backuped_file_infos_.erase(td);
}
// take care of private dirs -- GarbageCollect() will take care of them
// if they are not empty
std::string private_dir = GetPrivateFileRel(backup_id);
IOStatus io_s =
backup_fs_->DeleteDir(GetAbsolutePath(private_dir), io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting private dir %s -- %s",
private_dir.c_str(), io_s.ToString().c_str());
if (!io_s.ok()) {
// Full gc or trying again later might work
might_need_garbage_collect_ = true;
}
return IOStatus::OK();
}
void BackupEngineImpl::SetBackupInfoFromBackupMeta(
BackupID id, const BackupMeta& meta, BackupInfo* backup_info,
bool include_file_details) const {
*backup_info = BackupInfo(id, meta.GetTimestamp(), meta.GetSize(),
meta.GetNumberFiles(), meta.GetAppMetadata());
std::string dir = options_.backup_dir + "/" + kPrivateDirSlash +
ROCKSDB_NAMESPACE::ToString(id);
if (include_file_details) {
auto& file_details = backup_info->file_details;
file_details.reserve(meta.GetFiles().size());
for (auto& file_ptr : meta.GetFiles()) {
BackupFileInfo& finfo = *file_details.emplace(file_details.end());
finfo.relative_filename = file_ptr->filename;
finfo.size = file_ptr->size;
finfo.directory = dir;
uint64_t number;
FileType type;
bool ok = ParseFileName(file_ptr->filename, &number, &type);
if (ok) {
finfo.file_number = number;
finfo.file_type = type;
}
// TODO: temperature, file_checksum, file_checksum_func_name
}
backup_info->name_for_open = GetAbsolutePath(GetPrivateFileRel(id));
backup_info->name_for_open.pop_back(); // remove trailing '/'
backup_info->env_for_open = meta.GetEnvForOpen();
}
}
Status BackupEngineImpl::GetBackupInfo(BackupID backup_id,
BackupInfo* backup_info,
bool include_file_details) const {
assert(initialized_);
if (backup_id == kLatestBackupIDMarker) {
// Note: Read latest_valid_backup_id_ inside of lock
backup_id = latest_valid_backup_id_;
}
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return Status::Corruption(corrupt_itr->second.first.ToString());
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return Status::NotFound("Backup not found");
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return Status::NotFound("Backup not found");
}
SetBackupInfoFromBackupMeta(backup_id, *backup, backup_info,
include_file_details);
return Status::OK();
}
void BackupEngineImpl::GetBackupInfo(std::vector<BackupInfo>* backup_info,
bool include_file_details) const {
assert(initialized_);
backup_info->resize(backups_.size());
size_t i = 0;
for (auto& backup : backups_) {
const BackupMeta& meta = *backup.second;
if (!meta.Empty()) {
SetBackupInfoFromBackupMeta(backup.first, meta, &backup_info->at(i++),
include_file_details);
}
}
}
void BackupEngineImpl::GetCorruptedBackups(
std::vector<BackupID>* corrupt_backup_ids) const {
assert(initialized_);
corrupt_backup_ids->reserve(corrupt_backups_.size());
for (auto& backup : corrupt_backups_) {
corrupt_backup_ids->push_back(backup.first);
}
}
IOStatus BackupEngineImpl::RestoreDBFromBackup(
const RestoreOptions& options, BackupID backup_id,
const std::string& db_dir, const std::string& wal_dir) const {
assert(initialized_);
if (backup_id == kLatestBackupIDMarker) {
// Note: Read latest_valid_backup_id_ inside of lock
backup_id = latest_valid_backup_id_;
}
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return IOStatus::NotFound("Backup not found");
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return IOStatus::NotFound("Backup not found");
}
ROCKS_LOG_INFO(options_.info_log, "Restoring backup id %u\n", backup_id);
ROCKS_LOG_INFO(options_.info_log, "keep_log_files: %d\n",
static_cast<int>(options.keep_log_files));
// just in case. Ignore errors
db_fs_->CreateDirIfMissing(db_dir, io_options_, nullptr)
.PermitUncheckedError();
db_fs_->CreateDirIfMissing(wal_dir, io_options_, nullptr)
.PermitUncheckedError();
if (options.keep_log_files) {
// delete files in db_dir, but keep all the log files
DeleteChildren(db_dir, 1 << kWalFile);
// move all the files from archive dir to wal_dir
std::string archive_dir = ArchivalDirectory(wal_dir);
std::vector<std::string> archive_files;
db_fs_->GetChildren(archive_dir, io_options_, &archive_files, nullptr)
.PermitUncheckedError(); // ignore errors
for (const auto& f : archive_files) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && type == kWalFile) {
ROCKS_LOG_INFO(options_.info_log,
"Moving log file from archive/ to wal_dir: %s",
f.c_str());
IOStatus io_s = db_fs_->RenameFile(
archive_dir + "/" + f, wal_dir + "/" + f, io_options_, nullptr);
if (!io_s.ok()) {
// if we can't move log file from archive_dir to wal_dir,
// we should fail, since it might mean data loss
return io_s;
}
}
}
} else {
DeleteChildren(wal_dir);
DeleteChildren(ArchivalDirectory(wal_dir));
DeleteChildren(db_dir);
}
IOStatus io_s;
std::vector<RestoreAfterCopyOrCreateWorkItem> restore_items_to_finish;
std::string temporary_current_file;
std::string final_current_file;
std::unique_ptr<FSDirectory> db_dir_for_fsync;
std::unique_ptr<FSDirectory> wal_dir_for_fsync;
for (const auto& file_info : backup->GetFiles()) {
const std::string& file = file_info->filename;
// 1. get DB filename
std::string dst = file_info->GetDbFileName();
// 2. find the filetype
uint64_t number;
FileType type;
bool ok = ParseFileName(dst, &number, &type);
if (!ok) {
return IOStatus::Corruption("Backup corrupted: Fail to parse filename " +
dst);
}
// 3. Construct the final path
// kWalFile lives in wal_dir and all the rest live in db_dir
if (type == kWalFile) {
dst = wal_dir + "/" + dst;
if (options_.sync && !wal_dir_for_fsync) {
io_s = db_fs_->NewDirectory(wal_dir, io_options_, &wal_dir_for_fsync,
nullptr);
if (!io_s.ok()) {
return io_s;
}
}
} else {
dst = db_dir + "/" + dst;
if (options_.sync && !db_dir_for_fsync) {
io_s = db_fs_->NewDirectory(db_dir, io_options_, &db_dir_for_fsync,
nullptr);
if (!io_s.ok()) {
return io_s;
}
}
}
// For atomicity, initially restore CURRENT file to a temporary name.
// This is useful even without options_.sync e.g. in case the restore
// process is interrupted.
if (type == kCurrentFile) {
final_current_file = dst;
dst = temporary_current_file = dst + ".tmp";
}
ROCKS_LOG_INFO(options_.info_log, "Restoring %s to %s\n", file.c_str(),
dst.c_str());
CopyOrCreateWorkItem copy_or_create_work_item(
GetAbsolutePath(file), dst, "" /* contents */, backup_env_, db_env_,
EnvOptions() /* src_env_options */, options_.sync,
options_.restore_rate_limiter.get(), 0 /* size_limit */,
nullptr /* stats */);
RestoreAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), file, dst,
file_info->checksum_hex);
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
restore_items_to_finish.push_back(
std::move(after_copy_or_create_work_item));
}
IOStatus item_io_status;
for (auto& item : restore_items_to_finish) {
item.result.wait();
auto result = item.result.get();
item_io_status = result.io_status;
// Note: It is possible that both of the following bad-status cases occur
// during copying. But, we only return one status.
if (!item_io_status.ok()) {
io_s = item_io_status;
break;
} else if (!item.checksum_hex.empty() &&
item.checksum_hex != result.checksum_hex) {
io_s = IOStatus::Corruption(
"While restoring " + item.from_file + " -> " + item.to_file +
": expected checksum is " + item.checksum_hex +
" while computed checksum is " + result.checksum_hex);
break;
}
}
// When enabled, the first Fsync is to ensure all files are fully persisted
// before renaming CURRENT.tmp
if (io_s.ok() && db_dir_for_fsync) {
ROCKS_LOG_INFO(options_.info_log, "Restore: fsync\n");
io_s = db_dir_for_fsync->Fsync(io_options_, nullptr);
}
if (io_s.ok() && wal_dir_for_fsync) {
io_s = wal_dir_for_fsync->Fsync(io_options_, nullptr);
}
if (io_s.ok() && !temporary_current_file.empty()) {
ROCKS_LOG_INFO(options_.info_log, "Restore: atomic rename CURRENT.tmp\n");
assert(!final_current_file.empty());
io_s = db_fs_->RenameFile(temporary_current_file, final_current_file,
io_options_, nullptr);
}
if (io_s.ok() && db_dir_for_fsync && !temporary_current_file.empty()) {
// Second Fsync is to ensure the final atomic rename of DB restore is
// fully persisted even if power goes out right after restore operation
// returns success
assert(db_dir_for_fsync);
io_s = db_dir_for_fsync->Fsync(io_options_, nullptr);
}
ROCKS_LOG_INFO(options_.info_log, "Restoring done -- %s\n",
io_s.ToString().c_str());
return io_s;
}
IOStatus BackupEngineImpl::VerifyBackup(BackupID backup_id,
bool verify_with_checksum) const {
assert(initialized_);
// Check if backup_id is corrupted, or valid and registered
auto corrupt_itr = corrupt_backups_.find(backup_id);
if (corrupt_itr != corrupt_backups_.end()) {
return corrupt_itr->second.first;
}
auto backup_itr = backups_.find(backup_id);
if (backup_itr == backups_.end()) {
return IOStatus::NotFound();
}
auto& backup = backup_itr->second;
if (backup->Empty()) {
return IOStatus::NotFound();
}
ROCKS_LOG_INFO(options_.info_log, "Verifying backup id %u\n", backup_id);
// Find all existing backup files belong to backup_id
std::unordered_map<std::string, uint64_t> curr_abs_path_to_size;
for (const auto& rel_dir : {GetPrivateFileRel(backup_id), GetSharedFileRel(),
GetSharedFileWithChecksumRel()}) {
const auto abs_dir = GetAbsolutePath(rel_dir);
// Shared directories allowed to be missing in some cases. Expected but
// missing files will be reported a few lines down.
ReadChildFileCurrentSizes(abs_dir, backup_fs_, &curr_abs_path_to_size)
.PermitUncheckedError();
}
// For all files registered in backup
for (const auto& file_info : backup->GetFiles()) {
const auto abs_path = GetAbsolutePath(file_info->filename);
// check existence of the file
if (curr_abs_path_to_size.find(abs_path) == curr_abs_path_to_size.end()) {
return IOStatus::NotFound("File missing: " + abs_path);
}
// verify file size
if (file_info->size != curr_abs_path_to_size[abs_path]) {
std::string size_info("Expected file size is " +
ToString(file_info->size) +
" while found file size is " +
ToString(curr_abs_path_to_size[abs_path]));
return IOStatus::Corruption("File corrupted: File size mismatch for " +
abs_path + ": " + size_info);
}
if (verify_with_checksum && !file_info->checksum_hex.empty()) {
// verify file checksum
std::string checksum_hex;
ROCKS_LOG_INFO(options_.info_log, "Verifying %s checksum...\n",
abs_path.c_str());
IOStatus io_s =
ReadFileAndComputeChecksum(abs_path, backup_fs_, EnvOptions(),
0 /* size_limit */, &checksum_hex);
if (!io_s.ok()) {
return io_s;
} else if (file_info->checksum_hex != checksum_hex) {
std::string checksum_info(
"Expected checksum is " + file_info->checksum_hex +
" while computed checksum is " + checksum_hex);
return IOStatus::Corruption("File corrupted: Checksum mismatch for " +
abs_path + ": " + checksum_info);
}
}
}
return IOStatus::OK();
}
IOStatus BackupEngineImpl::CopyOrCreateFile(
const std::string& src, const std::string& dst, const std::string& contents,
uint64_t size_limit, Env* src_env, Env* dst_env,
const EnvOptions& src_env_options, bool sync, RateLimiter* rate_limiter,
std::function<void()> progress_callback,
uint64_t* bytes_toward_next_callback, uint64_t* size,
std::string* checksum_hex) {
assert(src.empty() != contents.empty());
IOStatus io_s;
std::unique_ptr<FSWritableFile> dst_file;
std::unique_ptr<FSSequentialFile> src_file;
FileOptions dst_file_options;
dst_file_options.use_mmap_writes = false;
// TODO:(gzh) maybe use direct reads/writes here if possible
if (size != nullptr) {
*size = 0;
}
uint32_t checksum_value = 0;
// Check if size limit is set. if not, set it to very big number
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
io_s = dst_env->GetFileSystem()->NewWritableFile(dst, dst_file_options,
&dst_file, nullptr);
if (io_s.ok() && !src.empty()) {
io_s = src_env->GetFileSystem()->NewSequentialFile(
src, FileOptions(src_env_options), &src_file, nullptr);
}
if (!io_s.ok()) {
return io_s;
}
size_t buf_size =
rate_limiter ? static_cast<size_t>(rate_limiter->GetSingleBurstBytes())
: kDefaultCopyFileBufferSize;
std::unique_ptr<WritableFileWriter> dest_writer(
new WritableFileWriter(std::move(dst_file), dst, dst_file_options));
std::unique_ptr<SequentialFileReader> src_reader;
std::unique_ptr<char[]> buf;
if (!src.empty()) {
src_reader.reset(new SequentialFileReader(std::move(src_file), src));
buf.reset(new char[buf_size]);
}
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return status_to_io_status(Status::Incomplete("Backup stopped"));
}
if (!src.empty()) {
size_t buffer_to_read =
(buf_size < size_limit) ? buf_size : static_cast<size_t>(size_limit);
io_s = src_reader->Read(buffer_to_read, &data, buf.get());
if (rate_limiter != nullptr) {
rate_limiter->Request(data.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
*bytes_toward_next_callback += data.size();
} else {
data = contents;
}
size_limit -= data.size();
TEST_SYNC_POINT_CALLBACK(
"BackupEngineImpl::CopyOrCreateFile:CorruptionDuringBackup",
(src.length() > 4 && src.rfind(".sst") == src.length() - 4) ? &data
: nullptr);
if (!io_s.ok()) {
return io_s;
}
if (size != nullptr) {
*size += data.size();
}
if (checksum_hex != nullptr) {
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
}
io_s = dest_writer->Append(data);
if (rate_limiter != nullptr) {
rate_limiter->Request(data.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kWrite);
}
while (*bytes_toward_next_callback >=
options_.callback_trigger_interval_size) {
*bytes_toward_next_callback -= options_.callback_trigger_interval_size;
std::lock_guard<std::mutex> lock(byte_report_mutex_);
progress_callback();
}
} while (io_s.ok() && contents.empty() && data.size() > 0 && size_limit > 0);
// Convert uint32_t checksum to hex checksum
if (checksum_hex != nullptr) {
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
}
if (io_s.ok() && sync) {
io_s = dest_writer->Sync(false);
}
if (io_s.ok()) {
io_s = dest_writer->Close();
}
return io_s;
}
// fname will always start with "/"
IOStatus BackupEngineImpl::AddBackupFileWorkItem(
std::unordered_set<std::string>& live_dst_paths,
std::vector<BackupAfterCopyOrCreateWorkItem>& backup_items_to_finish,
BackupID backup_id, bool shared, const std::string& src_dir,
const std::string& fname, const EnvOptions& src_env_options,
RateLimiter* rate_limiter, FileType file_type, uint64_t size_bytes,
Statistics* stats, uint64_t size_limit, bool shared_checksum,
std::function<void()> progress_callback, const std::string& contents,
const std::string& src_checksum_func_name,
const std::string& src_checksum_str) {
assert(contents.empty() != src_dir.empty());
std::string src_path = src_dir + "/" + fname;
std::string dst_relative;
std::string dst_relative_tmp;
std::string db_id;
std::string db_session_id;
// crc32c checksum in hex. empty == unavailable / unknown
std::string checksum_hex;
// Whenever a default checksum function name is passed in, we will compares
// the corresponding checksum values after copying. Note that only table and
// blob files may have a known checksum function name passed in.
//
// If no default checksum function name is passed in and db session id is not
// available, we will calculate the checksum *before* copying in two cases
// (we always calcuate checksums when copying or creating for any file types):
// a) share_files_with_checksum is true and file type is table;
// b) share_table_files is true and the file exists already.
//
// Step 0: Check if default checksum function name is passed in
if (kDbFileChecksumFuncName == src_checksum_func_name) {
if (src_checksum_str == kUnknownFileChecksum) {
return status_to_io_status(
Status::Aborted("Unknown checksum value for " + fname));
}
checksum_hex = ChecksumStrToHex(src_checksum_str);
}
// Step 1: Prepare the relative path to destination
if (shared && shared_checksum) {
if (GetNamingNoFlags() != BackupEngineOptions::kLegacyCrc32cAndFileSize &&
file_type != kBlobFile) {
// Prepare db_session_id to add to the file name
// Ignore the returned status
// In the failed cases, db_id and db_session_id will be empty
GetFileDbIdentities(db_env_, src_env_options, src_path, rate_limiter,
&db_id, &db_session_id)
.PermitUncheckedError();
}
// Calculate checksum if checksum and db session id are not available.
// If db session id is available, we will not calculate the checksum
// since the session id should suffice to avoid file name collision in
// the shared_checksum directory.
if (checksum_hex.empty() && db_session_id.empty()) {
IOStatus io_s = ReadFileAndComputeChecksum(
src_path, db_fs_, src_env_options, size_limit, &checksum_hex);
if (!io_s.ok()) {
return io_s;
}
}
if (size_bytes == port::kMaxUint64) {
return IOStatus::NotFound("File missing: " + src_path);
}
// dst_relative depends on the following conditions:
// 1) the naming scheme is kUseDbSessionId,
// 2) db_session_id is not empty,
// 3) checksum is available in the DB manifest.
// If 1,2,3) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<checksum>_<db_session_id>.sst
// If 1,2) are satisfied, then dst_relative will be of the form:
// shared_checksum/<file_number>_<db_session_id>.sst
// Otherwise, dst_relative is of the form
// shared_checksum/<file_number>_<checksum>_<size>.sst
//
// For blob files, db_session_id is not supported with the blob file format.
// It uses original/legacy naming scheme.
// dst_relative will be of the form:
// shared_checksum/<file_number>_<checksum>_<size>.blob
dst_relative = GetSharedFileWithChecksum(fname, checksum_hex, size_bytes,
db_session_id);
dst_relative_tmp = GetSharedFileWithChecksumRel(dst_relative, true);
dst_relative = GetSharedFileWithChecksumRel(dst_relative, false);
} else if (shared) {
dst_relative_tmp = GetSharedFileRel(fname, true);
dst_relative = GetSharedFileRel(fname, false);
} else {
dst_relative = GetPrivateFileRel(backup_id, false, fname);
}
// We copy into `temp_dest_path` and, once finished, rename it to
// `final_dest_path`. This allows files to atomically appear at
// `final_dest_path`. We can copy directly to the final path when atomicity
// is unnecessary, like for files in private backup directories.
const std::string* copy_dest_path;
std::string temp_dest_path;
std::string final_dest_path = GetAbsolutePath(dst_relative);
if (!dst_relative_tmp.empty()) {
temp_dest_path = GetAbsolutePath(dst_relative_tmp);
copy_dest_path = &temp_dest_path;
} else {
copy_dest_path = &final_dest_path;
}
// Step 2: Determine whether to copy or not
// if it's shared, we also need to check if it exists -- if it does, no need
// to copy it again.
bool need_to_copy = true;
// true if final_dest_path is the same path as another live file
const bool same_path =
live_dst_paths.find(final_dest_path) != live_dst_paths.end();
bool file_exists = false;
if (shared && !same_path) {
// Should be in shared directory but not a live path, check existence in
// shared directory
IOStatus exist =
backup_fs_->FileExists(final_dest_path, io_options_, nullptr);
if (exist.ok()) {
file_exists = true;
} else if (exist.IsNotFound()) {
file_exists = false;
} else {
return exist;
}
}
if (!contents.empty()) {
need_to_copy = false;
} else if (shared && (same_path || file_exists)) {
need_to_copy = false;
auto find_result = backuped_file_infos_.find(dst_relative);
if (find_result == backuped_file_infos_.end() && !same_path) {
// file exists but not referenced
ROCKS_LOG_INFO(
options_.info_log,
"%s already present, but not referenced by any backup. We will "
"overwrite the file.",
fname.c_str());
need_to_copy = true;
// Defer any failure reporting to when we try to write the file
backup_fs_->DeleteFile(final_dest_path, io_options_, nullptr)
.PermitUncheckedError();
} else {
// file exists and referenced
if (checksum_hex.empty()) {
// same_path should not happen for a standard DB, so OK to
// read file contents to check for checksum mismatch between
// two files from same DB getting same name.
// For compatibility with future meta file that might not have
// crc32c checksum available, consider it might be empty, but
// we don't currently generate meta file without crc32c checksum.
// Therefore we have to read & compute it if we don't have it.
if (!same_path && !find_result->second->checksum_hex.empty()) {
assert(find_result != backuped_file_infos_.end());
// Note: to save I/O on incremental backups, we copy prior known
// checksum of the file instead of reading entire file contents
// to recompute it.
checksum_hex = find_result->second->checksum_hex;
// Regarding corruption detection, consider:
// (a) the DB file is corrupt (since previous backup) and the backup
// file is OK: we failed to detect, but the backup is safe. DB can
// be repaired/restored once its corruption is detected.
// (b) the backup file is corrupt (since previous backup) and the
// db file is OK: we failed to detect, but the backup is corrupt.
// CreateNewBackup should support fast incremental backups and
// there's no way to support that without reading all the files.
// We might add an option for extra checks on incremental backup,
// but until then, use VerifyBackups to check existing backup data.
// (c) file name collision with legitimately different content.
// This is almost inconceivable with a well-generated DB session
// ID, but even in that case, we double check the file sizes in
// BackupMeta::AddFile.
} else {
IOStatus io_s = ReadFileAndComputeChecksum(
src_path, db_fs_, src_env_options, size_limit, &checksum_hex);
if (!io_s.ok()) {
return io_s;
}
}
}
if (!db_session_id.empty()) {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s, size %" PRIu64
" and DB session identity %s",
fname.c_str(), checksum_hex.c_str(), size_bytes,
db_session_id.c_str());
} else {
ROCKS_LOG_INFO(options_.info_log,
"%s already present, with checksum %s and size %" PRIu64,
fname.c_str(), checksum_hex.c_str(), size_bytes);
}
}
}
live_dst_paths.insert(final_dest_path);
// Step 3: Add work item
if (!contents.empty() || need_to_copy) {
ROCKS_LOG_INFO(options_.info_log, "Copying %s to %s", fname.c_str(),
copy_dest_path->c_str());
CopyOrCreateWorkItem copy_or_create_work_item(
src_dir.empty() ? "" : src_path, *copy_dest_path, contents, db_env_,
backup_env_, src_env_options, options_.sync, rate_limiter, size_limit,
stats, progress_callback, src_checksum_func_name, checksum_hex, db_id,
db_session_id);
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
copy_or_create_work_item.result.get_future(), shared, need_to_copy,
backup_env_, temp_dest_path, final_dest_path, dst_relative);
files_to_copy_or_create_.write(std::move(copy_or_create_work_item));
backup_items_to_finish.push_back(std::move(after_copy_or_create_work_item));
} else {
std::promise<CopyOrCreateResult> promise_result;
BackupAfterCopyOrCreateWorkItem after_copy_or_create_work_item(
promise_result.get_future(), shared, need_to_copy, backup_env_,
temp_dest_path, final_dest_path, dst_relative);
backup_items_to_finish.push_back(std::move(after_copy_or_create_work_item));
CopyOrCreateResult result;
result.io_status = IOStatus::OK();
result.size = size_bytes;
result.checksum_hex = std::move(checksum_hex);
result.db_id = std::move(db_id);
result.db_session_id = std::move(db_session_id);
promise_result.set_value(std::move(result));
}
return IOStatus::OK();
}
IOStatus BackupEngineImpl::ReadFileAndComputeChecksum(
const std::string& src, const std::shared_ptr<FileSystem>& src_fs,
const EnvOptions& src_env_options, uint64_t size_limit,
std::string* checksum_hex) const {
if (checksum_hex == nullptr) {
return status_to_io_status(Status::Aborted("Checksum pointer is null"));
}
uint32_t checksum_value = 0;
if (size_limit == 0) {
size_limit = std::numeric_limits<uint64_t>::max();
}
std::unique_ptr<SequentialFileReader> src_reader;
IOStatus io_s = SequentialFileReader::Create(
src_fs, src, FileOptions(src_env_options), &src_reader, nullptr);
if (!io_s.ok()) {
return io_s;
}
RateLimiter* rate_limiter = options_.backup_rate_limiter.get();
size_t buf_size =
rate_limiter ? static_cast<size_t>(rate_limiter->GetSingleBurstBytes())
: kDefaultCopyFileBufferSize;
std::unique_ptr<char[]> buf(new char[buf_size]);
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return status_to_io_status(Status::Incomplete("Backup stopped"));
}
size_t buffer_to_read =
(buf_size < size_limit) ? buf_size : static_cast<size_t>(size_limit);
io_s = src_reader->Read(buffer_to_read, &data, buf.get());
if (rate_limiter != nullptr) {
rate_limiter->Request(data.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
if (!io_s.ok()) {
return io_s;
}
size_limit -= data.size();
checksum_value = crc32c::Extend(checksum_value, data.data(), data.size());
} while (data.size() > 0 && size_limit > 0);
checksum_hex->assign(ChecksumInt32ToHex(checksum_value));
return io_s;
}
Status BackupEngineImpl::GetFileDbIdentities(Env* src_env,
const EnvOptions& src_env_options,
const std::string& file_path,
RateLimiter* rate_limiter,
std::string* db_id,
std::string* db_session_id) {
assert(db_id != nullptr || db_session_id != nullptr);
Options options;
options.env = src_env;
SstFileDumper sst_reader(options, file_path,
2 * 1024 * 1024
/* readahead_size */,
false /* verify_checksum */, false /* output_hex */,
false /* decode_blob_index */, src_env_options,
true /* silent */);
const TableProperties* table_properties = nullptr;
std::shared_ptr<const TableProperties> tp;
Status s = sst_reader.getStatus();
if (s.ok()) {
// Try to get table properties from the table reader of sst_reader
if (!sst_reader.ReadTableProperties(&tp).ok()) {
// Try to use table properites from the initialization of sst_reader
table_properties = sst_reader.GetInitTableProperties();
} else {
table_properties = tp.get();
if (table_properties != nullptr && rate_limiter != nullptr) {
// sizeof(*table_properties) is a sufficent but far-from-exact
// approximation of read bytes due to metaindex block, std::string
// properties and varint compression
rate_limiter->Request(sizeof(*table_properties), Env::IO_LOW,
nullptr /* stats */, RateLimiter::OpType::kRead);
}
}
} else {
ROCKS_LOG_INFO(options_.info_log, "Failed to read %s: %s",
file_path.c_str(), s.ToString().c_str());
return s;
}
if (table_properties != nullptr) {
if (db_id != nullptr) {
db_id->assign(table_properties->db_id);
}
if (db_session_id != nullptr) {
db_session_id->assign(table_properties->db_session_id);
if (db_session_id->empty()) {
s = Status::NotFound("DB session identity not found in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
return Status::OK();
} else {
s = Status::Corruption("Table properties missing in " + file_path);
ROCKS_LOG_INFO(options_.info_log, "%s", s.ToString().c_str());
return s;
}
}
void BackupEngineImpl::DeleteChildren(const std::string& dir,
uint32_t file_type_filter) const {
std::vector<std::string> children;
db_fs_->GetChildren(dir, io_options_, &children, nullptr)
.PermitUncheckedError(); // ignore errors
for (const auto& f : children) {
uint64_t number;
FileType type;
bool ok = ParseFileName(f, &number, &type);
if (ok && (file_type_filter & (1 << type))) {
// don't delete this file
continue;
}
db_fs_->DeleteFile(dir + "/" + f, io_options_, nullptr)
.PermitUncheckedError(); // ignore errors
}
}
IOStatus BackupEngineImpl::ReadChildFileCurrentSizes(
const std::string& dir, const std::shared_ptr<FileSystem>& fs,
std::unordered_map<std::string, uint64_t>* result) const {
assert(result != nullptr);
std::vector<Env::FileAttributes> files_attrs;
IOStatus io_status = fs->FileExists(dir, io_options_, nullptr);
if (io_status.ok()) {
io_status =
fs->GetChildrenFileAttributes(dir, io_options_, &files_attrs, nullptr);
} else if (io_status.IsNotFound()) {
// Insert no entries can be considered success
io_status = IOStatus::OK();
}
const bool slash_needed = dir.empty() || dir.back() != '/';
for (const auto& file_attrs : files_attrs) {
result->emplace(dir + (slash_needed ? "/" : "") + file_attrs.name,
file_attrs.size_bytes);
}
return io_status;
}
IOStatus BackupEngineImpl::GarbageCollect() {
assert(!read_only_);
// We will make a best effort to remove all garbage even in the presence
// of inconsistencies or I/O failures that inhibit finding garbage.
IOStatus overall_status = IOStatus::OK();
// If all goes well, we don't need another auto-GC this session
might_need_garbage_collect_ = false;
ROCKS_LOG_INFO(options_.info_log, "Starting garbage collection");
// delete obsolete shared files
for (bool with_checksum : {false, true}) {
std::vector<std::string> shared_children;
{
std::string shared_path;
if (with_checksum) {
shared_path = GetAbsolutePath(GetSharedFileWithChecksumRel());
} else {
shared_path = GetAbsolutePath(GetSharedFileRel());
}
IOStatus io_s = backup_fs_->FileExists(shared_path, io_options_, nullptr);
if (io_s.ok()) {
io_s = backup_fs_->GetChildren(shared_path, io_options_,
&shared_children, nullptr);
} else if (io_s.IsNotFound()) {
io_s = IOStatus::OK();
}
if (!io_s.ok()) {
overall_status = io_s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : shared_children) {
std::string rel_fname;
if (with_checksum) {
rel_fname = GetSharedFileWithChecksumRel(child);
} else {
rel_fname = GetSharedFileRel(child);
}
auto child_itr = backuped_file_infos_.find(rel_fname);
// if it's not refcounted, delete it
if (child_itr == backuped_file_infos_.end() ||
child_itr->second->refs == 0) {
// this might be a directory, but DeleteFile will just fail in that
// case, so we're good
IOStatus io_s = backup_fs_->DeleteFile(GetAbsolutePath(rel_fname),
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
rel_fname.c_str(), io_s.ToString().c_str());
backuped_file_infos_.erase(rel_fname);
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
}
// delete obsolete private files
std::vector<std::string> private_children;
{
IOStatus io_s =
backup_fs_->GetChildren(GetAbsolutePath(kPrivateDirName), io_options_,
&private_children, nullptr);
if (!io_s.ok()) {
overall_status = io_s;
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
for (auto& child : private_children) {
BackupID backup_id = 0;
bool tmp_dir = child.find(".tmp") != std::string::npos;
sscanf(child.c_str(), "%u", &backup_id);
if (!tmp_dir && // if it's tmp_dir, delete it
(backup_id == 0 || backups_.find(backup_id) != backups_.end())) {
// it's either not a number or it's still alive. continue
continue;
}
// here we have to delete the dir and all its children
std::string full_private_path =
GetAbsolutePath(GetPrivateFileRel(backup_id));
std::vector<std::string> subchildren;
if (backup_fs_
->GetChildren(full_private_path, io_options_, &subchildren, nullptr)
.ok()) {
for (auto& subchild : subchildren) {
IOStatus io_s = backup_fs_->DeleteFile(full_private_path + subchild,
io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting %s -- %s",
(full_private_path + subchild).c_str(),
io_s.ToString().c_str());
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
}
// finally delete the private dir
IOStatus io_s =
backup_fs_->DeleteDir(full_private_path, io_options_, nullptr);
ROCKS_LOG_INFO(options_.info_log, "Deleting dir %s -- %s",
full_private_path.c_str(), io_s.ToString().c_str());
if (!io_s.ok()) {
// Trying again later might work
might_need_garbage_collect_ = true;
}
}
assert(overall_status.ok() || might_need_garbage_collect_);
return overall_status;
}
// ------- BackupMeta class --------
IOStatus BackupEngineImpl::BackupMeta::AddFile(
std::shared_ptr<FileInfo> file_info) {
auto itr = file_infos_->find(file_info->filename);
if (itr == file_infos_->end()) {
auto ret = file_infos_->insert({file_info->filename, file_info});
if (ret.second) {
itr = ret.first;
itr->second->refs = 1;
} else {
// if this happens, something is seriously wrong
return IOStatus::Corruption("In memory metadata insertion error");
}
} else {
// Compare sizes, because we scanned that off the filesystem on both
// ends. This is like a check in VerifyBackup.
if (itr->second->size != file_info->size) {
std::string msg = "Size mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Size in backup is " + ToString(itr->second->size) +
" while size in DB is " + ToString(file_info->size));
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return IOStatus::Corruption(msg);
}
if (file_info->checksum_hex.empty()) {
// No checksum available to check
} else if (itr->second->checksum_hex.empty()) {
// Remember checksum if newly acquired
itr->second->checksum_hex = file_info->checksum_hex;
} else if (itr->second->checksum_hex != file_info->checksum_hex) {
// Note: to save I/O, these will be equal trivially on already backed
// up files that don't have the checksum in their name. And it should
// never fail for files that do have checksum in their name.
// Should never reach here, but produce an appropriate corruption
// message in case we do in a release build.
assert(false);
std::string msg = "Checksum mismatch for existing backup file: ";
msg.append(file_info->filename);
msg.append(" Expected checksum is " + itr->second->checksum_hex +
" while computed checksum is " + file_info->checksum_hex);
msg.append(
" If this DB file checks as not corrupt, try deleting old"
" backups or backing up to a different backup directory.");
return IOStatus::Corruption(msg);
}
++itr->second->refs; // increase refcount if already present
}
size_ += file_info->size;
files_.push_back(itr->second);
return IOStatus::OK();
}
IOStatus BackupEngineImpl::BackupMeta::Delete(bool delete_meta) {
IOStatus io_s;
for (const auto& file : files_) {
--file->refs; // decrease refcount
}
files_.clear();
// delete meta file
if (delete_meta) {
io_s = fs_->FileExists(meta_filename_, iooptions_, nullptr);
if (io_s.ok()) {
io_s = fs_->DeleteFile(meta_filename_, iooptions_, nullptr);
} else if (io_s.IsNotFound()) {
io_s = IOStatus::OK(); // nothing to delete
}
}
timestamp_ = 0;
return io_s;
}
// Constants for backup meta file schema (see LoadFromFile)
namespace {
const std::string kSchemaVersionPrefix{"schema_version "};
const std::string kFooterMarker{"// FOOTER"};
const std::string kAppMetaDataFieldName{"metadata"};
// WART: The checksums are crc32c but named "crc32"
const std::string kFileCrc32cFieldName{"crc32"};
const std::string kFileSizeFieldName{"size"};
// Marks a (future) field that should cause failure if not recognized.
// Other fields are assumed to be ignorable. For example, in the future
// we might add
// ni::file_name_escape uri_percent
// to indicate all file names have had spaces and special characters
// escaped using a URI percent encoding.
const std::string kNonIgnorableFieldPrefix{"ni::"};
} // namespace
// Each backup meta file is of the format (schema version 1):
//----------------------------------------------------------
// <timestamp>
// <seq number>
// metadata <metadata> (optional)
// <number of files>
// <file1> crc32 <crc32c_as_unsigned_decimal>
// <file2> crc32 <crc32c_as_unsigned_decimal>
// ...
//----------------------------------------------------------
//
// For schema version 2.x (not in public APIs, but
// forward-compatibility started):
//----------------------------------------------------------
// schema_version <ver>
// <timestamp>
// <seq number>
// [<field name> <field data>]
// ...
// <number of files>
// <file1>( <field name> <field data no spaces>)*
// <file2>( <field name> <field data no spaces>)*
// ...
// [// FOOTER]
// [<field name> <field data>]
// ...
//----------------------------------------------------------
// where
// <ver> ::= [0-9]+([.][0-9]+)
// <field name> ::= [A-Za-z_][A-Za-z_0-9.]+
// <field data> is anything but newline
// <field data no spaces> is anything but space and newline
// Although "// FOOTER" wouldn't strictly be required as a delimiter
// given the number of files is included, it is there for parsing
// sanity in case of corruption. It is only required if followed
// by footer fields, such as a checksum of the meta file (so far).
// Unrecognized fields are ignored, to support schema evolution on
// non-critical features with forward compatibility. Update schema
// major version for breaking changes. Schema minor versions are indicated
// only for diagnostic/debugging purposes.
//
// Fields in schema version 2.0:
// * Top-level meta fields:
// * Only "metadata" as in schema version 1
// * File meta fields:
// * "crc32" - a crc32c checksum as in schema version 1
// * "size" - the size of the file (new)
// * Footer meta fields:
// * None yet (future use for meta file checksum anticipated)
//
IOStatus BackupEngineImpl::BackupMeta::LoadFromFile(
const std::string& backup_dir,
const std::unordered_map<std::string, uint64_t>& abs_path_to_size,
RateLimiter* rate_limiter, Logger* info_log,
std::unordered_set<std::string>* reported_ignored_fields) {
assert(reported_ignored_fields);
assert(Empty());
std::unique_ptr<LineFileReader> backup_meta_reader;
{
IOStatus io_s = LineFileReader::Create(fs_, meta_filename_, FileOptions(),
&backup_meta_reader, nullptr);
if (!io_s.ok()) {
return io_s;
}
}
// If we don't read an explicit schema_version, that implies version 1,
// which is what we call the original backup meta schema.
int schema_major_version = 1;
// Failures handled at the end
std::string line;
if (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
if (StartsWith(line, kSchemaVersionPrefix)) {
std::string ver = line.substr(kSchemaVersionPrefix.size());
if (ver == "2" || StartsWith(ver, "2.")) {
schema_major_version = 2;
} else {
return IOStatus::NotSupported(
"Unsupported/unrecognized schema version: " + ver);
}
line.clear();
} else if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
}
if (!line.empty()) {
timestamp_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
} else if (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
timestamp_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
}
if (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
sequence_number_ = std::strtoull(line.c_str(), nullptr, /*base*/ 10);
}
uint32_t num_files = UINT32_MAX;
while (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
// Number -> number of files -> exit loop reading optional meta fields
if (line[0] >= '0' && line[0] <= '9') {
num_files = static_cast<uint32_t>(strtoul(line.c_str(), nullptr, 10));
break;
}
// else, must be a meta field assignment
auto space_pos = line.find_first_of(' ');
if (space_pos == std::string::npos) {
return IOStatus::Corruption("Expected number of files or meta field");
}
std::string field_name = line.substr(0, space_pos);
std::string field_data = line.substr(space_pos + 1);
if (field_name == kAppMetaDataFieldName) {
// app metadata present
bool decode_success = Slice(field_data).DecodeHex(&app_metadata_);
if (!decode_success) {
return IOStatus::Corruption(
"Failed to decode stored hex encoded app metadata");
}
} else if (schema_major_version < 2) {
return IOStatus::Corruption("Expected number of files or \"" +
kAppMetaDataFieldName + "\" field");
} else if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable meta field " +
field_name + " (from future version?)");
} else {
// Warn the first time we see any particular unrecognized meta field
if (reported_ignored_fields->insert("meta:" + field_name).second) {
ROCKS_LOG_WARN(info_log, "Ignoring unrecognized backup meta field %s",
field_name.c_str());
}
}
}
std::vector<std::shared_ptr<FileInfo>> files;
bool footer_present = false;
while (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
std::vector<std::string> components = StringSplit(line, ' ');
if (components.size() < 1) {
return IOStatus::Corruption("Empty line instead of file entry.");
}
if (schema_major_version >= 2 && components.size() == 2 &&
line == kFooterMarker) {
footer_present = true;
break;
}
const std::string& filename = components[0];
uint64_t actual_size;
const std::shared_ptr<FileInfo> file_info = GetFile(filename);
if (file_info) {
actual_size = file_info->size;
} else {
std::string abs_path = backup_dir + "/" + filename;
auto e = abs_path_to_size.find(abs_path);
if (e == abs_path_to_size.end()) {
return IOStatus::Corruption(
"Pathname in meta file not found on disk: " + abs_path);
}
actual_size = e->second;
}
if (schema_major_version >= 2) {
if (components.size() % 2 != 1) {
return IOStatus::Corruption(
"Bad number of line components for file entry.");
}
} else {
// Check restricted original schema
if (components.size() < 3) {
return IOStatus::Corruption("File checksum is missing for " + filename +
" in " + meta_filename_);
}
if (components[1] != kFileCrc32cFieldName) {
return IOStatus::Corruption("Unknown checksum type for " + filename +
" in " + meta_filename_);
}
if (components.size() > 3) {
return IOStatus::Corruption("Extra data for entry " + filename +
" in " + meta_filename_);
}
}
std::string checksum_hex;
for (unsigned i = 1; i < components.size(); i += 2) {
const std::string& field_name = components[i];
const std::string& field_data = components[i + 1];
if (field_name == kFileCrc32cFieldName) {
uint32_t checksum_value =
static_cast<uint32_t>(strtoul(field_data.c_str(), nullptr, 10));
if (field_data != ROCKSDB_NAMESPACE::ToString(checksum_value)) {
return IOStatus::Corruption("Invalid checksum value for " + filename +
" in " + meta_filename_);
}
checksum_hex = ChecksumInt32ToHex(checksum_value);
} else if (field_name == kFileSizeFieldName) {
uint64_t ex_size =
std::strtoull(field_data.c_str(), nullptr, /*base*/ 10);
if (ex_size != actual_size) {
return IOStatus::Corruption(
"For file " + filename + " expected size " + ToString(ex_size) +
" but found size" + ToString(actual_size));
}
} else if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable file field " +
field_name + " (from future version?)");
} else {
// Warn the first time we see any particular unrecognized file field
if (reported_ignored_fields->insert("file:" + field_name).second) {
ROCKS_LOG_WARN(info_log, "Ignoring unrecognized backup file field %s",
field_name.c_str());
}
}
}
files.emplace_back(new FileInfo(filename, actual_size, checksum_hex));
}
if (footer_present) {
assert(schema_major_version >= 2);
while (backup_meta_reader->ReadLine(&line)) {
if (rate_limiter != nullptr) {
rate_limiter->Request(line.size(), Env::IO_LOW, nullptr /* stats */,
RateLimiter::OpType::kRead);
}
if (line.empty()) {
return IOStatus::Corruption("Unexpected empty line");
}
auto space_pos = line.find_first_of(' ');
if (space_pos == std::string::npos) {
return IOStatus::Corruption("Expected footer field");
}
std::string field_name = line.substr(0, space_pos);
std::string field_data = line.substr(space_pos + 1);
if (StartsWith(field_name, kNonIgnorableFieldPrefix)) {
return IOStatus::NotSupported("Unrecognized non-ignorable field " +
field_name + " (from future version?)");
} else if (reported_ignored_fields->insert("footer:" + field_name)
.second) {
// Warn the first time we see any particular unrecognized footer field
ROCKS_LOG_WARN(info_log,
"Ignoring unrecognized backup meta footer field %s",
field_name.c_str());
}
}
}
{
IOStatus io_s = backup_meta_reader->GetStatus();
if (!io_s.ok()) {
return io_s;
}
}
if (num_files != files.size()) {
return IOStatus::Corruption(
"Inconsistent number of files or missing/incomplete header in " +
meta_filename_);
}
files_.reserve(files.size());
for (const auto& file_info : files) {
IOStatus io_s = AddFile(file_info);
if (!io_s.ok()) {
return io_s;
}
}
return IOStatus::OK();
}
IOStatus BackupEngineImpl::BackupMeta::StoreToFile(
bool sync, const TEST_FutureSchemaVersion2Options* test_future_options) {
IOStatus io_s;
std::unique_ptr<FSWritableFile> backup_meta_file;
FileOptions file_options;
file_options.use_mmap_writes = false;
file_options.use_direct_writes = false;
io_s = fs_->NewWritableFile(meta_tmp_filename_, file_options,
&backup_meta_file, nullptr);
if (!io_s.ok()) {
return io_s;
}
std::ostringstream buf;
if (test_future_options) {
buf << kSchemaVersionPrefix << test_future_options->version << "\n";
}
buf << static_cast<unsigned long long>(timestamp_) << "\n";
buf << sequence_number_ << "\n";
if (!app_metadata_.empty()) {
std::string hex_encoded_metadata =
Slice(app_metadata_).ToString(/* hex */ true);
buf << kAppMetaDataFieldName << " " << hex_encoded_metadata << "\n";
}
if (test_future_options) {
for (auto& e : test_future_options->meta_fields) {
buf << e.first << " " << e.second << "\n";
}
}
buf << files_.size() << "\n";
for (const auto& file : files_) {
buf << file->filename;
if (test_future_options == nullptr ||
test_future_options->crc32c_checksums) {
// use crc32c for now, switch to something else if needed
buf << " " << kFileCrc32cFieldName << " "
<< ChecksumHexToInt32(file->checksum_hex);
}
if (test_future_options && test_future_options->file_sizes) {
buf << " " << kFileSizeFieldName << " " << ToString(file->size);
}
if (test_future_options) {
for (auto& e : test_future_options->file_fields) {
buf << " " << e.first << " " << e.second;
}
}
buf << "\n";
}
if (test_future_options && !test_future_options->footer_fields.empty()) {
buf << kFooterMarker << "\n";
for (auto& e : test_future_options->footer_fields) {
buf << e.first << " " << e.second << "\n";
}
}
io_s = backup_meta_file->Append(Slice(buf.str()), iooptions_, nullptr);
IOSTATS_ADD(bytes_written, buf.str().size());
if (io_s.ok() && sync) {
io_s = backup_meta_file->Sync(iooptions_, nullptr);
}
if (io_s.ok()) {
io_s = backup_meta_file->Close(iooptions_, nullptr);
}
if (io_s.ok()) {
io_s = fs_->RenameFile(meta_tmp_filename_, meta_filename_, iooptions_,
nullptr);
}
return io_s;
}
IOStatus BackupEngineReadOnly::Open(const BackupEngineOptions& options,
Env* env,
BackupEngineReadOnly** backup_engine_ptr) {
if (options.destroy_old_data) {
return IOStatus::InvalidArgument(
"Can't destroy old data with ReadOnly BackupEngine");
}
std::unique_ptr<BackupEngineImplThreadSafe> backup_engine(
new BackupEngineImplThreadSafe(options, env, true /*read_only*/));
auto s = backup_engine->Initialize();
if (!s.ok()) {
*backup_engine_ptr = nullptr;
return s;
}
*backup_engine_ptr = backup_engine.release();
return IOStatus::OK();
}
void TEST_EnableWriteFutureSchemaVersion2(
BackupEngine* engine, const TEST_FutureSchemaVersion2Options& options) {
BackupEngineImplThreadSafe* impl =
static_cast_with_check<BackupEngineImplThreadSafe>(engine);
impl->TEST_EnableWriteFutureSchemaVersion2(options);
}
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE
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