andreacavalli/rocksdb
0
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Feature requests for BackupableDB

Browse Source 
Summary:
This diff introduces some features that were requested by two internal customers:
* Ability for backups not to share table files, because we can't guarantee that equal filename means equal content accross replicas
* Ability for two threads to call EnableFileDeletions() and DisableFileDeletions()
* Ability to stop backup from another thread and not slow down the DB close
* Copy the files to the temporary folder first and then atomically rename

Test Plan: Added some tests to backupable_db_test

Reviewers: dhruba, sanketh, muthu, sdong, haobo

Reviewed By: haobo

CC: leveldb, sanketh, muthu

Differential Revision: https://reviews.facebook.net/D14769
This commit is contained in:
Igor Canadi 2014-01-09 12:24:28 -08:00
parent d0406675c2
commit cb37ddf229
3 changed files with 112 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
include/utilities/backupable_db.h
View File

@ -31,6 +31,14 @@ struct BackupableDBOptions {
// Default: nullptr
Env* backup_env;
// If share_table_files == true, backup will assume that table files with
// same name have the same contents. This enables incremental backups and
// avoids unnecessary data copies.
// If share_table_files == false, each backup will be on its own and will
// not share any data with other backups.
// default: true
bool share_table_files;
// Backup info and error messages will be written to info_log
// if non-nullptr.
// Default: nullptr
@ -49,6 +57,7 @@ struct BackupableDBOptions {
explicit BackupableDBOptions(const std::string& _backup_dir,
Env* _backup_env = nullptr,
bool _share_table_files = true,
Logger* _info_log = nullptr,
bool _sync = true,
bool _destroy_old_data = false) :
@ -93,6 +102,14 @@ class BackupableDB : public StackableDB {
Status PurgeOldBackups(uint32_t num_backups_to_keep);
// deletes a specific backup
Status DeleteBackup(BackupID backup_id);
// Call this from another thread if you want to stop the backup
// that is currently happening. It will return immediatelly, will
// not wait for the backup to stop.
// The backup will stop ASAP and the call to CreateNewBackup will
// return Status::Incomplete(). It will not clean up after itself, but
// the state will remain consistent. The state will be cleaned up
// next time you create BackupableDB or RestoreBackupableDB.
void StopBackup();
private:
BackupEngine* backup_engine_;
@ -108,9 +125,10 @@ class RestoreBackupableDB {
void GetBackupInfo(std::vector<BackupInfo>* backup_info);
// restore from backup with backup_id
// IMPORTANT -- if you restore from some backup that is not the latest,
// and you start creating new backups from the new DB, all the backups
// that were newer than the backup you restored from will be deleted
// IMPORTANT -- if options_.share_table_files == true and you restore DB
// from some backup that is not the latest, and you start creating new
// backups from the new DB, all the backups that were newer than the
// backup you restored from will be deleted
//
// Example: Let's say you have backups 1, 2, 3, 4, 5 and you restore 3.
// If you try creating a new backup now, old backups 4 and 5 will be deleted

72
utilities/backupable/backupable_db.cc
View File

@ -20,6 +20,7 @@
#include <map>
#include <string>
#include <limits>
#include <atomic>
namespace rocksdb {
@ -31,6 +32,9 @@ class BackupEngine {
Status CreateNewBackup(DB* db, bool flush_before_backup = false);
Status PurgeOldBackups(uint32_t num_backups_to_keep);
Status DeleteBackup(BackupID backup_id);
void StopBackup() {
stop_backup_.store(true, std::memory_order_release);
}
void GetBackupInfo(std::vector<BackupInfo>* backup_info);
Status RestoreDBFromBackup(BackupID backup_id, const std::string &db_dir,
@ -106,13 +110,16 @@ class BackupEngine {
return "private";
}
inline std::string GetPrivateFileRel(BackupID backup_id,
const std::string &file = "") const {
bool tmp = false,
const std::string& file = "") const {
assert(file.size() == 0 || file[0] != '/');
return GetPrivateDirRel() + "/" + std::to_string(backup_id) + "/" + file;
return GetPrivateDirRel() + "/" + std::to_string(backup_id) +
(tmp ? ".tmp" : "") + "/" + file;
}
inline std::string GetSharedFileRel(const std::string& file = "") const {
inline std::string GetSharedFileRel(const std::string& file = "",
bool tmp = false) const {
assert(file.size() == 0 || file[0] != '/');
return "shared/" + file;
return "shared/" + file + (tmp ? ".tmp" : "");
}
inline std::string GetLatestBackupFile(bool tmp = false) const {
return GetAbsolutePath(std::string("LATEST_BACKUP") + (tmp ? ".tmp" : ""));
@ -151,6 +158,7 @@ class BackupEngine {
std::map<BackupID, BackupMeta> backups_;
std::unordered_map<std::string, int> backuped_file_refs_;
std::vector<BackupID> obsolete_backups_;
std::atomic<bool> stop_backup_;
// options data
BackupableDBOptions options_;
@ -161,13 +169,17 @@ class BackupEngine {
};
BackupEngine::BackupEngine(Env* db_env, const BackupableDBOptions& options)
: options_(options),
db_env_(db_env),
backup_env_(options.backup_env != nullptr ? options.backup_env : db_env_) {
: stop_backup_(false),
options_(options),
db_env_(db_env),
backup_env_(options.backup_env != nullptr ? options.backup_env
: db_env_) {
// create all the dirs we need
backup_env_->CreateDirIfMissing(GetAbsolutePath());
backup_env_->CreateDirIfMissing(GetAbsolutePath(GetSharedFileRel()));
if (!options_.share_table_files) {
backup_env_->CreateDirIfMissing(GetAbsolutePath(GetSharedFileRel()));
}
backup_env_->CreateDirIfMissing(GetAbsolutePath(GetPrivateDirRel()));
backup_env_->CreateDirIfMissing(GetBackupMetaDir());
@ -298,8 +310,9 @@ Status BackupEngine::CreateNewBackup(DB* db, bool flush_before_backup) {
Log(options_.info_log, "Started the backup process -- creating backup %u",
new_backup_id);
// create private dir
s = backup_env_->CreateDir(GetAbsolutePath(GetPrivateFileRel(new_backup_id)));
// create temporary private dir
s = backup_env_->CreateDir(
GetAbsolutePath(GetPrivateFileRel(new_backup_id, true)));
// copy live_files
for (size_t i = 0; s.ok() && i < live_files.size(); ++i) {
@ -320,7 +333,7 @@ Status BackupEngine::CreateNewBackup(DB* db, bool flush_before_backup) {
// * if it's kDescriptorFile, limit the size to manifest_file_size
s = BackupFile(new_backup_id,
&new_backup,
type == kTableFile, /* shared */
options_.share_table_files && type == kTableFile,
db->GetName(), /* src_dir */
live_files[i], /* src_fname */
(type == kDescriptorFile) ? manifest_file_size : 0);
@ -342,6 +355,13 @@ Status BackupEngine::CreateNewBackup(DB* db, bool flush_before_backup) {
// we copied all the files, enable file deletions
db->EnableFileDeletions();
if (s.ok()) {
// move tmp private backup to real backup folder
s = backup_env_->RenameFile(
GetAbsolutePath(GetPrivateFileRel(new_backup_id, true)), // tmp
GetAbsolutePath(GetPrivateFileRel(new_backup_id, false)));
}
if (s.ok()) {
// persist the backup metadata on the disk
s = new_backup.StoreToFile(options_.sync);
@ -561,6 +581,9 @@ Status BackupEngine::CopyFile(const std::string& src,
Slice data;
do {
if (stop_backup_.load(std::memory_order_acquire)) {
return Status::Incomplete("Backup stopped");
}
size_t buffer_to_read = (copy_file_buffer_size_ < size_limit) ?
copy_file_buffer_size_ : size_limit;
s = src_file->Read(buffer_to_read, &data, buf.get());
@ -590,12 +613,16 @@ Status BackupEngine::BackupFile(BackupID backup_id,
assert(src_fname.size() > 0 && src_fname[0] == '/');
std::string dst_relative = src_fname.substr(1);
std::string dst_relative_tmp;
if (shared) {
dst_relative = GetSharedFileRel(dst_relative);
dst_relative_tmp = GetSharedFileRel(dst_relative, true);
dst_relative = GetSharedFileRel(dst_relative, false);
} else {
dst_relative = GetPrivateFileRel(backup_id, dst_relative);
dst_relative_tmp = GetPrivateFileRel(backup_id, true, dst_relative);
dst_relative = GetPrivateFileRel(backup_id, false, dst_relative);
}
std::string dst_path = GetAbsolutePath(dst_relative);
std::string dst_path_tmp = GetAbsolutePath(dst_relative_tmp);
Status s;
uint64_t size;
@ -607,12 +634,15 @@ Status BackupEngine::BackupFile(BackupID backup_id,
} else {
Log(options_.info_log, "Copying %s", src_fname.c_str());
s = CopyFile(src_dir + src_fname,
dst_path,
dst_path_tmp,
db_env_,
backup_env_,
options_.sync,
&size,
size_limit);
if (s.ok() && shared) {
s = backup_env_->RenameFile(dst_path_tmp, dst_path);
}
}
if (s.ok()) {
backup->AddFile(dst_relative, size);
@ -671,14 +701,16 @@ void BackupEngine::GarbageCollection(bool full_scan) {
&private_children);
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 (backup_id == 0 || backups_.find(backup_id) != backups_.end()) {
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));
GetAbsolutePath(GetPrivateFileRel(backup_id, tmp_dir));
std::vector<std::string> subchildren;
backup_env_->GetChildren(full_private_path, &subchildren);
for (auto& subchild : subchildren) {
@ -813,7 +845,9 @@ Status BackupEngine::BackupMeta::StoreToFile(bool sync) {
BackupableDB::BackupableDB(DB* db, const BackupableDBOptions& options)
: StackableDB(db), backup_engine_(new BackupEngine(db->GetEnv(), options)) {
backup_engine_->DeleteBackupsNewerThan(GetLatestSequenceNumber());
if (options.share_table_files) {
backup_engine_->DeleteBackupsNewerThan(GetLatestSequenceNumber());
}
}
BackupableDB::~BackupableDB() {
@ -836,6 +870,10 @@ Status BackupableDB::DeleteBackup(BackupID backup_id) {
return backup_engine_->DeleteBackup(backup_id);
}
void BackupableDB::StopBackup() {
backup_engine_->StopBackup();
}
// --- RestoreBackupableDB methods ------
RestoreBackupableDB::RestoreBackupableDB(Env* db_env,

38
utilities/backupable/backupable_db_test.cc
View File

@ -305,7 +305,7 @@ class BackupableDBTest {
CreateLoggerFromOptions(dbname_, backupdir_, env_,
Options(), &logger_);
backupable_options_.reset(new BackupableDBOptions(
backupdir_, test_backup_env_.get(), logger_.get(), true));
backupdir_, test_backup_env_.get(), true, logger_.get(), true));
// delete old files in db
DestroyDB(dbname_, Options());
@ -317,7 +317,8 @@ class BackupableDBTest {
return db;
}
void OpenBackupableDB(bool destroy_old_data = false, bool dummy = false) {
void OpenBackupableDB(bool destroy_old_data = false, bool dummy = false,
bool share_table_files = true) {
// reset all the defaults
test_backup_env_->SetLimitWrittenFiles(1000000);
test_db_env_->SetLimitWrittenFiles(1000000);
@ -331,6 +332,7 @@ class BackupableDBTest {
ASSERT_OK(DB::Open(options_, dbname_, &db));
}
backupable_options_->destroy_old_data = destroy_old_data;
backupable_options_->share_table_files = share_table_files;
db_.reset(new BackupableDB(db, *backupable_options_));
}
@ -659,6 +661,38 @@ TEST(BackupableDBTest, DeleteNewerBackups) {
CloseRestoreDB();
}
TEST(BackupableDBTest, NoShareTableFiles) {
const int keys_iteration = 5000;
OpenBackupableDB(true, false, false);
for (int i = 0; i < 5; ++i) {
FillDB(db_.get(), keys_iteration * i, keys_iteration * (i + 1));
ASSERT_OK(db_->CreateNewBackup(!!(i % 2)));
}
CloseBackupableDB();
for (int i = 0; i < 5; ++i) {
AssertBackupConsistency(i + 1, 0, keys_iteration * (i + 1),
keys_iteration * 6);
}
}
TEST(BackupableDBTest, DeleteTmpFiles) {
OpenBackupableDB();
CloseBackupableDB();
std::string shared_tmp = backupdir_ + "/shared/00006.sst.tmp";
std::string private_tmp_dir = backupdir_ + "/private/10.tmp";
std::string private_tmp_file = private_tmp_dir + "/00003.sst";
file_manager_->WriteToFile(shared_tmp, "tmp");
file_manager_->CreateDir(private_tmp_dir);
file_manager_->WriteToFile(private_tmp_file, "tmp");
ASSERT_EQ(true, file_manager_->FileExists(private_tmp_dir));
OpenBackupableDB();
CloseBackupableDB();
ASSERT_EQ(false, file_manager_->FileExists(shared_tmp));
ASSERT_EQ(false, file_manager_->FileExists(private_tmp_file));
ASSERT_EQ(false, file_manager_->FileExists(private_tmp_dir));
}
} // anon namespace
} // namespace rocksdb