rocksdb/utilities/checkpoint/checkpoint_impl.cc
Zhichao Cao d8ec0a760a Make FileType Public and Replace kLogFile with kWalFile (#7580)
Summary:
As suggested by pdillinger ,The name of kLogFile is misleading, in some tests, kLogFile is defined as info log. Replace it with kWalFile and move it to public, which will be used in https://github.com/facebook/rocksdb/issues/7523

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7580

Test Plan: make check

Reviewed By: riversand963

Differential Revision: D24485420

Pulled By: zhichao-cao

fbshipit-source-id: 955e3dacc1021bb590fde93b0a568ffe9ad80799
2020-10-22 17:06:20 -07:00

584 lines
22 KiB
C++

// 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) 2012 Facebook.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ROCKSDB_LITE
#include "utilities/checkpoint/checkpoint_impl.h"
#include <algorithm>
#include <cinttypes>
#include <string>
#include <vector>
#include "db/wal_manager.h"
#include "file/file_util.h"
#include "file/filename.h"
#include "port/port.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/metadata.h"
#include "rocksdb/transaction_log.h"
#include "rocksdb/utilities/checkpoint.h"
#include "test_util/sync_point.h"
#include "util/cast_util.h"
#include "util/file_checksum_helper.h"
namespace ROCKSDB_NAMESPACE {
Status Checkpoint::Create(DB* db, Checkpoint** checkpoint_ptr) {
*checkpoint_ptr = new CheckpointImpl(db);
return Status::OK();
}
Status Checkpoint::CreateCheckpoint(const std::string& /*checkpoint_dir*/,
uint64_t /*log_size_for_flush*/,
uint64_t* /*sequence_number_ptr*/) {
return Status::NotSupported("");
}
void CheckpointImpl::CleanStagingDirectory(
const std::string& full_private_path, Logger* info_log) {
std::vector<std::string> subchildren;
Status s = db_->GetEnv()->FileExists(full_private_path);
if (s.IsNotFound()) {
return;
}
ROCKS_LOG_INFO(info_log, "File exists %s -- %s",
full_private_path.c_str(), s.ToString().c_str());
db_->GetEnv()->GetChildren(full_private_path, &subchildren);
for (auto& subchild : subchildren) {
std::string subchild_path = full_private_path + "/" + subchild;
s = db_->GetEnv()->DeleteFile(subchild_path);
ROCKS_LOG_INFO(info_log, "Delete file %s -- %s",
subchild_path.c_str(), s.ToString().c_str());
}
// finally delete the private dir
s = db_->GetEnv()->DeleteDir(full_private_path);
ROCKS_LOG_INFO(info_log, "Delete dir %s -- %s",
full_private_path.c_str(), s.ToString().c_str());
}
Status Checkpoint::ExportColumnFamily(
ColumnFamilyHandle* /*handle*/, const std::string& /*export_dir*/,
ExportImportFilesMetaData** /*metadata*/) {
return Status::NotSupported("");
}
// Builds an openable snapshot of RocksDB
Status CheckpointImpl::CreateCheckpoint(const std::string& checkpoint_dir,
uint64_t log_size_for_flush,
uint64_t* sequence_number_ptr) {
DBOptions db_options = db_->GetDBOptions();
Status s = db_->GetEnv()->FileExists(checkpoint_dir);
if (s.ok()) {
return Status::InvalidArgument("Directory exists");
} else if (!s.IsNotFound()) {
assert(s.IsIOError());
return s;
}
ROCKS_LOG_INFO(
db_options.info_log,
"Started the snapshot process -- creating snapshot in directory %s",
checkpoint_dir.c_str());
size_t final_nonslash_idx = checkpoint_dir.find_last_not_of('/');
if (final_nonslash_idx == std::string::npos) {
// npos means it's only slashes or empty. Non-empty means it's the root
// directory, but it shouldn't be because we verified above the directory
// doesn't exist.
assert(checkpoint_dir.empty());
return Status::InvalidArgument("invalid checkpoint directory name");
}
std::string full_private_path =
checkpoint_dir.substr(0, final_nonslash_idx + 1) + ".tmp";
ROCKS_LOG_INFO(
db_options.info_log,
"Snapshot process -- using temporary directory %s",
full_private_path.c_str());
CleanStagingDirectory(full_private_path, db_options.info_log.get());
// create snapshot directory
s = db_->GetEnv()->CreateDir(full_private_path);
uint64_t sequence_number = 0;
if (s.ok()) {
db_->DisableFileDeletions();
s = CreateCustomCheckpoint(
db_options,
[&](const std::string& src_dirname, const std::string& fname,
FileType) {
ROCKS_LOG_INFO(db_options.info_log, "Hard Linking %s", fname.c_str());
return db_->GetFileSystem()->LinkFile(src_dirname + fname,
full_private_path + fname,
IOOptions(), nullptr);
} /* link_file_cb */,
[&](const std::string& src_dirname, const std::string& fname,
uint64_t size_limit_bytes, FileType,
const std::string& /* checksum_func_name */,
const std::string& /* checksum_val */) {
ROCKS_LOG_INFO(db_options.info_log, "Copying %s", fname.c_str());
return CopyFile(db_->GetFileSystem(), src_dirname + fname,
full_private_path + fname, size_limit_bytes,
db_options.use_fsync);
} /* copy_file_cb */,
[&](const std::string& fname, const std::string& contents, FileType) {
ROCKS_LOG_INFO(db_options.info_log, "Creating %s", fname.c_str());
return CreateFile(db_->GetFileSystem(), full_private_path + fname,
contents, db_options.use_fsync);
} /* create_file_cb */,
&sequence_number, log_size_for_flush);
// we copied all the files, enable file deletions
db_->EnableFileDeletions(false);
}
if (s.ok()) {
// move tmp private backup to real snapshot directory
s = db_->GetEnv()->RenameFile(full_private_path, checkpoint_dir);
}
if (s.ok()) {
std::unique_ptr<Directory> checkpoint_directory;
db_->GetEnv()->NewDirectory(checkpoint_dir, &checkpoint_directory);
if (checkpoint_directory != nullptr) {
s = checkpoint_directory->Fsync();
}
}
if (s.ok()) {
if (sequence_number_ptr != nullptr) {
*sequence_number_ptr = sequence_number;
}
// here we know that we succeeded and installed the new snapshot
ROCKS_LOG_INFO(db_options.info_log, "Snapshot DONE. All is good");
ROCKS_LOG_INFO(db_options.info_log, "Snapshot sequence number: %" PRIu64,
sequence_number);
} else {
// clean all the files we might have created
ROCKS_LOG_INFO(db_options.info_log, "Snapshot failed -- %s",
s.ToString().c_str());
CleanStagingDirectory(full_private_path, db_options.info_log.get());
}
return s;
}
Status CheckpointImpl::CreateCustomCheckpoint(
const DBOptions& db_options,
std::function<Status(const std::string& src_dirname,
const std::string& src_fname, FileType type)>
link_file_cb,
std::function<Status(
const std::string& src_dirname, const std::string& src_fname,
uint64_t size_limit_bytes, FileType type,
const std::string& checksum_func_name, const std::string& checksum_val)>
copy_file_cb,
std::function<Status(const std::string& fname, const std::string& contents,
FileType type)>
create_file_cb,
uint64_t* sequence_number, uint64_t log_size_for_flush,
bool get_live_table_checksum) {
Status s;
std::vector<std::string> live_files;
uint64_t manifest_file_size = 0;
uint64_t min_log_num = port::kMaxUint64;
*sequence_number = db_->GetLatestSequenceNumber();
bool same_fs = true;
VectorLogPtr live_wal_files;
bool flush_memtable = true;
if (s.ok()) {
if (!db_options.allow_2pc) {
if (log_size_for_flush == port::kMaxUint64) {
flush_memtable = false;
} else if (log_size_for_flush > 0) {
// If out standing log files are small, we skip the flush.
s = db_->GetSortedWalFiles(live_wal_files);
if (!s.ok()) {
return s;
}
// Don't flush column families if total log size is smaller than
// log_size_for_flush. We copy the log files instead.
// We may be able to cover 2PC case too.
uint64_t total_wal_size = 0;
for (auto& wal : live_wal_files) {
total_wal_size += wal->SizeFileBytes();
}
if (total_wal_size < log_size_for_flush) {
flush_memtable = false;
}
live_wal_files.clear();
}
}
// this will return live_files prefixed with "/"
s = db_->GetLiveFiles(live_files, &manifest_file_size, flush_memtable);
if (s.ok() && db_options.allow_2pc) {
// If 2PC is enabled, we need to get minimum log number after the flush.
// Need to refetch the live files to recapture the snapshot.
if (!db_->GetIntProperty(DB::Properties::kMinLogNumberToKeep,
&min_log_num)) {
return Status::InvalidArgument(
"2PC enabled but cannot fine the min log number to keep.");
}
// We need to refetch live files with flush to handle this case:
// A previous 000001.log contains the prepare record of transaction tnx1.
// The current log file is 000002.log, and sequence_number points to this
// file.
// After calling GetLiveFiles(), 000003.log is created.
// Then tnx1 is committed. The commit record is written to 000003.log.
// Now we fetch min_log_num, which will be 3.
// Then only 000002.log and 000003.log will be copied, and 000001.log will
// be skipped. 000003.log contains commit message of tnx1, but we don't
// have respective prepare record for it.
// In order to avoid this situation, we need to force flush to make sure
// all transactions committed before getting min_log_num will be flushed
// to SST files.
// We cannot get min_log_num before calling the GetLiveFiles() for the
// first time, because if we do that, all the logs files will be included,
// far more than needed.
s = db_->GetLiveFiles(live_files, &manifest_file_size, flush_memtable);
}
TEST_SYNC_POINT("CheckpointImpl::CreateCheckpoint:SavedLiveFiles1");
TEST_SYNC_POINT("CheckpointImpl::CreateCheckpoint:SavedLiveFiles2");
db_->FlushWAL(false /* sync */);
}
TEST_SYNC_POINT("CheckpointImpl::CreateCustomCheckpoint:AfterGetLive1");
TEST_SYNC_POINT("CheckpointImpl::CreateCustomCheckpoint:AfterGetLive2");
// if we have more than one column family, we need to also get WAL files
if (s.ok()) {
s = db_->GetSortedWalFiles(live_wal_files);
}
if (!s.ok()) {
return s;
}
size_t wal_size = live_wal_files.size();
// process live files, non-table files first
std::string manifest_fname, current_fname;
// record table files for processing next
std::vector<std::pair<std::string, uint64_t>> live_table_files;
for (auto& live_file : live_files) {
if (!s.ok()) {
break;
}
uint64_t number;
FileType type;
bool ok = ParseFileName(live_file, &number, &type);
if (!ok) {
s = Status::Corruption("Can't parse file name. This is very bad");
break;
}
// we should only get sst, options, manifest and current files here
assert(type == kTableFile || type == kDescriptorFile ||
type == kCurrentFile || type == kOptionsFile);
assert(live_file.size() > 0 && live_file[0] == '/');
if (type == kCurrentFile) {
// We will craft the current file manually to ensure it's consistent with
// the manifest number. This is necessary because current's file contents
// can change during checkpoint creation.
current_fname = live_file;
continue;
} else if (type == kDescriptorFile) {
manifest_fname = live_file;
}
if (type != kTableFile) {
// copy non-table files here
// * if it's kDescriptorFile, limit the size to manifest_file_size
s = copy_file_cb(db_->GetName(), live_file,
(type == kDescriptorFile) ? manifest_file_size : 0, type,
kUnknownFileChecksumFuncName, kUnknownFileChecksum);
} else {
// process table files below
live_table_files.push_back(make_pair(live_file, number));
}
}
// get checksum info for table files
// get table file checksums if get_live_table_checksum is true
std::unique_ptr<FileChecksumList> checksum_list;
if (s.ok() && get_live_table_checksum) {
checksum_list.reset(NewFileChecksumList());
// should succeed even without checksum info present, else manifest
// is corrupt
s = GetFileChecksumsFromManifest(db_->GetEnv(),
db_->GetName() + manifest_fname,
manifest_file_size, checksum_list.get());
}
// copy/hard link live table files
for (auto& ltf : live_table_files) {
if (!s.ok()) {
break;
}
std::string& src_fname = ltf.first;
uint64_t number = ltf.second;
// rules:
// * for kTableFile, attempt hard link instead of copy.
// * but can't hard link across filesystems.
if (same_fs) {
s = link_file_cb(db_->GetName(), src_fname, kTableFile);
if (s.IsNotSupported()) {
same_fs = false;
s = Status::OK();
}
}
if (!same_fs) {
std::string checksum_name = kUnknownFileChecksumFuncName;
std::string checksum_value = kUnknownFileChecksum;
// we ignore the checksums either they are not required or we failed to
// obtain the checksum lsit for old table files that have no file
// checksums
if (get_live_table_checksum) {
// find checksum info for table files
Status search = checksum_list->SearchOneFileChecksum(
number, &checksum_value, &checksum_name);
// could be a legacy file lacking checksum info. overall OK if
// not found
if (!search.ok()) {
assert(checksum_name == kUnknownFileChecksumFuncName);
assert(checksum_value == kUnknownFileChecksum);
}
}
s = copy_file_cb(db_->GetName(), src_fname, 0, kTableFile, checksum_name,
checksum_value);
}
}
if (s.ok() && !current_fname.empty() && !manifest_fname.empty()) {
create_file_cb(current_fname, manifest_fname.substr(1) + "\n",
kCurrentFile);
}
ROCKS_LOG_INFO(db_options.info_log, "Number of log files %" ROCKSDB_PRIszt,
live_wal_files.size());
// Link WAL files. Copy exact size of last one because it is the only one
// that has changes after the last flush.
for (size_t i = 0; s.ok() && i < wal_size; ++i) {
if ((live_wal_files[i]->Type() == kAliveLogFile) &&
(!flush_memtable ||
live_wal_files[i]->StartSequence() >= *sequence_number ||
live_wal_files[i]->LogNumber() >= min_log_num)) {
if (i + 1 == wal_size) {
s = copy_file_cb(db_options.wal_dir, live_wal_files[i]->PathName(),
live_wal_files[i]->SizeFileBytes(), kWalFile,
kUnknownFileChecksumFuncName, kUnknownFileChecksum);
break;
}
if (same_fs) {
// we only care about live log files
s = link_file_cb(db_options.wal_dir, live_wal_files[i]->PathName(),
kWalFile);
if (s.IsNotSupported()) {
same_fs = false;
s = Status::OK();
}
}
if (!same_fs) {
s = copy_file_cb(db_options.wal_dir, live_wal_files[i]->PathName(), 0,
kWalFile, kUnknownFileChecksumFuncName,
kUnknownFileChecksum);
}
}
}
return s;
}
// Exports all live SST files of a specified Column Family onto export_dir,
// returning SST files information in metadata.
Status CheckpointImpl::ExportColumnFamily(
ColumnFamilyHandle* handle, const std::string& export_dir,
ExportImportFilesMetaData** metadata) {
auto cfh = static_cast_with_check<ColumnFamilyHandleImpl>(handle);
const auto cf_name = cfh->GetName();
const auto db_options = db_->GetDBOptions();
assert(metadata != nullptr);
assert(*metadata == nullptr);
auto s = db_->GetEnv()->FileExists(export_dir);
if (s.ok()) {
return Status::InvalidArgument("Specified export_dir exists");
} else if (!s.IsNotFound()) {
assert(s.IsIOError());
return s;
}
const auto final_nonslash_idx = export_dir.find_last_not_of('/');
if (final_nonslash_idx == std::string::npos) {
return Status::InvalidArgument("Specified export_dir invalid");
}
ROCKS_LOG_INFO(db_options.info_log,
"[%s] export column family onto export directory %s",
cf_name.c_str(), export_dir.c_str());
// Create a temporary export directory.
const auto tmp_export_dir =
export_dir.substr(0, final_nonslash_idx + 1) + ".tmp";
s = db_->GetEnv()->CreateDir(tmp_export_dir);
if (s.ok()) {
s = db_->Flush(ROCKSDB_NAMESPACE::FlushOptions(), handle);
}
ColumnFamilyMetaData db_metadata;
if (s.ok()) {
// Export live sst files with file deletions disabled.
s = db_->DisableFileDeletions();
if (s.ok()) {
db_->GetColumnFamilyMetaData(handle, &db_metadata);
s = ExportFilesInMetaData(
db_options, db_metadata,
[&](const std::string& src_dirname, const std::string& fname) {
ROCKS_LOG_INFO(db_options.info_log, "[%s] HardLinking %s",
cf_name.c_str(), fname.c_str());
return db_->GetEnv()->LinkFile(src_dirname + fname,
tmp_export_dir + fname);
} /*link_file_cb*/,
[&](const std::string& src_dirname, const std::string& fname) {
ROCKS_LOG_INFO(db_options.info_log, "[%s] Copying %s",
cf_name.c_str(), fname.c_str());
return CopyFile(db_->GetFileSystem(), src_dirname + fname,
tmp_export_dir + fname, 0, db_options.use_fsync);
} /*copy_file_cb*/);
const auto enable_status = db_->EnableFileDeletions(false /*force*/);
if (s.ok()) {
s = enable_status;
}
}
}
auto moved_to_user_specified_dir = false;
if (s.ok()) {
// Move temporary export directory to the actual export directory.
s = db_->GetEnv()->RenameFile(tmp_export_dir, export_dir);
}
if (s.ok()) {
// Fsync export directory.
moved_to_user_specified_dir = true;
std::unique_ptr<Directory> dir_ptr;
s = db_->GetEnv()->NewDirectory(export_dir, &dir_ptr);
if (s.ok()) {
assert(dir_ptr != nullptr);
s = dir_ptr->Fsync();
}
}
if (s.ok()) {
// Export of files succeeded. Fill in the metadata information.
auto result_metadata = new ExportImportFilesMetaData();
result_metadata->db_comparator_name = handle->GetComparator()->Name();
for (const auto& level_metadata : db_metadata.levels) {
for (const auto& file_metadata : level_metadata.files) {
LiveFileMetaData live_file_metadata;
live_file_metadata.size = file_metadata.size;
live_file_metadata.name = std::move(file_metadata.name);
live_file_metadata.file_number = file_metadata.file_number;
live_file_metadata.db_path = export_dir;
live_file_metadata.smallest_seqno = file_metadata.smallest_seqno;
live_file_metadata.largest_seqno = file_metadata.largest_seqno;
live_file_metadata.smallestkey = std::move(file_metadata.smallestkey);
live_file_metadata.largestkey = std::move(file_metadata.largestkey);
live_file_metadata.oldest_blob_file_number =
file_metadata.oldest_blob_file_number;
live_file_metadata.level = level_metadata.level;
result_metadata->files.push_back(live_file_metadata);
}
*metadata = result_metadata;
}
ROCKS_LOG_INFO(db_options.info_log, "[%s] Export succeeded.",
cf_name.c_str());
} else {
// Failure: Clean up all the files/directories created.
ROCKS_LOG_INFO(db_options.info_log, "[%s] Export failed. %s",
cf_name.c_str(), s.ToString().c_str());
std::vector<std::string> subchildren;
const auto cleanup_dir =
moved_to_user_specified_dir ? export_dir : tmp_export_dir;
db_->GetEnv()->GetChildren(cleanup_dir, &subchildren);
for (const auto& subchild : subchildren) {
const auto subchild_path = cleanup_dir + "/" + subchild;
const auto status = db_->GetEnv()->DeleteFile(subchild_path);
if (!status.ok()) {
ROCKS_LOG_WARN(db_options.info_log, "Failed to cleanup file %s: %s",
subchild_path.c_str(), status.ToString().c_str());
}
}
const auto status = db_->GetEnv()->DeleteDir(cleanup_dir);
if (!status.ok()) {
ROCKS_LOG_WARN(db_options.info_log, "Failed to cleanup dir %s: %s",
cleanup_dir.c_str(), status.ToString().c_str());
}
}
return s;
}
Status CheckpointImpl::ExportFilesInMetaData(
const DBOptions& db_options, const ColumnFamilyMetaData& metadata,
std::function<Status(const std::string& src_dirname,
const std::string& src_fname)>
link_file_cb,
std::function<Status(const std::string& src_dirname,
const std::string& src_fname)>
copy_file_cb) {
Status s;
auto hardlink_file = true;
// Copy/hard link files in metadata.
size_t num_files = 0;
for (const auto& level_metadata : metadata.levels) {
for (const auto& file_metadata : level_metadata.files) {
uint64_t number;
FileType type;
const auto ok = ParseFileName(file_metadata.name, &number, &type);
if (!ok) {
s = Status::Corruption("Could not parse file name");
break;
}
// We should only get sst files here.
assert(type == kTableFile);
assert(file_metadata.size > 0 && file_metadata.name[0] == '/');
const auto src_fname = file_metadata.name;
++num_files;
if (hardlink_file) {
s = link_file_cb(db_->GetName(), src_fname);
if (num_files == 1 && s.IsNotSupported()) {
// Fallback to copy if link failed due to cross-device directories.
hardlink_file = false;
s = Status::OK();
}
}
if (!hardlink_file) {
s = copy_file_cb(db_->GetName(), src_fname);
}
if (!s.ok()) {
break;
}
}
}
ROCKS_LOG_INFO(db_options.info_log, "Number of table files %" ROCKSDB_PRIszt,
num_files);
return s;
}
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE