rocksdb/db/version_edit.cc
Vijay Nadimpalli 979fbdc696 Persistent globally unique DB ID in manifest (#5725)
Summary:
Each DB has a globally unique ID. A DB can be physically copied around, or backed-up and restored, and the users should be identify the same DB. This unique ID right now is stored as plain text in file IDENTITY under the DB directory. This approach introduces at least two problems: (1) the file is not checksumed; (2) the source of truth of a DB is the manifest file, which can be copied separately from IDENTITY file, causing the DB ID to be wrong.
The goal of this PR is solve this problem by moving the  DB ID to manifest. To begin with we will write to both identity file and manifest. Write to Manifest is controlled via the flag write_dbid_to_manifest in Options and default is false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5725

Test Plan: Added unit tests.

Differential Revision: D16963840

Pulled By: vjnadimpalli

fbshipit-source-id: 8a86a4c8c82c716003c40fd6b9d2d758030d92e9
2019-09-03 08:52:24 -07:00

709 lines
21 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) 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.
#include "db/version_edit.h"
#include "db/version_set.h"
#include "logging/event_logger.h"
#include "rocksdb/slice.h"
#include "test_util/sync_point.h"
#include "util/coding.h"
#include "util/string_util.h"
namespace rocksdb {
// Mask for an identified tag from the future which can be safely ignored.
const uint32_t kTagSafeIgnoreMask = 1 << 13;
// Tag numbers for serialized VersionEdit. These numbers are written to
// disk and should not be changed. The number should be forward compatible so
// users can down-grade RocksDB safely. A future Tag is ignored by doing '&'
// between Tag and kTagSafeIgnoreMask field.
enum Tag : uint32_t {
kComparator = 1,
kLogNumber = 2,
kNextFileNumber = 3,
kLastSequence = 4,
kCompactPointer = 5,
kDeletedFile = 6,
kNewFile = 7,
// 8 was used for large value refs
kPrevLogNumber = 9,
kMinLogNumberToKeep = 10,
// Ignore-able field
kDbId = kTagSafeIgnoreMask + 1,
// these are new formats divergent from open source leveldb
kNewFile2 = 100,
kNewFile3 = 102,
kNewFile4 = 103, // 4th (the latest) format version of adding files
kColumnFamily = 200, // specify column family for version edit
kColumnFamilyAdd = 201,
kColumnFamilyDrop = 202,
kMaxColumnFamily = 203,
kInAtomicGroup = 300,
};
enum CustomTag : uint32_t {
kTerminate = 1, // The end of customized fields
kNeedCompaction = 2,
// Since Manifest is not entirely currently forward-compatible, and the only
// forward-compatible part is the CutsomtTag of kNewFile, we currently encode
// kMinLogNumberToKeep as part of a CustomTag as a hack. This should be
// removed when manifest becomes forward-comptabile.
kMinLogNumberToKeepHack = 3,
kPathId = 65,
};
// If this bit for the custom tag is set, opening DB should fail if
// we don't know this field.
uint32_t kCustomTagNonSafeIgnoreMask = 1 << 6;
uint64_t PackFileNumberAndPathId(uint64_t number, uint64_t path_id) {
assert(number <= kFileNumberMask);
return number | (path_id * (kFileNumberMask + 1));
}
void VersionEdit::Clear() {
db_id_.clear();
comparator_.clear();
max_level_ = 0;
log_number_ = 0;
prev_log_number_ = 0;
last_sequence_ = 0;
next_file_number_ = 0;
max_column_family_ = 0;
min_log_number_to_keep_ = 0;
has_db_id_ = false;
has_comparator_ = false;
has_log_number_ = false;
has_prev_log_number_ = false;
has_next_file_number_ = false;
has_last_sequence_ = false;
has_max_column_family_ = false;
has_min_log_number_to_keep_ = false;
deleted_files_.clear();
new_files_.clear();
column_family_ = 0;
is_column_family_add_ = 0;
is_column_family_drop_ = 0;
column_family_name_.clear();
is_in_atomic_group_ = false;
remaining_entries_ = 0;
}
bool VersionEdit::EncodeTo(std::string* dst) const {
if (has_db_id_) {
PutVarint32(dst, kDbId);
PutLengthPrefixedSlice(dst, db_id_);
}
if (has_comparator_) {
PutVarint32(dst, kComparator);
PutLengthPrefixedSlice(dst, comparator_);
}
if (has_log_number_) {
PutVarint32Varint64(dst, kLogNumber, log_number_);
}
if (has_prev_log_number_) {
PutVarint32Varint64(dst, kPrevLogNumber, prev_log_number_);
}
if (has_next_file_number_) {
PutVarint32Varint64(dst, kNextFileNumber, next_file_number_);
}
if (has_last_sequence_) {
PutVarint32Varint64(dst, kLastSequence, last_sequence_);
}
if (has_max_column_family_) {
PutVarint32Varint32(dst, kMaxColumnFamily, max_column_family_);
}
for (const auto& deleted : deleted_files_) {
PutVarint32Varint32Varint64(dst, kDeletedFile, deleted.first /* level */,
deleted.second /* file number */);
}
bool min_log_num_written = false;
for (size_t i = 0; i < new_files_.size(); i++) {
const FileMetaData& f = new_files_[i].second;
if (!f.smallest.Valid() || !f.largest.Valid()) {
return false;
}
bool has_customized_fields = false;
if (f.marked_for_compaction || has_min_log_number_to_keep_) {
PutVarint32(dst, kNewFile4);
has_customized_fields = true;
} else if (f.fd.GetPathId() == 0) {
// Use older format to make sure user can roll back the build if they
// don't config multiple DB paths.
PutVarint32(dst, kNewFile2);
} else {
PutVarint32(dst, kNewFile3);
}
PutVarint32Varint64(dst, new_files_[i].first /* level */, f.fd.GetNumber());
if (f.fd.GetPathId() != 0 && !has_customized_fields) {
// kNewFile3
PutVarint32(dst, f.fd.GetPathId());
}
PutVarint64(dst, f.fd.GetFileSize());
PutLengthPrefixedSlice(dst, f.smallest.Encode());
PutLengthPrefixedSlice(dst, f.largest.Encode());
PutVarint64Varint64(dst, f.fd.smallest_seqno, f.fd.largest_seqno);
if (has_customized_fields) {
// Customized fields' format:
// +-----------------------------+
// | 1st field's tag (varint32) |
// +-----------------------------+
// | 1st field's size (varint32) |
// +-----------------------------+
// | bytes for 1st field |
// | (based on size decoded) |
// +-----------------------------+
// | |
// | ...... |
// | |
// +-----------------------------+
// | last field's size (varint32)|
// +-----------------------------+
// | bytes for last field |
// | (based on size decoded) |
// +-----------------------------+
// | terminating tag (varint32) |
// +-----------------------------+
//
// Customized encoding for fields:
// tag kPathId: 1 byte as path_id
// tag kNeedCompaction:
// now only can take one char value 1 indicating need-compaction
//
if (f.fd.GetPathId() != 0) {
PutVarint32(dst, CustomTag::kPathId);
char p = static_cast<char>(f.fd.GetPathId());
PutLengthPrefixedSlice(dst, Slice(&p, 1));
}
if (f.marked_for_compaction) {
PutVarint32(dst, CustomTag::kNeedCompaction);
char p = static_cast<char>(1);
PutLengthPrefixedSlice(dst, Slice(&p, 1));
}
if (has_min_log_number_to_keep_ && !min_log_num_written) {
PutVarint32(dst, CustomTag::kMinLogNumberToKeepHack);
std::string varint_log_number;
PutFixed64(&varint_log_number, min_log_number_to_keep_);
PutLengthPrefixedSlice(dst, Slice(varint_log_number));
min_log_num_written = true;
}
TEST_SYNC_POINT_CALLBACK("VersionEdit::EncodeTo:NewFile4:CustomizeFields",
dst);
PutVarint32(dst, CustomTag::kTerminate);
}
}
// 0 is default and does not need to be explicitly written
if (column_family_ != 0) {
PutVarint32Varint32(dst, kColumnFamily, column_family_);
}
if (is_column_family_add_) {
PutVarint32(dst, kColumnFamilyAdd);
PutLengthPrefixedSlice(dst, Slice(column_family_name_));
}
if (is_column_family_drop_) {
PutVarint32(dst, kColumnFamilyDrop);
}
if (is_in_atomic_group_) {
PutVarint32(dst, kInAtomicGroup);
PutVarint32(dst, remaining_entries_);
}
return true;
}
static bool GetInternalKey(Slice* input, InternalKey* dst) {
Slice str;
if (GetLengthPrefixedSlice(input, &str)) {
dst->DecodeFrom(str);
return dst->Valid();
} else {
return false;
}
}
bool VersionEdit::GetLevel(Slice* input, int* level, const char** /*msg*/) {
uint32_t v;
if (GetVarint32(input, &v)) {
*level = v;
if (max_level_ < *level) {
max_level_ = *level;
}
return true;
} else {
return false;
}
}
const char* VersionEdit::DecodeNewFile4From(Slice* input) {
const char* msg = nullptr;
int level;
FileMetaData f;
uint64_t number;
uint32_t path_id = 0;
uint64_t file_size;
SequenceNumber smallest_seqno;
SequenceNumber largest_seqno;
// Since this is the only forward-compatible part of the code, we hack new
// extension into this record. When we do, we set this boolean to distinguish
// the record from the normal NewFile records.
if (GetLevel(input, &level, &msg) && GetVarint64(input, &number) &&
GetVarint64(input, &file_size) && GetInternalKey(input, &f.smallest) &&
GetInternalKey(input, &f.largest) &&
GetVarint64(input, &smallest_seqno) &&
GetVarint64(input, &largest_seqno)) {
// See comments in VersionEdit::EncodeTo() for format of customized fields
while (true) {
uint32_t custom_tag;
Slice field;
if (!GetVarint32(input, &custom_tag)) {
return "new-file4 custom field";
}
if (custom_tag == kTerminate) {
break;
}
if (!GetLengthPrefixedSlice(input, &field)) {
return "new-file4 custom field length prefixed slice error";
}
switch (custom_tag) {
case kPathId:
if (field.size() != 1) {
return "path_id field wrong size";
}
path_id = field[0];
if (path_id > 3) {
return "path_id wrong vaue";
}
break;
case kNeedCompaction:
if (field.size() != 1) {
return "need_compaction field wrong size";
}
f.marked_for_compaction = (field[0] == 1);
break;
case kMinLogNumberToKeepHack:
// This is a hack to encode kMinLogNumberToKeep in a
// forward-compatible fashion.
if (!GetFixed64(&field, &min_log_number_to_keep_)) {
return "deleted log number malformatted";
}
has_min_log_number_to_keep_ = true;
break;
default:
if ((custom_tag & kCustomTagNonSafeIgnoreMask) != 0) {
// Should not proceed if cannot understand it
return "new-file4 custom field not supported";
}
break;
}
}
} else {
return "new-file4 entry";
}
f.fd =
FileDescriptor(number, path_id, file_size, smallest_seqno, largest_seqno);
new_files_.push_back(std::make_pair(level, f));
return nullptr;
}
Status VersionEdit::DecodeFrom(const Slice& src) {
Clear();
Slice input = src;
const char* msg = nullptr;
uint32_t tag;
// Temporary storage for parsing
int level;
FileMetaData f;
Slice str;
InternalKey key;
while (msg == nullptr && GetVarint32(&input, &tag)) {
switch (tag) {
case kDbId:
if (GetLengthPrefixedSlice(&input, &str)) {
db_id_ = str.ToString();
has_db_id_ = true;
} else {
msg = "db id";
}
break;
case kComparator:
if (GetLengthPrefixedSlice(&input, &str)) {
comparator_ = str.ToString();
has_comparator_ = true;
} else {
msg = "comparator name";
}
break;
case kLogNumber:
if (GetVarint64(&input, &log_number_)) {
has_log_number_ = true;
} else {
msg = "log number";
}
break;
case kPrevLogNumber:
if (GetVarint64(&input, &prev_log_number_)) {
has_prev_log_number_ = true;
} else {
msg = "previous log number";
}
break;
case kNextFileNumber:
if (GetVarint64(&input, &next_file_number_)) {
has_next_file_number_ = true;
} else {
msg = "next file number";
}
break;
case kLastSequence:
if (GetVarint64(&input, &last_sequence_)) {
has_last_sequence_ = true;
} else {
msg = "last sequence number";
}
break;
case kMaxColumnFamily:
if (GetVarint32(&input, &max_column_family_)) {
has_max_column_family_ = true;
} else {
msg = "max column family";
}
break;
case kMinLogNumberToKeep:
if (GetVarint64(&input, &min_log_number_to_keep_)) {
has_min_log_number_to_keep_ = true;
} else {
msg = "min log number to kee";
}
break;
case kCompactPointer:
if (GetLevel(&input, &level, &msg) &&
GetInternalKey(&input, &key)) {
// we don't use compact pointers anymore,
// but we should not fail if they are still
// in manifest
} else {
if (!msg) {
msg = "compaction pointer";
}
}
break;
case kDeletedFile: {
uint64_t number;
if (GetLevel(&input, &level, &msg) && GetVarint64(&input, &number)) {
deleted_files_.insert(std::make_pair(level, number));
} else {
if (!msg) {
msg = "deleted file";
}
}
break;
}
case kNewFile: {
uint64_t number;
uint64_t file_size;
if (GetLevel(&input, &level, &msg) && GetVarint64(&input, &number) &&
GetVarint64(&input, &file_size) &&
GetInternalKey(&input, &f.smallest) &&
GetInternalKey(&input, &f.largest)) {
f.fd = FileDescriptor(number, 0, file_size);
new_files_.push_back(std::make_pair(level, f));
} else {
if (!msg) {
msg = "new-file entry";
}
}
break;
}
case kNewFile2: {
uint64_t number;
uint64_t file_size;
SequenceNumber smallest_seqno;
SequenceNumber largest_seqno;
if (GetLevel(&input, &level, &msg) && GetVarint64(&input, &number) &&
GetVarint64(&input, &file_size) &&
GetInternalKey(&input, &f.smallest) &&
GetInternalKey(&input, &f.largest) &&
GetVarint64(&input, &smallest_seqno) &&
GetVarint64(&input, &largest_seqno)) {
f.fd = FileDescriptor(number, 0, file_size, smallest_seqno,
largest_seqno);
new_files_.push_back(std::make_pair(level, f));
} else {
if (!msg) {
msg = "new-file2 entry";
}
}
break;
}
case kNewFile3: {
uint64_t number;
uint32_t path_id;
uint64_t file_size;
SequenceNumber smallest_seqno;
SequenceNumber largest_seqno;
if (GetLevel(&input, &level, &msg) && GetVarint64(&input, &number) &&
GetVarint32(&input, &path_id) && GetVarint64(&input, &file_size) &&
GetInternalKey(&input, &f.smallest) &&
GetInternalKey(&input, &f.largest) &&
GetVarint64(&input, &smallest_seqno) &&
GetVarint64(&input, &largest_seqno)) {
f.fd = FileDescriptor(number, path_id, file_size, smallest_seqno,
largest_seqno);
new_files_.push_back(std::make_pair(level, f));
} else {
if (!msg) {
msg = "new-file3 entry";
}
}
break;
}
case kNewFile4: {
msg = DecodeNewFile4From(&input);
break;
}
case kColumnFamily:
if (!GetVarint32(&input, &column_family_)) {
if (!msg) {
msg = "set column family id";
}
}
break;
case kColumnFamilyAdd:
if (GetLengthPrefixedSlice(&input, &str)) {
is_column_family_add_ = true;
column_family_name_ = str.ToString();
} else {
if (!msg) {
msg = "column family add";
}
}
break;
case kColumnFamilyDrop:
is_column_family_drop_ = true;
break;
case kInAtomicGroup:
is_in_atomic_group_ = true;
if (!GetVarint32(&input, &remaining_entries_)) {
if (!msg) {
msg = "remaining entries";
}
}
break;
default:
if (tag & kTagSafeIgnoreMask) {
// Tag from future which can be safely ignored.
// The next field must be the length of the entry.
uint32_t field_len;
if (!GetVarint32(&input, &field_len) ||
static_cast<size_t>(field_len) > input.size()) {
if (!msg) {
msg = "safely ignoreable tag length error";
}
} else {
input.remove_prefix(static_cast<size_t>(field_len));
}
} else {
msg = "unknown tag";
}
break;
}
}
if (msg == nullptr && !input.empty()) {
msg = "invalid tag";
}
Status result;
if (msg != nullptr) {
result = Status::Corruption("VersionEdit", msg);
}
return result;
}
std::string VersionEdit::DebugString(bool hex_key) const {
std::string r;
r.append("VersionEdit {");
if (has_db_id_) {
r.append("\n DB ID: ");
r.append(db_id_);
}
if (has_comparator_) {
r.append("\n Comparator: ");
r.append(comparator_);
}
if (has_log_number_) {
r.append("\n LogNumber: ");
AppendNumberTo(&r, log_number_);
}
if (has_prev_log_number_) {
r.append("\n PrevLogNumber: ");
AppendNumberTo(&r, prev_log_number_);
}
if (has_next_file_number_) {
r.append("\n NextFileNumber: ");
AppendNumberTo(&r, next_file_number_);
}
if (has_min_log_number_to_keep_) {
r.append("\n MinLogNumberToKeep: ");
AppendNumberTo(&r, min_log_number_to_keep_);
}
if (has_last_sequence_) {
r.append("\n LastSeq: ");
AppendNumberTo(&r, last_sequence_);
}
for (DeletedFileSet::const_iterator iter = deleted_files_.begin();
iter != deleted_files_.end();
++iter) {
r.append("\n DeleteFile: ");
AppendNumberTo(&r, iter->first);
r.append(" ");
AppendNumberTo(&r, iter->second);
}
for (size_t i = 0; i < new_files_.size(); i++) {
const FileMetaData& f = new_files_[i].second;
r.append("\n AddFile: ");
AppendNumberTo(&r, new_files_[i].first);
r.append(" ");
AppendNumberTo(&r, f.fd.GetNumber());
r.append(" ");
AppendNumberTo(&r, f.fd.GetFileSize());
r.append(" ");
r.append(f.smallest.DebugString(hex_key));
r.append(" .. ");
r.append(f.largest.DebugString(hex_key));
}
r.append("\n ColumnFamily: ");
AppendNumberTo(&r, column_family_);
if (is_column_family_add_) {
r.append("\n ColumnFamilyAdd: ");
r.append(column_family_name_);
}
if (is_column_family_drop_) {
r.append("\n ColumnFamilyDrop");
}
if (has_max_column_family_) {
r.append("\n MaxColumnFamily: ");
AppendNumberTo(&r, max_column_family_);
}
if (is_in_atomic_group_) {
r.append("\n AtomicGroup: ");
AppendNumberTo(&r, remaining_entries_);
r.append(" entries remains");
}
r.append("\n}\n");
return r;
}
std::string VersionEdit::DebugJSON(int edit_num, bool hex_key) const {
JSONWriter jw;
jw << "EditNumber" << edit_num;
if (has_db_id_) {
jw << "DB ID" << db_id_;
}
if (has_comparator_) {
jw << "Comparator" << comparator_;
}
if (has_log_number_) {
jw << "LogNumber" << log_number_;
}
if (has_prev_log_number_) {
jw << "PrevLogNumber" << prev_log_number_;
}
if (has_next_file_number_) {
jw << "NextFileNumber" << next_file_number_;
}
if (has_last_sequence_) {
jw << "LastSeq" << last_sequence_;
}
if (!deleted_files_.empty()) {
jw << "DeletedFiles";
jw.StartArray();
for (DeletedFileSet::const_iterator iter = deleted_files_.begin();
iter != deleted_files_.end();
++iter) {
jw.StartArrayedObject();
jw << "Level" << iter->first;
jw << "FileNumber" << iter->second;
jw.EndArrayedObject();
}
jw.EndArray();
}
if (!new_files_.empty()) {
jw << "AddedFiles";
jw.StartArray();
for (size_t i = 0; i < new_files_.size(); i++) {
jw.StartArrayedObject();
jw << "Level" << new_files_[i].first;
const FileMetaData& f = new_files_[i].second;
jw << "FileNumber" << f.fd.GetNumber();
jw << "FileSize" << f.fd.GetFileSize();
jw << "SmallestIKey" << f.smallest.DebugString(hex_key);
jw << "LargestIKey" << f.largest.DebugString(hex_key);
jw.EndArrayedObject();
}
jw.EndArray();
}
jw << "ColumnFamily" << column_family_;
if (is_column_family_add_) {
jw << "ColumnFamilyAdd" << column_family_name_;
}
if (is_column_family_drop_) {
jw << "ColumnFamilyDrop" << column_family_name_;
}
if (has_max_column_family_) {
jw << "MaxColumnFamily" << max_column_family_;
}
if (has_min_log_number_to_keep_) {
jw << "MinLogNumberToKeep" << min_log_number_to_keep_;
}
if (is_in_atomic_group_) {
jw << "AtomicGroup" << remaining_entries_;
}
jw.EndObject();
return jw.Get();
}
} // namespace rocksdb