rocksdb/util/status.cc
Yanqin Jin 9358178edc Support for single-primary, multi-secondary instances (#4899)
Summary:
This PR allows RocksDB to run in single-primary, multi-secondary process mode.
The writer is a regular RocksDB (e.g. an `DBImpl`) instance playing the role of a primary.
Multiple `DBImplSecondary` processes (secondaries) share the same set of SST files, MANIFEST, WAL files with the primary. Secondaries tail the MANIFEST of the primary and apply updates to their own in-memory state of the file system, e.g. `VersionStorageInfo`.

This PR has several components:
1. (Originally in #4745). Add a `PathNotFound` subcode to `IOError` to denote the failure when a secondary tries to open a file which has been deleted by the primary.

2. (Similar to #4602). Add `FragmentBufferedReader` to handle partially-read, trailing record at the end of a log from where future read can continue.

3. (Originally in #4710 and #4820). Add implementation of the secondary, i.e. `DBImplSecondary`.
3.1 Tail the primary's MANIFEST during recovery.
3.2 Tail the primary's MANIFEST during normal processing by calling `ReadAndApply`.
3.3 Tailing WAL will be in a future PR.

4. Add an example in 'examples/multi_processes_example.cc' to demonstrate the usage of secondary RocksDB instance in a multi-process setting. Instructions to run the example can be found at the beginning of the source code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4899

Differential Revision: D14510945

Pulled By: riversand963

fbshipit-source-id: 4ac1c5693e6012ad23f7b4b42d3c374fecbe8886
2019-03-26 16:45:31 -07:00

132 lines
3.9 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 "rocksdb/status.h"
#include <stdio.h>
#ifdef OS_WIN
#include <string.h>
#endif
#include <cstring>
#include "port/port.h"
namespace rocksdb {
const char* Status::CopyState(const char* state) {
#ifdef OS_WIN
const size_t cch = std::strlen(state) + 1; // +1 for the null terminator
char* result = new char[cch];
errno_t ret;
ret = strncpy_s(result, cch, state, cch - 1);
result[cch - 1] = '\0';
assert(ret == 0);
return result;
#else
const size_t cch = std::strlen(state) + 1; // +1 for the null terminator
return std::strncpy(new char[cch], state, cch);
#endif
}
static const char* msgs[static_cast<int>(Status::kMaxSubCode)] = {
"", // kNone
"Timeout Acquiring Mutex", // kMutexTimeout
"Timeout waiting to lock key", // kLockTimeout
"Failed to acquire lock due to max_num_locks limit", // kLockLimit
"No space left on device", // kNoSpace
"Deadlock", // kDeadlock
"Stale file handle", // kStaleFile
"Memory limit reached", // kMemoryLimit
"Space limit reached", // kSpaceLimit
"No such file or directory", // kPathNotFound
};
Status::Status(Code _code, SubCode _subcode, const Slice& msg,
const Slice& msg2)
: code_(_code), subcode_(_subcode), sev_(kNoError) {
assert(code_ != kOk);
assert(subcode_ != kMaxSubCode);
const size_t len1 = msg.size();
const size_t len2 = msg2.size();
const size_t size = len1 + (len2 ? (2 + len2) : 0);
char* const result = new char[size + 1]; // +1 for null terminator
memcpy(result, msg.data(), len1);
if (len2) {
result[len1] = ':';
result[len1 + 1] = ' ';
memcpy(result + len1 + 2, msg2.data(), len2);
}
result[size] = '\0'; // null terminator for C style string
state_ = result;
}
std::string Status::ToString() const {
char tmp[30];
const char* type;
switch (code_) {
case kOk:
return "OK";
case kNotFound:
type = "NotFound: ";
break;
case kCorruption:
type = "Corruption: ";
break;
case kNotSupported:
type = "Not implemented: ";
break;
case kInvalidArgument:
type = "Invalid argument: ";
break;
case kIOError:
type = "IO error: ";
break;
case kMergeInProgress:
type = "Merge in progress: ";
break;
case kIncomplete:
type = "Result incomplete: ";
break;
case kShutdownInProgress:
type = "Shutdown in progress: ";
break;
case kTimedOut:
type = "Operation timed out: ";
break;
case kAborted:
type = "Operation aborted: ";
break;
case kBusy:
type = "Resource busy: ";
break;
case kExpired:
type = "Operation expired: ";
break;
case kTryAgain:
type = "Operation failed. Try again.: ";
break;
default:
snprintf(tmp, sizeof(tmp), "Unknown code(%d): ",
static_cast<int>(code()));
type = tmp;
break;
}
std::string result(type);
if (subcode_ != kNone) {
uint32_t index = static_cast<int32_t>(subcode_);
assert(sizeof(msgs) > index);
result.append(msgs[index]);
}
if (state_ != nullptr) {
result.append(state_);
}
return result;
}
} // namespace rocksdb