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arangodb/arangod/Wal/LogfileManager.cpp

586 lines
18 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief Write-ahead log logfile manager
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2013 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "LogfileManager.h"
#include "BasicsC/json.h"
#include "BasicsC/logging.h"
#include "Basics/Exceptions.h"
#include "Basics/FileUtils.h"
#include "Basics/JsonHelper.h"
#include "Basics/MutexLocker.h"
#include "Basics/ReadLocker.h"
#include "Basics/StringUtils.h"
#include "Basics/WriteLocker.h"
#include "Wal/AllocatorThread.h"
#include "Wal/CollectorThread.h"
#include "Wal/Configuration.h"
using namespace triagens::wal;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief create the logfile manager
////////////////////////////////////////////////////////////////////////////////
LogfileManager::LogfileManager (Configuration* configuration)
: _configuration(configuration),
_tickLock(),
_tick(0),
_allocatorThread(nullptr),
_collectorThread(nullptr),
_logfileIdLock(),
_logfileId(0),
_lastCollectedId(0),
_logfilesLock(),
_logfiles(),
_directory(configuration->directory()) {
int res = regcomp(&_regex, "^logfile-([0-9][0-9]*)\\.db$", REG_EXTENDED);
if (res != 0) {
THROW_INTERNAL_ERROR("could not compile regex");
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destroy the logfile manager
////////////////////////////////////////////////////////////////////////////////
LogfileManager::~LogfileManager () {
shutdown();
regfree(&_regex);
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief startup the logfile manager
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::startup () {
int res = inventory();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not create wal logfile inventory: %s", TRI_errno_string(res));
return res;
}
std::string const shutdownFile = shutdownFilename();
bool const shutdownFileExists = basics::FileUtils::exists(shutdownFile);
if (shutdownFileExists) {
res = readShutdownInfo();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not open shutdown file '%s': %s", shutdownFile.c_str(), TRI_errno_string(res));
return res;
}
}
res = openLogfiles();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not open wal logfiles: %s", TRI_errno_string(res));
return res;
}
res = reserveSpace();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not reserve wal space: %s", TRI_errno_string(res));
return res;
}
res = startAllocatorThread();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not start wal allocator thread: %s", TRI_errno_string(res));
return res;
}
res = startCollectorThread();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not start wal collector thread: %s", TRI_errno_string(res));
return res;
}
if (shutdownFileExists) {
// delete the shutdown file if it existed
if (! basics::FileUtils::remove(shutdownFile, &res)) {
LOG_ERROR("could not remove shutdown file '%s': %s", shutdownFile.c_str(), TRI_errno_string(res));
return res;
}
}
LOG_INFO("wal logfile manager started successfully");
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief shuts down and closes all open logfiles
////////////////////////////////////////////////////////////////////////////////
void LogfileManager::shutdown () {
// stop threads
stopCollectorThread();
stopAllocatorThread();
// close all open logfiles
WRITE_LOCKER(_logfilesLock);
for (auto it = _logfiles.begin(); it != _logfiles.end(); ++it) {
Logfile* logfile = (*it).second;
if (logfile != nullptr) {
delete logfile;
}
}
_logfiles.clear();
int res = writeShutdownInfo();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("could not write wal shutdown info: %s", TRI_errno_string(res));
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief reserve space in a log file
////////////////////////////////////////////////////////////////////////////////
LogEntry LogfileManager::reserve (size_t size) {
LogEntry::TickType const tick = nextTick();
LogEntry entry = LogEntry(0, size, tick);
return entry;
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief increases the tick value and returns it
////////////////////////////////////////////////////////////////////////////////
LogEntry::TickType LogfileManager::nextTick () {
WRITE_LOCKER(_tickLock);
return ++_tick;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the last assigned tick
////////////////////////////////////////////////////////////////////////////////
LogEntry::TickType LogfileManager::lastTick () {
READ_LOCKER(_tickLock);
return _tick;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the id of the last fully collected logfile
/// returns 0 if no logfile was yet collected or no information about the
/// collection is present
////////////////////////////////////////////////////////////////////////////////
Logfile::IdType LogfileManager::lastCollected () {
MUTEX_LOCKER(_logfileIdLock);
return _lastCollectedId;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief reads the shutdown information
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::readShutdownInfo () {
std::string const filename = shutdownFilename();
TRI_json_t* json = TRI_JsonFile(TRI_UNKNOWN_MEM_ZONE, filename.c_str(), nullptr);
if (json == nullptr) {
return TRI_ERROR_INTERNAL;
}
// read last assigned tick (may be 0)
uint64_t const lastTick = basics::JsonHelper::stringUInt64(json, "lastTick");
{
WRITE_LOCKER(_tickLock);
_tick = static_cast<LogEntry::TickType>(lastTick);
}
// read if of last collected logfile (maybe 0)
uint64_t const lastCollected = basics::JsonHelper::stringUInt64(json, "lastCollected");
{
MUTEX_LOCKER(_logfileIdLock);
_lastCollectedId = static_cast<Logfile::IdType>(lastCollected);
}
TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, json);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief writes the shutdown information
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::writeShutdownInfo () {
std::string const filename = shutdownFilename();
std::string content;
content.append("{\"lastTick\":\"");
content.append(basics::StringUtils::itoa(lastTick()));
content.append("\",\"lastCollected\":\"");
content.append(basics::StringUtils::itoa(lastCollected()));
content.append("\"}");
// TODO: spit() doesn't return success/failure. FIXME!
basics::FileUtils::spit(filename, content);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief start the allocator thread
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::startAllocatorThread () {
_allocatorThread = new AllocatorThread(this);
if (_allocatorThread == nullptr) {
return TRI_ERROR_INTERNAL;
}
if (! _allocatorThread->init() ||
! _allocatorThread->start()) {
return TRI_ERROR_INTERNAL;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief stop the allocator thread
////////////////////////////////////////////////////////////////////////////////
void LogfileManager::stopAllocatorThread () {
if (_allocatorThread != nullptr) {
LOG_TRACE("stopping wal allocator thread");
_allocatorThread->stop();
_allocatorThread->shutdown();
delete _allocatorThread;
_allocatorThread = 0;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief start the collector thread
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::startCollectorThread () {
_collectorThread = new CollectorThread(this);
if (_collectorThread == nullptr) {
return TRI_ERROR_INTERNAL;
}
if (! _collectorThread->init() ||
! _collectorThread->start()) {
return TRI_ERROR_INTERNAL;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief stop the collector thread
////////////////////////////////////////////////////////////////////////////////
void LogfileManager::stopCollectorThread () {
if (_collectorThread != nullptr) {
LOG_TRACE("stopping wal collector thread");
_collectorThread->stop();
_collectorThread->shutdown();
delete _collectorThread;
_collectorThread = 0;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief check which logfiles are present in the log directory
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::inventory () {
int res = ensureDirectory();
if (res != TRI_ERROR_NO_ERROR) {
return res;
}
LOG_TRACE("scanning wal directory: '%s'", _directory.c_str());
std::vector<std::string> files = basics::FileUtils::listFiles(_directory);
for (auto it = files.begin(); it != files.end(); ++it) {
regmatch_t matches[2];
std::string const file = (*it);
char const* s = file.c_str();
if (regexec(&_regex, s, sizeof(matches) / sizeof(matches[1]), matches, 0) == 0) {
Logfile::IdType const id = basics::StringUtils::uint64(s + matches[1].rm_so, matches[1].rm_eo - matches[1].rm_so);
if (id == 0) {
LOG_WARNING("encountered invalid id for logfile '%s'. ids must be > 0", file.c_str());
}
else {
WRITE_LOCKER(_logfilesLock);
_logfiles.insert(make_pair(id, nullptr));
}
}
}
// now pick up the logfile with the highest id and use its id
READ_LOCKER(_logfilesLock);
if (! _logfiles.empty()) {
auto it = _logfiles.rbegin();
MUTEX_LOCKER(_logfileIdLock);
_logfileId = (*it).first;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief scan the logfiles in the log directory
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::openLogfiles () {
WRITE_LOCKER(_logfilesLock);
for (auto it = _logfiles.begin(); it != _logfiles.end(); ++it) {
Logfile::IdType const id = (*it).first;
std::string const filename = logfileName(id);
assert((*it).second == nullptr);
TRI_datafile_t* df = TRI_OpenDatafile(filename.c_str());
if (df == nullptr) {
int res = TRI_errno();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("unable to open logfile '%s': %s", filename.c_str(), TRI_errno_string(res));
return res;
}
}
(*it).second = new Logfile(df);
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief reserve space in the logfile directory
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::reserveSpace () {
while (shouldAllocate()) {
int res = allocateDatafile();
if (res != TRI_ERROR_NO_ERROR) {
LOG_ERROR("unable to allocate new datafile: %s", TRI_errno_string(res));
return res;
}
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not a new datafile must be allocated
////////////////////////////////////////////////////////////////////////////////
bool LogfileManager::shouldAllocate () {
uint64_t const maximum = _configuration->maximumSize();
uint64_t const reserve = _configuration->reserveSize();
uint64_t const allocated = allocatedSize();
uint64_t const free = freeSize();
if (allocated >= maximum) {
return false;
}
if (free >= reserve) {
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief total number of bytes allocated in datafiles
////////////////////////////////////////////////////////////////////////////////
uint64_t LogfileManager::allocatedSize () {
uint64_t allocated = 0;
READ_LOCKER(_logfilesLock);
for (auto it = _logfiles.begin(); it != _logfiles.end(); ++it) {
Logfile* logfile = (*it).second;
assert(logfile != nullptr);
allocated += logfile->allocatedSize();
}
return allocated;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief total number of free bytes in already allocated datafiles
////////////////////////////////////////////////////////////////////////////////
uint64_t LogfileManager::freeSize () {
uint64_t free = 0;
READ_LOCKER(_logfilesLock);
for (auto it = _logfiles.begin(); it != _logfiles.end(); ++it) {
Logfile* logfile = (*it).second;
assert(logfile != nullptr);
free += logfile->freeSize();
}
return free;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief allocate a new datafile
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::allocateDatafile () {
Logfile::IdType const id = nextId();
std::string const filename = logfileName(id);
TRI_datafile_t* df = TRI_CreateDatafile(filename.c_str(), id, static_cast<TRI_voc_size_t>(_configuration->filesize()));
if (df == nullptr) {
int res = TRI_errno();
LOG_ERROR("unable to create datafile: %s", TRI_errno_string(res));
return res;
}
WRITE_LOCKER(_logfilesLock);
_logfiles.insert(make_pair(id, new Logfile(df)));
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief run the recovery procedure
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::runRecovery () {
// TODO
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get an id for the next logfile
////////////////////////////////////////////////////////////////////////////////
Logfile::IdType LogfileManager::nextId () {
MUTEX_LOCKER(_logfileIdLock);
return ++_logfileId;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief ensure the wal logfiles directory is actually there
////////////////////////////////////////////////////////////////////////////////
int LogfileManager::ensureDirectory () {
if (! basics::FileUtils::isDirectory(_directory)) {
int res;
LOG_INFO("wal directory '%s' does not exist. creating it...", _directory.c_str());
if (! basics::FileUtils::createDirectory(_directory, &res)) {
LOG_ERROR("could not create wal directory: '%s': %s", _directory.c_str(), TRI_errno_string(res));
return res;
}
}
if (! basics::FileUtils::isDirectory(_directory)) {
LOG_ERROR("wal directory '%s' does not exist", _directory.c_str());
return TRI_ERROR_FILE_NOT_FOUND;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return an absolute filename for a logfile id
////////////////////////////////////////////////////////////////////////////////
std::string LogfileManager::logfileName (Logfile::IdType id) const {
return _directory + std::string("logfile-") + basics::StringUtils::itoa(id) + std::string(".db");
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the absolute name of the shutdown file
////////////////////////////////////////////////////////////////////////////////
std::string LogfileManager::shutdownFilename () const {
return _directory + std::string("SHUTDOWN");
}
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