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#include "ConfigReloader.h"
#include <Poco/Util/Application.h>
#include <Common/logger_useful.h>
#include <Common/setThreadName.h>
#include "ConfigProcessor.h"
#include <filesystem>
#include <Common/filesystemHelpers.h>
namespace fs = std::filesystem;
namespace DB
{
ConfigReloader::ConfigReloader(
std::string_view config_path_,
const std::vector<std::string>& extra_paths_,
const std::string & preprocessed_dir_,
zkutil::ZooKeeperNodeCache && zk_node_cache_,
const zkutil::EventPtr & zk_changed_event_,
Updater && updater_,
bool already_loaded)
: config_path(config_path_)
, extra_paths(extra_paths_)
, preprocessed_dir(preprocessed_dir_)
, zk_node_cache(std::move(zk_node_cache_))
, zk_changed_event(zk_changed_event_)
, updater(std::move(updater_))
{
if (!already_loaded)
reloadIfNewer(/* force = */ true, /* throw_on_error = */ true, /* fallback_to_preprocessed = */ true, /* initial_loading = */ true);
}
void ConfigReloader::start()
{
std::lock_guard lock(reload_mutex);
if (!thread.joinable())
{
quit = false;
thread = ThreadFromGlobalPool(&ConfigReloader::run, this);
}
}
void ConfigReloader::stop()
{
std::unique_lock lock(reload_mutex);
if (!thread.joinable())
return;
quit = true;
zk_changed_event->set();
auto temp_thread = std::move(thread);
lock.unlock();
temp_thread.join();
}
ConfigReloader::~ConfigReloader()
{
try
{
stop();
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
}
}
void ConfigReloader::run()
{
setThreadName("ConfigReloader");
while (true)
{
try
{
bool zk_changed = zk_changed_event->tryWait(std::chrono::milliseconds(reload_interval).count());
if (quit)
return;
reloadIfNewer(zk_changed, /* throw_on_error = */ false, /* fallback_to_preprocessed = */ false, /* initial_loading = */ false);
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
std::this_thread::sleep_for(reload_interval);
}
}
}
void ConfigReloader::reloadIfNewer(bool force, bool throw_on_error, bool fallback_to_preprocessed, bool initial_loading)
{
std::lock_guard lock(reload_mutex);
FilesChangesTracker new_files = getNewFileList();
if (force || need_reload_from_zk || new_files.isDifferOrNewerThan(files))
{
ConfigProcessor config_processor(config_path);
ConfigProcessor::LoadedConfig loaded_config;
LOG_DEBUG(log, "Loading config '{}'", config_path);
try
{
loaded_config = config_processor.loadConfig(/* allow_zk_includes = */ true);
if (loaded_config.has_zk_includes)
loaded_config = config_processor.loadConfigWithZooKeeperIncludes(
zk_node_cache, zk_changed_event, fallback_to_preprocessed);
}
catch (const Coordination::Exception & e)
{
if (Coordination::isHardwareError(e.code))
need_reload_from_zk = true;
if (throw_on_error)
throw;
tryLogCurrentException(log, "ZooKeeper error when loading config from '" + config_path + "'");
return;
}
catch (...)
{
if (throw_on_error)
throw;
tryLogCurrentException(log, "Error loading config from '" + config_path + "'");
return;
}
config_processor.savePreprocessedConfig(loaded_config, preprocessed_dir);
/** We should remember last modification time if and only if config was successfully loaded
* Otherwise a race condition could occur during config files update:
* File is contain raw (and non-valid) data, therefore config is not applied.
* When file has been written (and contain valid data), we don't load new data since modification time remains the same.
*/
if (!loaded_config.loaded_from_preprocessed)
{
files = std::move(new_files);
need_reload_from_zk = false;
}
LOG_DEBUG(log, "Loaded config '{}', performing update on configuration", config_path);
try
{
updater(loaded_config.configuration, initial_loading);
}
catch (...)
{
if (throw_on_error)
throw;
tryLogCurrentException(log, "Error updating configuration from '" + config_path + "' config.");
return;
}
LOG_DEBUG(log, "Loaded config '{}', performed update on configuration", config_path);
}
}
struct ConfigReloader::FileWithTimestamp
{
std::string path;
fs::file_time_type modification_time;
explicit FileWithTimestamp(const std::string & path_)
: path(path_), modification_time(fs::last_write_time(path_)) {}
bool operator < (const FileWithTimestamp & rhs) const
{
return path < rhs.path;
}
static bool isTheSame(const FileWithTimestamp & lhs, const FileWithTimestamp & rhs)
{
return (lhs.modification_time == rhs.modification_time) && (lhs.path == rhs.path);
}
};
void ConfigReloader::FilesChangesTracker::addIfExists(const std::string & path_to_add)
{
if (!path_to_add.empty() && fs::exists(path_to_add))
files.emplace(path_to_add);
}
bool ConfigReloader::FilesChangesTracker::isDifferOrNewerThan(const FilesChangesTracker & rhs)
{
return (files.size() != rhs.files.size()) ||
!std::equal(files.begin(), files.end(), rhs.files.begin(), FileWithTimestamp::isTheSame);
}
ConfigReloader::FilesChangesTracker ConfigReloader::getNewFileList() const
{
FilesChangesTracker file_list;
file_list.addIfExists(config_path);
for (const std::string& path : extra_paths)
file_list.addIfExists(path);
for (const auto & merge_path : ConfigProcessor::getConfigMergeFiles(config_path))
file_list.addIfExists(merge_path);
return file_list;
}
}
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