ClickHouse/base/daemon/BaseDaemon.cpp
2020-12-22 20:13:18 +03:00

1001 lines
32 KiB
C++

#include <daemon/BaseDaemon.h>
#include <daemon/SentryWriter.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <sys/resource.h>
#if defined(__linux__)
#include <sys/prctl.h>
#endif
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <cxxabi.h>
#include <unistd.h>
#include <typeinfo>
#include <iostream>
#include <fstream>
#include <sstream>
#include <memory>
#include <ext/scope_guard.h>
#include <Poco/Observer.h>
#include <Poco/AutoPtr.h>
#include <Poco/PatternFormatter.h>
#include <Poco/File.h>
#include <Poco/Path.h>
#include <Poco/Message.h>
#include <Poco/Util/Application.h>
#include <Poco/Exception.h>
#include <Poco/ErrorHandler.h>
#include <Poco/Condition.h>
#include <Poco/SyslogChannel.h>
#include <Poco/DirectoryIterator.h>
#include <common/logger_useful.h>
#include <common/ErrorHandlers.h>
#include <common/argsToConfig.h>
#include <common/getThreadId.h>
#include <common/coverage.h>
#include <common/sleep.h>
#include <IO/WriteBufferFromFile.h>
#include <IO/WriteBufferFromFileDescriptorDiscardOnFailure.h>
#include <IO/ReadBufferFromFileDescriptor.h>
#include <IO/ReadHelpers.h>
#include <IO/WriteHelpers.h>
#include <Common/Exception.h>
#include <Common/PipeFDs.h>
#include <Common/StackTrace.h>
#include <Common/getMultipleKeysFromConfig.h>
#include <Common/ClickHouseRevision.h>
#include <Common/Config/ConfigProcessor.h>
#include <Common/MemorySanitizer.h>
#include <Common/SymbolIndex.h>
#if !defined(ARCADIA_BUILD)
# include <Common/config_version.h>
#endif
#if defined(OS_DARWIN)
# pragma GCC diagnostic ignored "-Wunused-macros"
# define _XOPEN_SOURCE 700 // ucontext is not available without _XOPEN_SOURCE
#endif
#include <ucontext.h>
DB::PipeFDs signal_pipe;
/** Reset signal handler to the default and send signal to itself.
* It's called from user signal handler to write core dump.
*/
static void call_default_signal_handler(int sig)
{
signal(sig, SIG_DFL);
raise(sig);
}
const char * msan_strsignal(int sig)
{
// Apparently strsignal is not instrumented by MemorySanitizer, so we
// have to unpoison it to avoid msan reports inside fmt library when we
// print it.
const char * signal_name = strsignal(sig);
__msan_unpoison_string(signal_name);
return signal_name;
}
static constexpr size_t max_query_id_size = 127;
static const size_t signal_pipe_buf_size =
sizeof(int)
+ sizeof(siginfo_t)
+ sizeof(ucontext_t)
+ sizeof(StackTrace)
+ sizeof(UInt32)
+ max_query_id_size + 1 /// query_id + varint encoded length
+ sizeof(void*);
using signal_function = void(int, siginfo_t*, void*);
static void writeSignalIDtoSignalPipe(int sig)
{
auto saved_errno = errno; /// We must restore previous value of errno in signal handler.
char buf[signal_pipe_buf_size];
DB::WriteBufferFromFileDescriptor out(signal_pipe.fds_rw[1], signal_pipe_buf_size, buf);
DB::writeBinary(sig, out);
out.next();
errno = saved_errno;
}
/** Signal handler for HUP / USR1 */
static void closeLogsSignalHandler(int sig, siginfo_t *, void *)
{
writeSignalIDtoSignalPipe(sig);
}
static void terminateRequestedSignalHandler(int sig, siginfo_t *, void *)
{
writeSignalIDtoSignalPipe(sig);
}
/** Handler for "fault" or diagnostic signals. Send data about fault to separate thread to write into log.
*/
static void signalHandler(int sig, siginfo_t * info, void * context)
{
auto saved_errno = errno; /// We must restore previous value of errno in signal handler.
char buf[signal_pipe_buf_size];
DB::WriteBufferFromFileDescriptorDiscardOnFailure out(signal_pipe.fds_rw[1], signal_pipe_buf_size, buf);
const ucontext_t signal_context = *reinterpret_cast<ucontext_t *>(context);
const StackTrace stack_trace(signal_context);
StringRef query_id = DB::CurrentThread::getQueryId(); /// This is signal safe.
query_id.size = std::min(query_id.size, max_query_id_size);
DB::writeBinary(sig, out);
DB::writePODBinary(*info, out);
DB::writePODBinary(signal_context, out);
DB::writePODBinary(stack_trace, out);
DB::writeBinary(UInt32(getThreadId()), out);
DB::writeStringBinary(query_id, out);
DB::writePODBinary(DB::current_thread, out);
out.next();
if (sig != SIGTSTP) /// This signal is used for debugging.
{
/// The time that is usually enough for separate thread to print info into log.
sleepForSeconds(10);
call_default_signal_handler(sig);
}
errno = saved_errno;
}
/// Avoid link time dependency on DB/Interpreters - will use this function only when linked.
__attribute__((__weak__)) void collectCrashLog(
Int32 signal, UInt64 thread_id, const String & query_id, const StackTrace & stack_trace);
/** The thread that read info about signal or std::terminate from pipe.
* On HUP / USR1, close log files (for new files to be opened later).
* On information about std::terminate, write it to log.
* On other signals, write info to log.
*/
class SignalListener : public Poco::Runnable
{
public:
enum Signals : int
{
StdTerminate = -1,
StopThread = -2,
SanitizerTrap = -3,
};
explicit SignalListener(BaseDaemon & daemon_)
: log(&Poco::Logger::get("BaseDaemon"))
, daemon(daemon_)
{
}
void run() override
{
char buf[signal_pipe_buf_size];
DB::ReadBufferFromFileDescriptor in(signal_pipe.fds_rw[0], signal_pipe_buf_size, buf);
while (!in.eof())
{
int sig = 0;
DB::readBinary(sig, in);
// We may log some specific signals afterwards, with different log
// levels and more info, but for completeness we log all signals
// here at trace level.
// Don't use strsignal here, because it's not thread-safe.
LOG_TRACE(log, "Received signal {}", sig);
if (sig == Signals::StopThread)
{
LOG_INFO(log, "Stop SignalListener thread");
break;
}
else if (sig == SIGHUP || sig == SIGUSR1)
{
LOG_DEBUG(log, "Received signal to close logs.");
BaseDaemon::instance().closeLogs(BaseDaemon::instance().logger());
LOG_INFO(log, "Opened new log file after received signal.");
}
else if (sig == Signals::StdTerminate)
{
UInt32 thread_num;
std::string message;
DB::readBinary(thread_num, in);
DB::readBinary(message, in);
onTerminate(message, thread_num);
}
else if (sig == SIGINT ||
sig == SIGQUIT ||
sig == SIGTERM)
{
daemon.handleSignal(sig);
}
else
{
siginfo_t info;
ucontext_t context;
StackTrace stack_trace(NoCapture{});
UInt32 thread_num;
std::string query_id;
DB::ThreadStatus * thread_ptr{};
if (sig != SanitizerTrap)
{
DB::readPODBinary(info, in);
DB::readPODBinary(context, in);
}
DB::readPODBinary(stack_trace, in);
DB::readBinary(thread_num, in);
DB::readBinary(query_id, in);
DB::readPODBinary(thread_ptr, in);
/// This allows to receive more signals if failure happens inside onFault function.
/// Example: segfault while symbolizing stack trace.
std::thread([=, this] { onFault(sig, info, context, stack_trace, thread_num, query_id, thread_ptr); }).detach();
}
}
}
private:
Poco::Logger * log;
BaseDaemon & daemon;
void onTerminate(const std::string & message, UInt32 thread_num) const
{
LOG_FATAL(log, "(version {}{}, {}) (from thread {}) {}",
VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info, thread_num, message);
}
void onFault(
int sig,
const siginfo_t & info,
const ucontext_t & context,
const StackTrace & stack_trace,
UInt32 thread_num,
const std::string & query_id,
DB::ThreadStatus * thread_ptr) const
{
DB::ThreadStatus thread_status;
/// Send logs from this thread to client if possible.
/// It will allow client to see failure messages directly.
if (thread_ptr)
{
if (auto logs_queue = thread_ptr->getInternalTextLogsQueue())
DB::CurrentThread::attachInternalTextLogsQueue(logs_queue, DB::LogsLevel::trace);
}
LOG_FATAL(log, "########################################");
if (query_id.empty())
{
LOG_FATAL(log, "(version {}{}, {}) (from thread {}) (no query) Received signal {} ({})",
VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info,
thread_num, msan_strsignal(sig), sig);
}
else
{
LOG_FATAL(log, "(version {}{}, {}) (from thread {}) (query_id: {}) Received signal {} ({})",
VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info,
thread_num, query_id, msan_strsignal(sig), sig);
}
String error_message;
if (sig != SanitizerTrap)
error_message = signalToErrorMessage(sig, info, context);
else
error_message = "Sanitizer trap.";
LOG_FATAL(log, error_message);
if (stack_trace.getSize())
{
/// Write bare stack trace (addresses) just in case if we will fail to print symbolized stack trace.
/// NOTE This still require memory allocations and mutex lock inside logger. BTW we can also print it to stderr using write syscalls.
std::stringstream bare_stacktrace;
bare_stacktrace << "Stack trace:";
for (size_t i = stack_trace.getOffset(); i < stack_trace.getSize(); ++i)
bare_stacktrace << ' ' << stack_trace.getFramePointers()[i];
LOG_FATAL(log, bare_stacktrace.str());
}
/// Write symbolized stack trace line by line for better grep-ability.
stack_trace.toStringEveryLine([&](const std::string & s) { LOG_FATAL(log, s); });
/// Write crash to system.crash_log table if available.
if (collectCrashLog)
collectCrashLog(sig, thread_num, query_id, stack_trace);
/// Send crash report to developers (if configured)
if (sig != SanitizerTrap)
SentryWriter::onFault(sig, error_message, stack_trace);
/// When everything is done, we will try to send these error messages to client.
if (thread_ptr)
thread_ptr->onFatalError();
}
};
#if defined(SANITIZER)
extern "C" void __sanitizer_set_death_callback(void (*)());
static void sanitizerDeathCallback()
{
/// Also need to send data via pipe. Otherwise it may lead to deadlocks or failures in printing diagnostic info.
char buf[signal_pipe_buf_size];
DB::WriteBufferFromFileDescriptorDiscardOnFailure out(signal_pipe.fds_rw[1], signal_pipe_buf_size, buf);
const StackTrace stack_trace;
StringRef query_id = DB::CurrentThread::getQueryId();
query_id.size = std::min(query_id.size, max_query_id_size);
int sig = SignalListener::SanitizerTrap;
DB::writeBinary(sig, out);
DB::writePODBinary(stack_trace, out);
DB::writeBinary(UInt32(getThreadId()), out);
DB::writeStringBinary(query_id, out);
DB::writePODBinary(DB::current_thread, out);
out.next();
/// The time that is usually enough for separate thread to print info into log.
sleepForSeconds(10);
}
#endif
/** To use with std::set_terminate.
* Collects slightly more info than __gnu_cxx::__verbose_terminate_handler,
* and send it to pipe. Other thread will read this info from pipe and asynchronously write it to log.
* Look at libstdc++-v3/libsupc++/vterminate.cc for example.
*/
[[noreturn]] static void terminate_handler()
{
static thread_local bool terminating = false;
if (terminating)
abort();
terminating = true;
std::string log_message;
if (std::current_exception())
log_message = "Terminate called for uncaught exception:\n" + DB::getCurrentExceptionMessage(true);
else
log_message = "Terminate called without an active exception";
static const size_t buf_size = 1024;
if (log_message.size() > buf_size - 16)
log_message.resize(buf_size - 16);
char buf[buf_size];
DB::WriteBufferFromFileDescriptor out(signal_pipe.fds_rw[1], buf_size, buf);
DB::writeBinary(static_cast<int>(SignalListener::StdTerminate), out);
DB::writeBinary(UInt32(getThreadId()), out);
DB::writeBinary(log_message, out);
out.next();
abort();
}
static std::string createDirectory(const std::string & file)
{
auto path = Poco::Path(file).makeParent();
if (path.toString().empty())
return "";
Poco::File(path).createDirectories();
return path.toString();
};
static bool tryCreateDirectories(Poco::Logger * logger, const std::string & path)
{
try
{
Poco::File(path).createDirectories();
return true;
}
catch (...)
{
LOG_WARNING(logger, "{}: when creating {}, {}", __PRETTY_FUNCTION__, path, DB::getCurrentExceptionMessage(true));
}
return false;
}
void BaseDaemon::reloadConfiguration()
{
/** If the program is not run in daemon mode and 'config-file' is not specified,
* then we use config from 'config.xml' file in current directory,
* but will log to console (or use parameters --log-file, --errorlog-file from command line)
* instead of using files specified in config.xml.
* (It's convenient to log in console when you start server without any command line parameters.)
*/
config_path = config().getString("config-file", "config.xml");
DB::ConfigProcessor config_processor(config_path, false, true);
config_processor.setConfigPath(Poco::Path(config_path).makeParent().toString());
loaded_config = config_processor.loadConfig(/* allow_zk_includes = */ true);
if (last_configuration != nullptr)
config().removeConfiguration(last_configuration);
last_configuration = loaded_config.configuration.duplicate();
config().add(last_configuration, PRIO_DEFAULT, false);
}
BaseDaemon::BaseDaemon() = default;
BaseDaemon::~BaseDaemon()
{
writeSignalIDtoSignalPipe(SignalListener::StopThread);
signal_listener_thread.join();
/// Reset signals to SIG_DFL to avoid trying to write to the signal_pipe that will be closed after.
for (int sig : handled_signals)
{
signal(sig, SIG_DFL);
}
signal_pipe.close();
}
void BaseDaemon::terminate()
{
if (::raise(SIGTERM) != 0)
throw Poco::SystemException("cannot terminate process");
}
void BaseDaemon::kill()
{
dumpCoverageReportIfPossible();
pid_file.reset();
if (::raise(SIGKILL) != 0)
throw Poco::SystemException("cannot kill process");
}
std::string BaseDaemon::getDefaultCorePath() const
{
return "/opt/cores/";
}
void BaseDaemon::closeFDs()
{
#if defined(OS_FREEBSD) || defined(OS_DARWIN)
Poco::File proc_path{"/dev/fd"};
#else
Poco::File proc_path{"/proc/self/fd"};
#endif
if (proc_path.isDirectory()) /// Hooray, proc exists
{
std::vector<std::string> fds;
/// in /proc/self/fd directory filenames are numeric file descriptors
proc_path.list(fds);
for (const auto & fd_str : fds)
{
int fd = DB::parse<int>(fd_str);
if (fd > 2 && fd != signal_pipe.fds_rw[0] && fd != signal_pipe.fds_rw[1])
::close(fd);
}
}
else
{
int max_fd = -1;
#if defined(_SC_OPEN_MAX)
max_fd = sysconf(_SC_OPEN_MAX);
if (max_fd == -1)
#endif
max_fd = 256; /// bad fallback
for (int fd = 3; fd < max_fd; ++fd)
if (fd != signal_pipe.fds_rw[0] && fd != signal_pipe.fds_rw[1])
::close(fd);
}
}
namespace
{
/// In debug version on Linux, increase oom score so that clickhouse is killed
/// first, instead of some service. Use a carefully chosen random score of 555:
/// the maximum is 1000, and chromium uses 300 for its tab processes. Ignore
/// whatever errors that occur, because it's just a debugging aid and we don't
/// care if it breaks.
#if defined(OS_LINUX) && !defined(NDEBUG)
void debugIncreaseOOMScore()
{
const std::string new_score = "555";
try
{
DB::WriteBufferFromFile buf("/proc/self/oom_score_adj");
buf.write(new_score.c_str(), new_score.size());
}
catch (const Poco::Exception & e)
{
LOG_WARNING(&Poco::Logger::root(), "Failed to adjust OOM score: '{}'.", e.displayText());
return;
}
LOG_INFO(&Poco::Logger::root(), "Set OOM score adjustment to {}", new_score);
}
#else
void debugIncreaseOOMScore() {}
#endif
}
void BaseDaemon::initialize(Application & self)
{
closeFDs();
ServerApplication::initialize(self);
/// now highest priority (lowest value) is PRIO_APPLICATION = -100, we want higher!
argsToConfig(argv(), config(), PRIO_APPLICATION - 100);
bool is_daemon = config().getBool("application.runAsDaemon", false);
if (is_daemon)
{
/** When creating pid file and looking for config, will search for paths relative to the working path of the program when started.
*/
std::string path = Poco::Path(config().getString("application.path")).setFileName("").toString();
if (0 != chdir(path.c_str()))
throw Poco::Exception("Cannot change directory to " + path);
}
reloadConfiguration();
/// This must be done before creation of any files (including logs).
mode_t umask_num = 0027;
if (config().has("umask"))
{
std::string umask_str = config().getString("umask");
std::stringstream stream;
stream << umask_str;
stream >> std::oct >> umask_num;
}
umask(umask_num);
DB::ConfigProcessor(config_path).savePreprocessedConfig(loaded_config, "");
/// Write core dump on crash.
{
struct rlimit rlim;
if (getrlimit(RLIMIT_CORE, &rlim))
throw Poco::Exception("Cannot getrlimit");
/// 1 GiB by default. If more - it writes to disk too long.
rlim.rlim_cur = config().getUInt64("core_dump.size_limit", 1024 * 1024 * 1024);
if (rlim.rlim_cur && setrlimit(RLIMIT_CORE, &rlim))
{
/// It doesn't work under address/thread sanitizer. http://lists.llvm.org/pipermail/llvm-bugs/2013-April/027880.html
std::cerr << "Cannot set max size of core file to " + std::to_string(rlim.rlim_cur) << std::endl;
}
}
/// This must be done before any usage of DateLUT. In particular, before any logging.
if (config().has("timezone"))
{
const std::string config_timezone = config().getString("timezone");
if (0 != setenv("TZ", config_timezone.data(), 1))
throw Poco::Exception("Cannot setenv TZ variable");
tzset();
DateLUT::setDefaultTimezone(config_timezone);
}
std::string log_path = config().getString("logger.log", "");
if (!log_path.empty())
log_path = Poco::Path(log_path).setFileName("").toString();
/** Redirect stdout, stderr to separate files in the log directory (or in the specified file).
* Some libraries write to stderr in case of errors in debug mode,
* and this output makes sense even if the program is run in daemon mode.
* We have to do it before buildLoggers, for errors on logger initialization will be written to these files.
* If logger.stderr is specified then stderr will be forcibly redirected to that file.
*/
if ((!log_path.empty() && is_daemon) || config().has("logger.stderr"))
{
std::string stderr_path = config().getString("logger.stderr", log_path + "/stderr.log");
if (!freopen(stderr_path.c_str(), "a+", stderr))
throw Poco::OpenFileException("Cannot attach stderr to " + stderr_path);
/// Disable buffering for stderr
setbuf(stderr, nullptr);
}
if ((!log_path.empty() && is_daemon) || config().has("logger.stdout"))
{
std::string stdout_path = config().getString("logger.stdout", log_path + "/stdout.log");
if (!freopen(stdout_path.c_str(), "a+", stdout))
throw Poco::OpenFileException("Cannot attach stdout to " + stdout_path);
}
/// Change path for logging.
if (!log_path.empty())
{
std::string path = createDirectory(log_path);
if (is_daemon
&& chdir(path.c_str()) != 0)
throw Poco::Exception("Cannot change directory to " + path);
}
else
{
if (is_daemon
&& chdir("/tmp") != 0)
throw Poco::Exception("Cannot change directory to /tmp");
}
/// sensitive data masking rules are not used here
buildLoggers(config(), logger(), self.commandName());
/// After initialized loggers but before initialized signal handling.
if (should_setup_watchdog)
setupWatchdog();
/// Create pid file.
if (config().has("pid"))
pid_file.emplace(config().getString("pid"), DB::StatusFile::write_pid);
if (is_daemon)
{
/** Change working directory to the directory to write core dumps.
* We have to do it after buildLoggers, because there is the case when config files was in current directory.
*/
std::string core_path = config().getString("core_path", "");
if (core_path.empty())
core_path = getDefaultCorePath();
tryCreateDirectories(&logger(), core_path);
Poco::File cores = core_path;
if (!(cores.exists() && cores.isDirectory()))
{
core_path = !log_path.empty() ? log_path : "/opt/";
tryCreateDirectories(&logger(), core_path);
}
if (0 != chdir(core_path.c_str()))
throw Poco::Exception("Cannot change directory to " + core_path);
}
initializeTerminationAndSignalProcessing();
logRevision();
debugIncreaseOOMScore();
for (const auto & key : DB::getMultipleKeysFromConfig(config(), "", "graphite"))
{
graphite_writers.emplace(key, std::make_unique<GraphiteWriter>(key));
}
}
static void addSignalHandler(const std::vector<int> & signals, signal_function handler, std::vector<int> * out_handled_signals)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = handler;
sa.sa_flags = SA_SIGINFO;
#if defined(OS_DARWIN)
sigemptyset(&sa.sa_mask);
for (auto signal : signals)
sigaddset(&sa.sa_mask, signal);
#else
if (sigemptyset(&sa.sa_mask))
throw Poco::Exception("Cannot set signal handler.");
for (auto signal : signals)
if (sigaddset(&sa.sa_mask, signal))
throw Poco::Exception("Cannot set signal handler.");
#endif
for (auto signal : signals)
if (sigaction(signal, &sa, nullptr))
throw Poco::Exception("Cannot set signal handler.");
if (out_handled_signals)
std::copy(signals.begin(), signals.end(), std::back_inserter(*out_handled_signals));
};
static void blockSignals(const std::vector<int> & signals)
{
sigset_t sig_set;
#if defined(OS_DARWIN)
sigemptyset(&sig_set);
for (auto signal : signals)
sigaddset(&sig_set, signal);
#else
if (sigemptyset(&sig_set))
throw Poco::Exception("Cannot block signal.");
for (auto signal : signals)
if (sigaddset(&sig_set, signal))
throw Poco::Exception("Cannot block signal.");
#endif
if (pthread_sigmask(SIG_BLOCK, &sig_set, nullptr))
throw Poco::Exception("Cannot block signal.");
};
void BaseDaemon::initializeTerminationAndSignalProcessing()
{
SentryWriter::initialize(config());
std::set_terminate(terminate_handler);
/// We want to avoid SIGPIPE when working with sockets and pipes, and just handle return value/errno instead.
blockSignals({SIGPIPE});
/// Setup signal handlers.
/// SIGTSTP is added for debugging purposes. To output a stack trace of any running thread at anytime.
addSignalHandler({SIGABRT, SIGSEGV, SIGILL, SIGBUS, SIGSYS, SIGFPE, SIGPIPE, SIGTSTP}, signalHandler, &handled_signals);
addSignalHandler({SIGHUP, SIGUSR1}, closeLogsSignalHandler, &handled_signals);
addSignalHandler({SIGINT, SIGQUIT, SIGTERM}, terminateRequestedSignalHandler, &handled_signals);
#if defined(SANITIZER)
__sanitizer_set_death_callback(sanitizerDeathCallback);
#endif
/// Set up Poco ErrorHandler for Poco Threads.
static KillingErrorHandler killing_error_handler;
Poco::ErrorHandler::set(&killing_error_handler);
signal_pipe.setNonBlockingWrite();
signal_pipe.tryIncreaseSize(1 << 20);
signal_listener = std::make_unique<SignalListener>(*this);
signal_listener_thread.start(*signal_listener);
#if defined(__ELF__) && !defined(__FreeBSD__)
String build_id_hex = DB::SymbolIndex::instance()->getBuildIDHex();
if (build_id_hex.empty())
build_id_info = "no build id";
else
build_id_info = "build id: " + build_id_hex;
#else
build_id_info = "no build id";
#endif
}
void BaseDaemon::logRevision() const
{
Poco::Logger::root().information("Starting " + std::string{VERSION_FULL}
+ " with revision " + std::to_string(ClickHouseRevision::getVersionRevision())
+ ", " + build_id_info
+ ", PID " + std::to_string(getpid()));
}
void BaseDaemon::defineOptions(Poco::Util::OptionSet & new_options)
{
new_options.addOption(
Poco::Util::Option("config-file", "C", "load configuration from a given file")
.required(false)
.repeatable(false)
.argument("<file>")
.binding("config-file"));
new_options.addOption(
Poco::Util::Option("log-file", "L", "use given log file")
.required(false)
.repeatable(false)
.argument("<file>")
.binding("logger.log"));
new_options.addOption(
Poco::Util::Option("errorlog-file", "E", "use given log file for errors only")
.required(false)
.repeatable(false)
.argument("<file>")
.binding("logger.errorlog"));
new_options.addOption(
Poco::Util::Option("pid-file", "P", "use given pidfile")
.required(false)
.repeatable(false)
.argument("<file>")
.binding("pid"));
Poco::Util::ServerApplication::defineOptions(new_options);
}
void BaseDaemon::handleSignal(int signal_id)
{
if (signal_id == SIGINT ||
signal_id == SIGQUIT ||
signal_id == SIGTERM)
{
std::unique_lock<std::mutex> lock(signal_handler_mutex);
{
++terminate_signals_counter;
sigint_signals_counter += signal_id == SIGINT;
signal_event.notify_all();
}
onInterruptSignals(signal_id);
}
else
throw DB::Exception(std::string("Unsupported signal: ") + msan_strsignal(signal_id), 0);
}
void BaseDaemon::onInterruptSignals(int signal_id)
{
is_cancelled = true;
LOG_INFO(&logger(), "Received termination signal ({})", msan_strsignal(signal_id));
if (sigint_signals_counter >= 2)
{
LOG_INFO(&logger(), "Received second signal Interrupt. Immediately terminate.");
call_default_signal_handler(signal_id);
/// If the above did not help.
_exit(128 + signal_id);
}
}
void BaseDaemon::waitForTerminationRequest()
{
/// NOTE: as we already process signals via pipe, we don't have to block them with sigprocmask in threads
std::unique_lock<std::mutex> lock(signal_handler_mutex);
signal_event.wait(lock, [this](){ return terminate_signals_counter > 0; });
}
void BaseDaemon::shouldSetupWatchdog(char * argv0_)
{
should_setup_watchdog = true;
argv0 = argv0_;
}
void BaseDaemon::setupWatchdog()
{
/// Initialize in advance to avoid double initialization in forked processes.
DateLUT::instance();
std::string original_process_name;
if (argv0)
original_process_name = argv0;
while (true)
{
static pid_t pid = -1;
pid = fork();
if (-1 == pid)
throw Poco::Exception("Cannot fork");
if (0 == pid)
{
logger().information("Forked a child process to watch");
#if defined(__linux__)
if (0 != prctl(PR_SET_PDEATHSIG, SIGKILL))
logger().warning("Cannot do prctl to ask termination with parent.");
#endif
return;
}
/// Change short thread name and process name.
setThreadName("clckhouse-watch"); /// 15 characters
if (argv0)
{
const char * new_process_name = "clickhouse-watchdog";
memset(argv0, 0, original_process_name.size());
memcpy(argv0, new_process_name, std::min(strlen(new_process_name), original_process_name.size()));
}
logger().information(fmt::format("Will watch for the process with pid {}", pid));
/// Forward signals to the child process.
addSignalHandler(
{SIGHUP, SIGUSR1, SIGINT, SIGQUIT, SIGTERM},
[](int sig, siginfo_t *, void *)
{
/// Forward all signals except INT as it can be send by terminal to the process group when user press Ctrl+C,
/// and we process double delivery of this signal as immediate termination.
if (sig == SIGINT)
return;
const char * error_message = "Cannot forward signal to the child process.\n";
if (0 != ::kill(pid, sig))
{
auto res = write(STDERR_FILENO, error_message, strlen(error_message));
(void)res;
}
},
nullptr);
int status = 0;
do
{
if (-1 != waitpid(pid, &status, WUNTRACED | WCONTINUED) || errno == ECHILD)
{
if (WIFSTOPPED(status))
logger().warning(fmt::format("Child process was stopped by signal {}.", WSTOPSIG(status)));
else if (WIFCONTINUED(status))
logger().warning(fmt::format("Child process was continued."));
else
break;
}
else if (errno != EINTR)
throw Poco::Exception("Cannot waitpid, errno: " + std::string(strerror(errno)));
} while (true);
if (errno == ECHILD)
{
logger().information("Child process no longer exists.");
_exit(status);
}
if (WIFEXITED(status))
{
logger().information(fmt::format("Child process exited normally with code {}.", WEXITSTATUS(status)));
_exit(status);
}
if (WIFSIGNALED(status))
{
int sig = WTERMSIG(status);
if (sig == SIGKILL)
{
logger().fatal(fmt::format("Child process was terminated by signal {} (KILL)."
" If it is not done by 'forcestop' command or manually,"
" the possible cause is OOM Killer (see 'dmesg' and look at the '/var/log/kern.log' for the details).", sig));
}
else
{
logger().fatal(fmt::format("Child process was terminated by signal {}.", sig));
if (sig == SIGINT || sig == SIGTERM || sig == SIGQUIT)
_exit(status);
}
}
else
{
logger().fatal("Child process was not exited normally by unknown reason.");
}
/// Automatic restart is not enabled but you can play with it.
#if 1
_exit(status);
#else
logger().information("Will restart.");
if (argv0)
memcpy(argv0, original_process_name.c_str(), original_process_name.size());
#endif
}
}