Hawkin
/
arangodb
mirror of https://gitee.com/bigwinds/arangodb
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
arangodb/lib/ApplicationFeatures/SupervisorFeature.cpp

400 lines
11 KiB
C++
Raw Blame History

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2016 ArangoDB 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 ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#include "SupervisorFeature.h"
#include "Basics/process-utils.h"
#include "ApplicationFeatures/DaemonFeature.h"
#include "Basics/ArangoGlobalContext.h"
#include "Logger/LogAppender.h"
#include "Logger/Logger.h"
#include "Logger/LoggerFeature.h"
#include "ProgramOptions/ProgramOptions.h"
#include "ProgramOptions/Section.h"
#ifdef TRI_HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif
#ifdef TRI_HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef TRI_HAVE_SIGNAL_H
#include <signal.h>
#endif
#include <sys/types.h>
#ifdef TRI_HAVE_UNISTD_H
#include <unistd.h>
#endif
using namespace arangodb;
using namespace arangodb::application_features;
using namespace arangodb::basics;
using namespace arangodb::options;
namespace {
static bool DONE = false;
static int CLIENT_PID = false;
static char const* restartMessage = "will now start a new child process";
static char const* noRestartMessage =
"will intentionally not start a new child process";
static char const* fixErrorMessage =
"please check what causes the child process to fail and fix the error "
"first";
static char const* translateSignal(int signal) {
if (signal >= 128) {
signal -= 128;
}
switch (signal) {
#ifdef SIGHUP
case SIGHUP:
return "SIGHUP";
#endif
#ifdef SIGINT
case SIGINT:
return "SIGINT";
#endif
#ifdef SIGQUIT
case SIGQUIT:
return "SIGQUIT";
#endif
#ifdef SIGKILL
case SIGILL:
return "SIGILL";
#endif
#ifdef SIGTRAP
case SIGTRAP:
return "SIGTRAP";
#endif
#ifdef SIGABRT
case SIGABRT:
return "SIGABRT";
#endif
#ifdef SIGBUS
case SIGBUS:
return "SIGBUS";
#endif
#ifdef SIGFPE
case SIGFPE:
return "SIGFPE";
#endif
#ifdef SIGKILL
case SIGKILL:
return "SIGKILL";
#endif
#ifdef SIGSEGV
case SIGSEGV:
return "SIGSEGV";
#endif
#ifdef SIGPIPE
case SIGPIPE:
return "SIGPIPE";
#endif
#ifdef SIGTERM
case SIGTERM:
return "SIGTERM";
#endif
#ifdef SIGCONT
case SIGCONT:
return "SIGCONT";
#endif
#ifdef SIGSTOP
case SIGSTOP:
return "SIGSTOP";
#endif
default:
return "unknown";
}
}
static void StopHandler(int) {
LOG_TOPIC("3ca0f", INFO, Logger::STARTUP)
<< "received SIGINT for supervisor; commanding client [" << CLIENT_PID
<< "] to shut down.";
int rc = kill(CLIENT_PID, SIGTERM);
if (rc < 0) {
LOG_TOPIC("cf204", ERR, Logger::STARTUP)
<< "commanding client [" << CLIENT_PID << "] to shut down failed: ["
<< errno << "] " << strerror(errno);
}
DONE = true;
}
} // namespace
static void HUPHandler(int) {
LOG_TOPIC("a7bac", INFO, Logger::STARTUP)
<< "received SIGHUP for supervisor; commanding client [" << CLIENT_PID
<< "] to logrotate.";
int rc = kill(CLIENT_PID, SIGHUP);
if (rc < 0) {
LOG_TOPIC("e7d53", ERR, Logger::STARTUP)
<< "commanding client [" << CLIENT_PID << "] to logrotate failed: ["
<< errno << "] " << strerror(errno);
}
}
SupervisorFeature::SupervisorFeature(application_features::ApplicationServer& server)
: ApplicationFeature(server, "Supervisor"), _supervisor(false), _clientPid(0) {
setOptional(true);
startsAfter("GreetingsPhase");
startsAfter("Daemon");
}
void SupervisorFeature::collectOptions(std::shared_ptr<ProgramOptions> options) {
options->addOption("--supervisor",
"background the server, starts a supervisor",
new BooleanParameter(&_supervisor),
arangodb::options::makeFlags(arangodb::options::Flags::Hidden));
}
void SupervisorFeature::validateOptions(std::shared_ptr<ProgramOptions> options) {
if (_supervisor) {
try {
DaemonFeature* daemon =
ApplicationServer::getFeature<DaemonFeature>("Daemon");
// force daemon mode
daemon->setDaemon(true);
// revalidate options
daemon->validateOptions(options);
} catch (...) {
LOG_TOPIC("9207d", FATAL, arangodb::Logger::FIXME)
<< "daemon mode not available, cannot start supervisor";
FATAL_ERROR_EXIT();
}
}
}
void SupervisorFeature::daemonize() {
static time_t const MIN_TIME_ALIVE_IN_SEC = 30;
if (!_supervisor) {
return;
}
time_t startTime = time(nullptr);
time_t t;
bool done = false;
int result = EXIT_SUCCESS;
// will be reseted in SchedulerFeature
ArangoGlobalContext::CONTEXT->unmaskStandardSignals();
LoggerFeature* logger = nullptr;
try {
logger = ApplicationServer::getFeature<LoggerFeature>("Logger");
} catch (...) {
LOG_TOPIC("4e6ee", FATAL, Logger::STARTUP) << "unknown feature 'Logger', giving up";
FATAL_ERROR_EXIT();
}
logger->setSupervisor(true);
logger->prepare();
LOG_TOPIC("47d80", DEBUG, Logger::STARTUP) << "starting supervisor loop";
while (!done) {
logger->setSupervisor(false);
signal(SIGINT, SIG_DFL);
signal(SIGTERM, SIG_DFL);
LOG_TOPIC("a3331", DEBUG, Logger::STARTUP)
<< "supervisor will now try to fork a new child process";
// fork of the server
_clientPid = fork();
if (_clientPid < 0) {
LOG_TOPIC("dc0e1", FATAL, Logger::STARTUP) << "fork failed, giving up";
FATAL_ERROR_EXIT();
}
// parent (supervisor)
if (0 < _clientPid) {
signal(SIGINT, StopHandler);
signal(SIGTERM, StopHandler);
signal(SIGHUP, HUPHandler);
LOG_TOPIC("ba799", INFO, Logger::STARTUP)
<< "supervisor has forked a child process with pid " << _clientPid;
TRI_SetProcessTitle("arangodb [supervisor]");
LOG_TOPIC("639f2", DEBUG, Logger::STARTUP) << "supervisor mode: within parent";
CLIENT_PID = _clientPid;
DONE = false;
int status;
int res = waitpid(_clientPid, &status, 0);
bool horrible = true;
LOG_TOPIC("a7a71", INFO, Logger::STARTUP)
<< "waitpid woke up with return value " << res << " and status "
<< status << " and DONE = " << (DONE ? "true" : "false");
if (DONE) {
// signal handler for SIGINT or SIGTERM was invoked
done = true;
horrible = false;
} else {
TRI_ASSERT(horrible);
if (WIFEXITED(status)) {
// give information about cause of death
if (WEXITSTATUS(status) == 0) {
LOG_TOPIC("61ac2", INFO, Logger::STARTUP)
<< "child process " << _clientPid << " terminated normally. "
<< noRestartMessage;
done = true;
horrible = false;
} else {
t = time(nullptr) - startTime;
if (t < MIN_TIME_ALIVE_IN_SEC) {
LOG_TOPIC("9db96", ERR, Logger::STARTUP)
<< "child process " << _clientPid
<< " terminated unexpectedly, exit status " << WEXITSTATUS(status)
<< ". the child process only survived for " << t
<< " seconds. this is lower than the minimum threshold value "
"of "
<< MIN_TIME_ALIVE_IN_SEC << " s. " << noRestartMessage << ". "
<< fixErrorMessage;
TRI_ASSERT(horrible);
done = true;
} else {
LOG_TOPIC("1ae4a", ERR, Logger::STARTUP)
<< "child process " << _clientPid << " terminated unexpectedly, exit status "
<< WEXITSTATUS(status) << ". " << restartMessage;
done = false;
}
}
} else if (WIFSIGNALED(status)) {
int const s = WTERMSIG(status);
switch (s) {
case 2: // SIGINT
case 9: // SIGKILL
case 15: // SIGTERM
LOG_TOPIC("50f4e", INFO, Logger::STARTUP)
<< "child process " << _clientPid << " terminated normally, exit status "
<< s << " (" << translateSignal(s) << "). " << noRestartMessage;
done = true;
horrible = false;
break;
default:
TRI_ASSERT(horrible);
t = time(nullptr) - startTime;
if (t < MIN_TIME_ALIVE_IN_SEC) {
LOG_TOPIC("4a3a6", ERR, Logger::STARTUP)
<< "child process " << _clientPid << " terminated unexpectedly, signal "
<< s << " (" << translateSignal(s)
<< "). the child process only survived for " << t
<< " seconds. this is lower than the minimum threshold "
"value of "
<< MIN_TIME_ALIVE_IN_SEC << " s. " << noRestartMessage
<< ". " << fixErrorMessage;
done = true;
#ifdef WCOREDUMP
if (WCOREDUMP(status)) {
LOG_TOPIC("195c5", WARN, Logger::STARTUP)
<< "child process " << _clientPid << " also produced a core dump";
}
#endif
} else {
LOG_TOPIC("97c53", ERR, Logger::STARTUP)
<< "child process " << _clientPid << " terminated unexpectedly, signal "
<< s << " (" << translateSignal(s) << "). " << restartMessage;
done = false;
}
break;
}
} else {
LOG_TOPIC("0f028", ERR, Logger::STARTUP)
<< "child process " << _clientPid
<< " terminated unexpectedly, unknown cause. " << restartMessage;
done = false;
}
}
if (horrible) {
result = EXIT_FAILURE;
} else {
result = EXIT_SUCCESS;
}
}
// child - run the normal boot sequence
else {
Logger::shutdown();
LogAppender::allowStdLogging(false);
DaemonFeature::remapStandardFileDescriptors();
LOG_TOPIC("abe90", DEBUG, Logger::STARTUP) << "supervisor mode: within child";
TRI_SetProcessTitle("arangodb [server]");
#ifdef TRI_HAVE_PRCTL
// force child to stop if supervisor dies
prctl(PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0);
#endif
try {
DaemonFeature* daemon =
ApplicationServer::getFeature<DaemonFeature>("Daemon");
// disable daemon mode
daemon->setDaemon(false);
} catch (...) {
}
return;
}
}
LOG_TOPIC("85f0b", DEBUG, Logger::STARTUP) << "supervisor mode: finished (exit " << result << ")";
Logger::flush();
Logger::shutdown();
exit(result);
}
Reference in New Issue View Git Blame Copy Permalink