ServerState::RoleEnum ServerState::checkServersList (std::string const& id) {
// fetch value at Plan/DBServers
// we need to do this to determine the server's role
const std::string key = "Plan/DBServers";
AgencyComm comm;
AgencyCommResult result;
{
AgencyCommLocker locker("Plan", "READ");
if (locker.successful()) {
result = comm.getValues(key, true);
}
}
if (! result.successful()) {
const std::string endpoints = AgencyComm::getEndpointsString();
LOG_TRACE("Could not fetch configuration from agency endpoints (%s): "
"got status code %d, message: %s, key: %s",
endpoints.c_str(),
result._statusCode,
result.errorMessage().c_str(),
key.c_str());
return ServerState::ROLE_UNDEFINED;
}
ServerState::RoleEnum role = ServerState::ROLE_UNDEFINED;
// check if we can find ourselves in the list returned by the agency
result.parse("Plan/DBServers/", false);
std::map<std::string, AgencyCommResultEntry>::const_iterator it = result._values.find(id);
if (it != result._values.end()) {
// we are in the list. this means we are a primary server
role = ServerState::ROLE_PRIMARY;
}
else {
// check if we are a secondary...
it = result._values.begin();
while (it != result._values.end()) {
const std::string name = triagens::basics::JsonHelper::getStringValue((*it).second._json, "");
if (name == id) {
role = ServerState::ROLE_SECONDARY;
_idOfPrimary = it->first;
break;
}
++it;
}
}
return role;
}
int ServerState::lookupLocalInfoToId (std::string const& localInfo,
std::string& id) {
// fetch value at Plan/DBServers
// we need to do this to determine the server's role
const std::string key = "Target/MapLocalToID";
int count = 0;
while (++count <= 600) {
AgencyComm comm;
AgencyCommResult result;
{
AgencyCommLocker locker("Target", "READ");
if (locker.successful()) {
result = comm.getValues(key, true);
}
}
if (! result.successful()) {
const std::string endpoints = AgencyComm::getEndpointsString();
LOG_DEBUG("Could not fetch configuration from agency endpoints (%s): "
"got status code %d, message: %s, key: %s",
endpoints.c_str(),
result._statusCode,
result.errorMessage().c_str(),
key.c_str());
}
else {
result.parse("Target/MapLocalToID/", false);
std::map<std::string, AgencyCommResultEntry>::const_iterator it = result._values.find(localInfo);
if (it != result._values.end()) {
TRI_json_t const* json = it->second._json;
Json j(TRI_UNKNOWN_MEM_ZONE, json, Json::NOFREE);
id = triagens::basics::JsonHelper::getStringValue(json, "ID", "");
if (id.empty()) {
LOG_ERROR("ID not set!");
return TRI_ERROR_CLUSTER_COULD_NOT_DETERMINE_ID;
}
std::string description
= triagens::basics::JsonHelper::getStringValue(json, "Description", "");
if (! description.empty()) {
setDescription(description);
}
return TRI_ERROR_NO_ERROR;
}
}
sleep(1);
};
return TRI_ERROR_CLUSTER_COULD_NOT_DETERMINE_ID;
}
void ApplicationCluster::close () {
if (! enabled()) {
return;
}
if (_heartbeat != 0) {
_heartbeat->stop();
}
// change into shutdown state
ServerState::instance()->setState(ServerState::STATE_SHUTDOWN);
AgencyComm comm;
comm.sendServerState(0.0);
}
ServerState::RoleEnum ServerState::checkCoordinatorsList (std::string const& id) {
// fetch value at Plan/Coordinators
// we need to do this to determine the server's role
const std::string key = "Plan/Coordinators";
AgencyComm comm;
AgencyCommResult result;
{
AgencyCommLocker locker("Plan", "READ");
if (locker.successful()) {
result = comm.getValues(key, true);
}
}
if (! result.successful()) {
const std::string endpoints = AgencyComm::getEndpointsString();
LOG_TRACE("Could not fetch configuration from agency endpoints (%s): "
"got status code %d, message: %s, key: %s",
endpoints.c_str(),
result._statusCode,
result.errorMessage().c_str(),
key.c_str());
return ServerState::ROLE_UNDEFINED;
}
if (! result.parse("Plan/Coordinators/", false)) {
LOG_TRACE("Got an invalid JSON response for Plan/Coordinators");
return ServerState::ROLE_UNDEFINED;
}
// check if we can find ourselves in the list returned by the agency
std::map<std::string, AgencyCommResultEntry>::const_iterator it = result._values.find(id);
if (it != result._values.end()) {
// we are in the list. this means we are a primary server
return ServerState::ROLE_COORDINATOR;
}
return ServerState::ROLE_UNDEFINED;
}
ServerState::RoleEnum ServerState::getRole () {
std::string id;
std::string info;
{
auto role = loadRole();
if (role != ServerState::ROLE_UNDEFINED || ! _clusterEnabled) {
return role;
}
info = _localInfo;
id = _id;
}
if (id.empty()) {
// We need to announce ourselves in the agency to get a role configured:
LOG_DEBUG("Announcing our birth in Current/NewServers to the agency...");
AgencyComm comm;
AgencyCommResult result;
Json json(Json::Object, 1);
json("endpoint", Json(TRI_UNKNOWN_MEM_ZONE, getAddress()));
std::string description = getDescription();
if (! description.empty()) {
json("Description", Json(TRI_UNKNOWN_MEM_ZONE, description));
}
result = comm.setValue("Current/NewServers/"+_localInfo, json.json(), 0.0);
if (! result.successful()) {
LOG_ERROR("Could not talk to agency!");
return ROLE_UNDEFINED;
}
std::string jsonst = json.toString();
LOG_DEBUG("Have stored %s under Current/NewServers/%s in agency.",
jsonst.c_str(), _localInfo.c_str());
}
// role not yet set
RoleEnum role = determineRole(info, id);
std::string roleString = roleToString(role);
LOG_DEBUG("Found my role: %s", roleString.c_str());
storeRole(role);
return role;
}
RestStatus RestShutdownHandler::execute() {
if (_request->requestType() != rest::RequestType::DELETE_REQ) {
generateError(rest::ResponseCode::METHOD_NOT_ALLOWED, 405);
return RestStatus::DONE;
}
bool removeFromCluster;
std::string const& remove = _request->value("remove_from_cluster", removeFromCluster);
removeFromCluster = removeFromCluster && remove == "1";
bool shutdownClusterFound;
std::string const& shutdownCluster = _request->value("shutdown_cluster", shutdownClusterFound);
if (shutdownClusterFound && shutdownCluster == "1") {
AgencyComm agency;
VPackBuilder builder;
builder.add(VPackValue(true));
AgencyCommResult result = agency.setValue("Shutdown", builder.slice(), 0.0);
if (!result.successful()) {
generateError(rest::ResponseCode::SERVER_ERROR, 500);
return RestStatus::DONE;
}
removeFromCluster = true;
}
if (removeFromCluster) {
ClusterFeature* clusterFeature = ApplicationServer::getFeature<ClusterFeature>("Cluster");
clusterFeature->setUnregisterOnShutdown(true);
}
ApplicationServer::server->beginShutdown();
try {
VPackBuilder result;
result.add(VPackValue("OK"));
generateResult(rest::ResponseCode::OK, result.slice());
} catch (...) {
// Ignore the error
}
return RestStatus::DONE;
}
void ApplicationCluster::stop () {
if (! enabled()) {
return;
}
// change into shutdown state
ServerState::instance()->setState(ServerState::STATE_SHUTDOWN);
AgencyComm comm;
comm.sendServerState(0.0);
if (_heartbeat != 0) {
_heartbeat->stop();
}
{
AgencyCommLocker locker("Current", "WRITE");
if (locker.successful()) {
// unregister ourselves
ServerState::RoleEnum role = ServerState::instance()->getRole();
if (role == ServerState::ROLE_PRIMARY) {
comm.removeValues("Current/DBServers/" + _myId, false);
}
else if (role == ServerState::ROLE_COORDINATOR) {
comm.removeValues("Current/Coordinators/" + _myId, false);
}
// unregister ourselves
comm.removeValues("Current/ServersRegistered/" + _myId, false);
}
}
ClusterComm::cleanup();
ClusterInfo::cleanup();
AgencyComm::cleanup();
}
void ClusterFeature::unprepare() {
if (_enableCluster) {
if (_heartbeatThread != nullptr) {
_heartbeatThread->beginShutdown();
}
// change into shutdown state
ServerState::instance()->setState(ServerState::STATE_SHUTDOWN);
AgencyComm comm;
comm.sendServerState(0.0);
if (_heartbeatThread != nullptr) {
int counter = 0;
while (_heartbeatThread->isRunning()) {
usleep(100000);
// emit warning after 5 seconds
if (++counter == 10 * 5) {
LOG(WARN) << "waiting for heartbeat thread to finish";
}
}
}
if (_unregisterOnShutdown) {
ServerState::instance()->unregister();
}
}
if (!_enableCluster) {
ClusterComm::cleanup();
return;
}
// change into shutdown state
ServerState::instance()->setState(ServerState::STATE_SHUTDOWN);
AgencyComm comm;
comm.sendServerState(0.0);
// Try only once to unregister because maybe the agencycomm
// is shutting down as well...
ServerState::RoleEnum role = ServerState::instance()->getRole();
AgencyWriteTransaction unreg;
// Remove from role
if (role == ServerState::ROLE_PRIMARY) {
unreg.operations.push_back(AgencyOperation(
"Current/DBServers/" + _myId, AgencySimpleOperationType::DELETE_OP));
} else if (role == ServerState::ROLE_COORDINATOR) {
unreg.operations.push_back(AgencyOperation(
"Current/Coordinators/" + _myId, AgencySimpleOperationType::DELETE_OP));
}
// Unregister
unreg.operations.push_back(
AgencyOperation("Current/ServersRegistered/" + _myId,
AgencySimpleOperationType::DELETE_OP));
comm.sendTransactionWithFailover(unreg, 120.0);
while (_heartbeatThread->isRunning()) {
usleep(50000);
}
AgencyComm::cleanup();
ClusterComm::cleanup();
}
void ClusterFeature::start() {
// return if cluster is disabled
if (!_enableCluster) {
return;
}
ServerState::instance()->setState(ServerState::STATE_STARTUP);
// the agency about our state
AgencyComm comm;
comm.sendServerState(0.0);
std::string const version = comm.getVersion();
ServerState::instance()->setInitialized();
std::string const endpoints = AgencyComm::getEndpointsString();
ServerState::RoleEnum role = ServerState::instance()->getRole();
LOG(INFO) << "Cluster feature is turned on. Agency version: " << version
<< ", Agency endpoints: " << endpoints << ", server id: '" << _myId
<< "', internal address: " << _myAddress
<< ", role: " << ServerState::roleToString(role);
if (!_disableHeartbeat) {
AgencyCommResult result = comm.getValues("Sync/HeartbeatIntervalMs");
if (result.successful()) {
velocypack::Slice HeartbeatIntervalMs =
result.slice()[0].get(std::vector<std::string>(
{AgencyComm::prefix(), "Sync", "HeartbeatIntervalMs"}));
if (HeartbeatIntervalMs.isInteger()) {
try {
_heartbeatInterval = HeartbeatIntervalMs.getUInt();
LOG(INFO) << "using heartbeat interval value '" << _heartbeatInterval
<< " ms' from agency";
} catch (...) {
// Ignore if it is not a small int or uint
}
}
}
// no value set in agency. use default
if (_heartbeatInterval == 0) {
_heartbeatInterval = 5000; // 1/s
LOG(WARN) << "unable to read heartbeat interval from agency. Using "
<< "default value '" << _heartbeatInterval << " ms'";
}
// start heartbeat thread
_heartbeatThread = std::make_shared<HeartbeatThread>(
_agencyCallbackRegistry.get(), _heartbeatInterval * 1000, 5,
SchedulerFeature::SCHEDULER->ioService());
if (!_heartbeatThread->init() || !_heartbeatThread->start()) {
LOG(FATAL) << "heartbeat could not connect to agency endpoints ("
<< endpoints << ")";
FATAL_ERROR_EXIT();
}
while (!_heartbeatThread->isReady()) {
// wait until heartbeat is ready
usleep(10000);
}
}
AgencyCommResult result;
while (true) {
VPackBuilder builder;
try {
VPackObjectBuilder b(&builder);
builder.add("endpoint", VPackValue(_myAddress));
} catch (...) {
LOG(FATAL) << "out of memory";
FATAL_ERROR_EXIT();
}
result = comm.setValue("Current/ServersRegistered/" + _myId,
builder.slice(), 0.0);
if (!result.successful()) {
LOG(FATAL) << "unable to register server in agency: http code: "
<< result.httpCode() << ", body: " << result.body();
FATAL_ERROR_EXIT();
} else {
break;
}
sleep(1);
}
if (role == ServerState::ROLE_COORDINATOR) {
ServerState::instance()->setState(ServerState::STATE_SERVING);
} else if (role == ServerState::ROLE_PRIMARY) {
ServerState::instance()->setState(ServerState::STATE_SERVINGASYNC);
} else if (role == ServerState::ROLE_SECONDARY) {
ServerState::instance()->setState(ServerState::STATE_SYNCING);
}
}
static void raceForClusterBootstrap() {
AgencyComm agency;
auto ci = ClusterInfo::instance();
while (true) {
AgencyCommResult result = agency.getValues("Bootstrap");
if (!result.successful()) {
// Error in communication, note that value not found is not an error
LOG_TOPIC(TRACE, Logger::STARTUP)
<< "raceForClusterBootstrap: no agency communication";
sleep(1);
continue;
}
VPackSlice value = result.slice()[0].get(
std::vector<std::string>({agency.prefix(), "Bootstrap"}));
if (value.isString()) {
// key was found and is a string
if (value.copyString().find("done") != std::string::npos) {
// all done, let's get out of here:
LOG_TOPIC(TRACE, Logger::STARTUP)
<< "raceForClusterBootstrap: bootstrap already done";
return;
}
LOG_TOPIC(DEBUG, Logger::STARTUP)
<< "raceForClusterBootstrap: somebody else does the bootstrap";
sleep(1);
continue;
}
// No value set, we try to do the bootstrap ourselves:
VPackBuilder b;
b.add(VPackValue(arangodb::ServerState::instance()->getId()));
result = agency.casValue("Bootstrap", b.slice(), false, 300, 15);
if (!result.successful()) {
LOG_TOPIC(DEBUG, Logger::STARTUP)
<< "raceForClusterBootstrap: lost race, somebody else will bootstrap";
// Cannot get foot into the door, try again later:
sleep(1);
continue;
}
// OK, we handle things now, let's see whether a DBserver is there:
auto dbservers = ci->getCurrentDBServers();
if (dbservers.size() == 0) {
LOG_TOPIC(TRACE, Logger::STARTUP)
<< "raceForClusterBootstrap: no DBservers, waiting";
agency.removeValues("Bootstrap", false);
sleep(1);
continue;
}
LOG_TOPIC(DEBUG, Logger::STARTUP)
<< "raceForClusterBootstrap: race won, we do the bootstrap";
auto vocbase = DatabaseFeature::DATABASE->systemDatabase();
V8DealerFeature::DEALER->loadJavascriptFiles(vocbase, "server/bootstrap/cluster-bootstrap.js", 0);
LOG_TOPIC(DEBUG, Logger::STARTUP)
<< "raceForClusterBootstrap: bootstrap done";
b.clear();
b.add(VPackValue(arangodb::ServerState::instance()->getId() + ": done"));
result = agency.setValue("Bootstrap", b.slice(), 0);
if (result.successful()) {
return;
}
LOG_TOPIC(TRACE, Logger::STARTUP)
<< "raceForClusterBootstrap: could not indicate success";
sleep(1);
}
}
bool ApplicationCluster::open () {
if (! enabled()) {
return true;
}
ServerState::RoleEnum role = ServerState::instance()->getRole();
// tell the agency that we are ready
{
AgencyComm comm;
AgencyCommResult result;
AgencyCommLocker locker("Current", "WRITE");
if (locker.successful()) {
TRI_json_t* ep = TRI_CreateString2CopyJson(TRI_UNKNOWN_MEM_ZONE, _myAddress.c_str(), _myAddress.size());
if (ep == 0) {
locker.unlock();
LOG_FATAL_AND_EXIT("out of memory");
}
TRI_json_t* json = TRI_CreateArray2Json(TRI_UNKNOWN_MEM_ZONE, 1);
if (json == 0) {
TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, ep);
locker.unlock();
LOG_FATAL_AND_EXIT("out of memory");
}
TRI_Insert2ArrayJson(TRI_UNKNOWN_MEM_ZONE, json, "endpoint", ep);
result = comm.setValue("Current/ServersRegistered/" + _myId, json, 0.0);
TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, json);
}
if (! result.successful()) {
locker.unlock();
LOG_FATAL_AND_EXIT("unable to register server in agency: http code: %d, body: %s",
(int) result.httpCode(),
result.body().c_str());
}
if (role == ServerState::ROLE_COORDINATOR) {
TRI_json_t* json = TRI_CreateString2CopyJson(TRI_UNKNOWN_MEM_ZONE, "none", 4);
if (json == 0) {
locker.unlock();
LOG_FATAL_AND_EXIT("out of memory");
}
ServerState::instance()->setState(ServerState::STATE_SERVING);
// register coordinator
AgencyCommResult result = comm.setValue("Current/Coordinators/" + _myId, json, 0.0);
TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, json);
if (! result.successful()) {
locker.unlock();
LOG_FATAL_AND_EXIT("unable to register coordinator in agency");
}
}
else if (role == ServerState::ROLE_PRIMARY) {
TRI_json_t* json = TRI_CreateString2CopyJson(TRI_UNKNOWN_MEM_ZONE, "none", 4);
if (json == 0) {
locker.unlock();
LOG_FATAL_AND_EXIT("out of memory");
}
ServerState::instance()->setState(ServerState::STATE_SERVINGASYNC);
// register server
AgencyCommResult result = comm.setValue("Current/DBServers/" + _myId, json, 0.0);
TRI_FreeJson(TRI_UNKNOWN_MEM_ZONE, json);
if (! result.successful()) {
locker.unlock();
LOG_FATAL_AND_EXIT("unable to register db server in agency");
}
}
else if (role == ServerState::ROLE_SECONDARY) {
locker.unlock();
LOG_FATAL_AND_EXIT("secondary server tasks are currently not implemented");
}
}
return true;
}
bool ApplicationCluster::start () {
// set authentication data
ServerState::instance()->setAuthentication(_username, _password);
// overwrite memory area
_username = _password = "******";
ServerState::instance()->setDataPath(_dataPath);
ServerState::instance()->setLogPath(_logPath);
ServerState::instance()->setAgentPath(_agentPath);
ServerState::instance()->setArangodPath(_arangodPath);
ServerState::instance()->setDBserverConfig(_dbserverConfig);
ServerState::instance()->setCoordinatorConfig(_coordinatorConfig);
ServerState::instance()->setDisableDispatcherFrontend(_disableDispatcherFrontend);
ServerState::instance()->setDisableDispatcherKickstarter(_disableDispatcherKickstarter);
if (! enabled()) {
return true;
}
ServerState::instance()->setId(_myId);
// perfom an initial connect to the agency
const std::string endpoints = AgencyComm::getEndpointsString();
if (! AgencyComm::tryConnect()) {
LOG_FATAL_AND_EXIT("Could not connect to agency endpoints (%s)",
endpoints.c_str());
}
ServerState::RoleEnum role = ServerState::instance()->getRole();
if (role == ServerState::ROLE_UNDEFINED) {
// no role found
LOG_FATAL_AND_EXIT("unable to determine unambiguous role for server '%s'. No role configured in agency (%s)",
_myId.c_str(),
endpoints.c_str());
}
// check if my-address is set
if (_myAddress.empty()) {
// no address given, now ask the agency for out address
_myAddress = ServerState::instance()->getAddress();
}
else {
// register our own address
ServerState::instance()->setAddress(_myAddress);
}
if (_myAddress.empty()) {
LOG_FATAL_AND_EXIT("unable to determine internal address for server '%s'. "
"Please specify --cluster.my-address or configure the address for this server in the agency.",
_myId.c_str());
}
// now we can validate --cluster.my-address
const string unified = triagens::rest::Endpoint::getUnifiedForm(_myAddress);
if (unified.empty()) {
LOG_FATAL_AND_EXIT("invalid endpoint '%s' specified for --cluster.my-address",
_myAddress.c_str());
}
ServerState::instance()->setState(ServerState::STATE_STARTUP);
// initialise ConnectionManager library
httpclient::ConnectionManager::instance()->initialise();
// the agency about our state
AgencyComm comm;
comm.sendServerState(0.0);
const std::string version = comm.getVersion();
ServerState::instance()->setInitialised();
LOG_INFO("Cluster feature is turned on. "
"Agency version: %s, Agency endpoints: %s, "
"server id: '%s', internal address: %s, role: %s",
version.c_str(),
endpoints.c_str(),
_myId.c_str(),
_myAddress.c_str(),
ServerState::roleToString(role).c_str());
if (! _disableHeartbeat) {
AgencyCommResult result = comm.getValues("Sync/HeartbeatIntervalMs", false);
if (result.successful()) {
result.parse("", false);
std::map<std::string, AgencyCommResultEntry>::const_iterator it = result._values.begin();
if (it != result._values.end()) {
_heartbeatInterval = triagens::basics::JsonHelper::stringUInt64((*it).second._json);
LOG_INFO("using heartbeat interval value '%llu ms' from agency",
(unsigned long long) _heartbeatInterval);
}
}
// no value set in agency. use default
if (_heartbeatInterval == 0) {
_heartbeatInterval = 1000; // 1/s
LOG_WARNING("unable to read heartbeat interval from agency. Using default value '%llu ms'",
(unsigned long long) _heartbeatInterval);
}
// start heartbeat thread
_heartbeat = new HeartbeatThread(_server, _dispatcher, _applicationV8, _heartbeatInterval * 1000, 5);
if (_heartbeat == 0) {
LOG_FATAL_AND_EXIT("unable to start cluster heartbeat thread");
}
if (! _heartbeat->init() || ! _heartbeat->start()) {
LOG_FATAL_AND_EXIT("heartbeat could not connect to agency endpoints (%s)",
endpoints.c_str());
}
while (! _heartbeat->ready()) {
// wait until heartbeat is ready
usleep(10000);
}
}
return true;
}
