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);
}
}
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;
}