Beispiel #1
0
void AgencyCallback::refetchAndUpdate(bool needToAcquireMutex) {
  if (!_needsValue) {
    // no need to pass any value to the callback
    if (needToAcquireMutex) {
      CONDITION_LOCKER(locker, _cv);
      executeEmpty();
    } else {
      executeEmpty();
    }
    return;
  }

  AgencyCommResult result = _agency.getValues(key);

  if (!result.successful()) {
    return;
  }
  
  std::vector<std::string> kv = basics::StringUtils::split(AgencyComm::prefixPath() + key,'/');
  kv.erase(std::remove(kv.begin(), kv.end(), ""), kv.end());
  
  std::shared_ptr<VPackBuilder> newData = std::make_shared<VPackBuilder>();
  newData->add(result.slice()[0].get(kv));
  
  if (needToAcquireMutex) {
    CONDITION_LOCKER(locker, _cv);
    checkValue(newData);
  } else {
    checkValue(newData);
  }
}
Beispiel #2
0
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);
  }
}
Beispiel #3
0
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);
  }
}