// Some users are connected for weeks and they are blocking backend to be destroyed and its memory

	// to be freed. We are finding users who are inactive for more than "idle_reconnect_time" seconds and

	// reconnect them to long-running backend, where they can idle hapilly till the end of ages.

	time_t now = time(NULL);

	std::vector<User *> usersToMove;

	unsigned long diff = CONFIG_INT(m_config, "service.idle_reconnect_time");

	if (diff != 0) {

		for (std::list<Backend *>::const_iterator it = m_clients.begin(); it != m_clients.end(); it++) {

			// Users from long-running backends can't be moved

			if ((*it)->longRun) {

				continue;

			}

			// Find users which are inactive for more than 'diff'

			BOOST_FOREACH(User *u, (*it)->users) {

				if (now - u->getLastActivity() > diff) {

					usersToMove.push_back(u);

				}

			}

		}

		// Move inactive users to long-running backend.

		BOOST_FOREACH(User *u, usersToMove) {

			LOG4CXX_INFO(logger, "Moving user " << u->getJID().toString() << " to long-running backend");

			if (!moveToLongRunBackend(u))

				break;

		}

	}

	// We have to remove startingBackend flag otherwise 1 broken backend start could

	// block the backend.

	m_startingBackend = false;

	// check ping responses

	std::vector<Backend *> toRemove;

	for (std::list<Backend *>::const_iterator it = m_clients.begin(); it != m_clients.end(); it++) {

		// pong has been received OR backend just connected and did not have time to answer the ping

		// request.

		if ((*it)->pongReceived || (*it)->pongReceived == -1) {

			// Don't send another ping if pongReceived == -1, because we've already sent one

			// when registering backend.

			if ((*it)->pongReceived) {

				sendPing((*it));

			}

		}

		else {

			LOG4CXX_INFO(logger, "Disconnecting backend " << (*it) << " (ID=" << (*it)->id << "). PING response not received.");

			toRemove.push_back(*it);

		}

		if ((*it)->users.size() == 0) {

			LOG4CXX_INFO(logger, "Disconnecting backend " << (*it) << " (ID=" << (*it)->id << "). There are no users.");

			toRemove.push_back(*it);

		}

	}

	BOOST_FOREACH(Backend *b, toRemove) {

		handleSessionFinished(b);

	}

	m_pingTimer->start();

}

void NetworkPluginServer::collectBackend() {

	// Stop accepting new users to backend with the biggest memory usage. This prevents backends

	// which are leaking to eat whole memory by connectin new users to legacy network.

	LOG4CXX_INFO(logger, "Collect backend called, finding backend which will be set to die");

	unsigned long max = 0;

	Backend *backend = NULL;

	for (std::list<Backend *>::const_iterator it = m_clients.begin(); it != m_clients.end(); it++) {

		if ((*it)->res > max) {

			max = (*it)->res;

			backend = (*it);

		}

	}

	if (backend) {

		if (m_collectTimer) {

			m_collectTimer->start();

		}

		LOG4CXX_INFO(logger, "Backend " << backend << " (ID=" << backend->id << ") is set to die");

		backend->acceptUsers = false;

	}

}

bool NetworkPluginServer::moveToLongRunBackend(User *user) {

	// Check if user has already some backend

	Backend *old = (Backend *) user->getData();

	if (!old) {

		LOG4CXX_INFO(logger, "User " << user->getJID().toString() << " does not have old backend. Not moving.");

		return true;

	}

	// if he's already on long run, do nothing

	if (old->longRun) {

		LOG4CXX_INFO(logger, "User " << user->getJID().toString() << " is already on long-running backend. Not moving.");