@Override public ExternalFirewallDeviceVO findSuitableFirewallForNetwork(Network network) throws InsufficientCapacityException { long physicalNetworkId = network.getPhysicalNetworkId(); List<ExternalFirewallDeviceVO> fwDevices = _externalFirewallDeviceDao.listByPhysicalNetwork(physicalNetworkId); // loop through the firewall device in the physical network and pick the first-fit for (ExternalFirewallDeviceVO fwDevice : fwDevices) { // max number of guest networks that can be mapped to this device long fullCapacity = fwDevice.getCapacity(); if (fullCapacity == 0) { fullCapacity = _defaultFwCapacity; // if capacity not configured then use the default } // get the list of guest networks that are mapped to this load balancer List<NetworkExternalFirewallVO> mappedNetworks = _networkExternalFirewallDao.listByFirewallDeviceId(fwDevice.getId()); long usedCapacity = (mappedNetworks == null) ? 0 : mappedNetworks.size(); if ((fullCapacity - usedCapacity) > 0) { return fwDevice; } } throw new InsufficientNetworkCapacityException("Unable to find a firewall provider with sufficient capcity " + " to implement the network", DataCenter.class, network.getDataCenterId()); }