Traffic Monitor源码分析

从simple_switch_13.SimpleSwitch13控制器继承并开发

class SimpleMonitor13(simple_switch_13.SimpleSwitch13):

增添datapaths列表,存储交换机id

def __init__(self, *args, **kwargs):
super(SimpleMonitor13, self).__init__(*args, **kwargs)
self.datapaths = {}

引入hub.spawn()函数启动一个新线程,输入为一个新的方法_monitor

创建一个EventOFPStateChange监听事件,监听MAIN_DISPATCHER,DEAD_DISPATCHER两种情况。

@set_ev_cls(ofp_event.EventOFPStateChange,
[MAIN_DISPATCHER, DEAD_DISPATCHER])

监听如果为MAIN_DISPATCHER,并且datapath.id不在datapath列表中,则证明是新加入的交换机

if ev.state == MAIN_DISPATCHER:
if datapath.id not in self.datapaths:
self.logger.debug('register datapath: %016x', datapath.id)
self.datapaths[datapath.id] = datapath

如果为DEAD_DISPATCHER,并且datapath.id在datapath列表中,则证明是掉线的交换机

 elif ev.state == DEAD_DISPATCHER:
if datapath.id in self.datapaths:
self.logger.debug('unregister datapath: %016x', datapath.id)
del self.datapaths[datapath.id]

_monitor方法,循环不断向datapath列表中的交换机发送Flow状态请求,和Port状态请求

def _monitor(self):
while True:
for dp in self.datapaths.values():
self._request_stats(dp)
hub.sleep(10)
def _request_stats(self, datapath):
self.logger.debug('send stats request: %016x', datapath.id)
ofproto = datapath.ofproto
parser = datapath.ofproto_parser req = parser.OFPFlowStatsRequest(datapath)
datapath.send_msg(req) req = parser.OFPPortStatsRequest(datapath, 0, ofproto.OFPP_ANY)
datapath.send_msg(req)

刚刚发送了请求,现在监听其回复

@set_ev_cls(ofp_event.EventOFPFlowStatsReply, MAIN_DISPATCHER)
... @set_ev_cls(ofp_event.EventOFPPortStatsReply, MAIN_DISPATCHER)
...

打印返回的信息

for stat in sorted([flow for flow in body if flow.priority == 1],
key=lambda flow: (flow.match['in_port'],
flow.match['eth_dst'])):
self.logger.info('%016x %8x %17s %8x %8d %8d',
ev.msg.datapath.id,
stat.match['in_port'], stat.match['eth_dst'],
stat.instructions[0].actions[0].port,
stat.packet_count, stat.byte_count) ...
for stat in sorted(body, key=attrgetter('port_no')):
self.logger.info('%016x %8x %8d %8d %8d %8d %8d %8d',
ev.msg.datapath.id, stat.port_no,
stat.rx_packets, stat.rx_bytes, stat.rx_errors,
stat.tx_packets, stat.tx_bytes, stat.tx_errors)

其中sorted ... lambda语法,指元组的排列顺序按照先in_porteth_dst

至此,整个程序解析完毕。

04-13 18:44