These issues were found while I was testing the
neutron-dynamic-routing service in OpenStack, see
https://bugs.launchpad.net/neutron/+bug/1750383 and
https://bugs.launchpad.net/neutron/+bug/1750129
But using a modified version of the sample program shown at
http://ryu.readthedocs.io/en/latest/library_bgp_speaker.html I can
reproduce them with only ryu:
---<--->---<--->---snip---<--->---<--->---snap---<--->---<--->---
import eventlet
# BGPSpeaker needs sockets patched
eventlet.monkey_patch()
# initialize a log handler
# this is not strictly necessary but useful if you get messages like:
# No handlers could be found for logger "ryu.lib.hub"
import logging
import sys
log = logging.getLogger()
log.addHandler(logging.StreamHandler(sys.stderr))
from ryu.services.protocols.bgp.bgpspeaker import BGPSpeaker
def dump_remote_best_path_change(event):
print ('the best path changed:', event.remote_as, event.prefix,\
event.nexthop, event.is_withdraw)
def detect_peer_down(remote_ip, remote_as):
print ('Peer down:', remote_ip, remote_as)
if __name__ == "__main__":
speaker = BGPSpeaker(as_number=65001, router_id='10.0.0.1',
bgp_server_port=0,
best_path_change_handler=dump_remote_best_path_change,
peer_down_handler=detect_peer_down)
speaker.neighbor_add('10.42.0.4', 65001)
print ("BGP started")
count = 1
while True:
eventlet.sleep(10)
prefix = '10.20.' + str(count) + '.0/24'
print ("add a new prefix", prefix)
speaker.prefix_add(prefix)
count += 1
if count == 3:
break
# eventlet.sleep(10)
# print ("Remove neighbor")
# speaker.neighbor_del('10.42.0.4')
eventlet.sleep(10)
print ("Shutting down")
speaker.shutdown()
eventlet.sleep(300)
---<--->---<--->---snip---<--->---<--->---snap---<--->---<--->---
The result differs depending on whether there is actually a BGP peer
listening at the remote end, leading to the scenarios described in the
two bugs above. When the BGP session is connected at the time of the
shutdown, these tracebacks are being shown repeatedly:
hub: uncaught exception: Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/ryu/lib/hub.py", line
80, in _launch
return func(*args, **kwargs)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/utils/evtlet.py",
line 63, in __call__
self._funct(*self._args, **self._kwargs)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/speaker.py",
line 542, in _expired
self.send_notification(code, subcode)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/speaker.py",
line 374, in send_notification
self._send_with_lock(notification)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/speaker.py",
line 386, in _send_with_lock
self.connection_lost('failed to write to socket')
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/speaker.py",
line 596, in connection_lost
self._peer.connection_lost(reason)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/peer.py",
line 2328, in connection_lost
self._protocol.stop()
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/speaker.py",
line 405, in stop
Activity.stop(self)
File
"/usr/local/lib/python2.7/dist-packages/ryu/services/protocols/bgp/base.py",
line 314, in stop
raise ActivityException(desc='Cannot call stop when activity is '
ActivityException: 100.1 - Cannot call stop when activity is not
started or has been stopped already.
When the BGP session is not connected, there is no error, but using
tcpdump one can see connection attempts continuing after the shutdown.
As a workaround, removing all neighbors works, if I do that (currently
commented in the sample code), both issues disappear. I do think
however that ryu should be doing this automatically. Fixes welcome. ;)
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Ryu-devel mailing list
Ryu-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/ryu-devel
