def _publish_and_raises_on_missing_exchange(self, exchange, msg,
routing_key=None,
timeout=None):
"""Publisher that raises exception if exchange is missing."""
if not exchange.passive:
raise RuntimeError("_publish_and_retry_on_missing_exchange() must "
"be called with an passive exchange.")
try:
self._publish(exchange, msg, routing_key=routing_key,
timeout=timeout)
return
except self.connection.channel_errors as exc:
if exc.code == 404:
# NOTE(noelbk/sileht):
# If rabbit dies, the consumer can be disconnected before the
# publisher sends, and if the consumer hasn't declared the
# queue, the publisher's will send a message to an exchange
# that's not bound to a queue, and the message wll be lost.
# So we set passive=True to the publisher exchange and catch
# the 404 kombu ChannelError and retry until the exchange
# appears
raise rpc_amqp.AMQPDestinationNotFound(
"exchange %s doesn't exists" % exchange.name)
raise
def _publish_and_retry_on_missing_exchange(self,
exchange,
msg,
routing_key=None,
timeout=None):
"""Publisher that retry if the exchange is missing.
"""
if not exchange.passive:
raise RuntimeError("_publish_and_retry_on_missing_exchange() must "
"be called with an passive exchange.")
# TODO(sileht): use @retrying
# NOTE(sileht): no need to wait the application expect a response
# before timeout is exshauted
duration = (timeout
if timeout is not None else self.kombu_reconnect_timeout)
timer = rpc_common.DecayingTimer(duration=duration)
timer.start()
while True:
try:
self._publish(exchange,
msg,
routing_key=routing_key,
timeout=timeout)
return
except self.connection.channel_errors as exc:
# NOTE(noelbk/sileht):
# If rabbit dies, the consumer can be disconnected before the
# publisher sends, and if the consumer hasn't declared the
# queue, the publisher's will send a message to an exchange
# that's not bound to a queue, and the message wll be lost.
# So we set passive=True to the publisher exchange and catch
# the 404 kombu ChannelError and retry until the exchange
# appears
if exc.code == 404 and timer.check_return() > 0:
LOG.info(
_LI("The exchange %(exchange)s to send to "
"%(routing_key)s doesn't exist yet, "
"retrying...") % {
'exchange': exchange.name,
'routing_key': routing_key
})
time.sleep(0.25)
continue
elif exc.code == 404:
msg = _("The exchange %(exchange)s to send to "
"%(routing_key)s still doesn't exist after "
"%(duration)s sec abandoning...") % {
'duration': duration,
'exchange': exchange.name,
'routing_key': routing_key
}
LOG.info(msg)
raise rpc_amqp.AMQPDestinationNotFound(msg)
raise
