def send_json_rpc(cmd, args, hosts, timeout=0.5):
rv = {}
context = zmq.Context()
if isinstance(hosts, basestring):
hosts = [hosts]
for host in hosts:
rv[host] = None
try:
request = context.socket(zmq.DEALER)
request.connect('tcp://%s:5000' % host)
request.setsockopt(zmq.LINGER, 0)
#request.send_multipart([msgpack.packb(cmd), msgpack.packb(args)])
request.send(msgpack.packb([cmd, args]))
poller = zmq.Poller()
poller.register(request, zmq.POLLIN)
start = time()
while True:
socks = dict(poller.poll(timeout=timeout / 10.))
if request in socks and socks[request] == zmq.POLLIN:
rv[host] = msgpack.unpackb(request.recv(zmq.POLLERR))
break
if (time() - start) > timeout:
break
sleep(timeout / 10.)
except zmq.ZMQError as err:
print str(err)
continue
return rv
def _send_request(req_id, action, key, value=None):
""" Generate a request ID, push the request to the node and wait for the
result, filtering by the ID on the subscription.
This should be a request/response call to the node, but since many must be
possible at the same time, a PUSH/PULL AND PUB/SUB with an unique ID for
each request is used instead.
:return: the node response
:rtype: []
"""
# Create and connect the sockets.
context = current_app.config["context"]
subscriber = context.socket(SUB)
subscriber.setsockopt_string(SUBSCRIBE, req_id)
subscriber.connect(SUB_ENDPOINT)
request = context.socket(PUSH)
request.setsockopt(SNDTIMEO, _TIMEOUT)
request.connect(PUSH_ENDPOINT)
# Push the request.
request.send_json([req_id, action, key, value])
# Wait for the response from the publisher.
poller = Poller()
poller.register(subscriber, POLLIN)
sockets = dict(poller.poll(_TIMEOUT))
if subscriber not in sockets: # no response, time out
raise InternalServerError()
# Return the response, without the unique request ID
return subscriber.recv_multipart()[1:]
