I'm trying to send messages to Azure Event Hub using python and the rest API after some failed experiments i have found working code (see below) but i want to be able to select to which partition to send the event.
Is this possible using the rest API and if so how should be done?
#!/user/bin/python
import json
from datetime import datetime
from multiprocessing import Pool
# from azure.servicebus import _service_bus_error_handler
from azure.servicebus.servicebusservice import ServiceBusService, ServiceBusSASAuthentication
from azure.http import (
HTTPRequest,
HTTPError
)
from azure.http.httpclient import _HTTPClient
EVENT_HUB_HOST = "mysecrethub.servicebus.windows.net"
EVENT_HUB_NAME = "secerthub-name"
KEYNAME = "senderkey" # needs to be loaded from ENV
KEYVALUE = "keyvalue" # needs to be loaded from ENV
EXTRA_HEADERS = []
NUM_OF_PARTITIONS = 16
class EventHubClient(object):
def __init__(self, host, hubname, keyname, keyvalue):
self._host = host
self._hub = hubname
self._keyname = keyname
self._key = keyvalue
def sendMessage(self, body, partition=None, additional_headers=None):
eventHubHost = self._host
httpclient = _HTTPClient(service_instance=self)
sasKeyName = self._keyname
sasKeyValue = self._key
authentication = ServiceBusSASAuthentication(sasKeyName, sasKeyValue)
request = HTTPRequest()
request.method = "POST"
request.host = eventHubHost
request.protocol_override = "https"
request.path = "/%s/messages?api-version=2014-01" % (self._hub)
request.body = body
request.headers.append(('Content-Type', 'application/atom+xml;type=entry;charset=utf-8'))
if additional_headers is not None:
for item in additional_headers:
request.headers.append(item)
if partition is not None:
value = json.dumps({'PartitionKey': partition})
request.headers.append(('BrokerProperties', value))
authentication.sign_request(request, httpclient)
request.headers.append(('Content-Length', str(len(request.body))))
status = 0
try:
resp = httpclient.perform_request(request)
status = resp.status
except HTTPError as ex:
status = ex.status
# print request.headers
return status
def prepare_message(appid, sessionid, partitionKey=None, SessionEllapsed=None, DeviceOs=None):
message = {"Name": "MonitorEvent"}
Attributes = {"AppId": appid, "SessionStarted": "".join(str(datetime.now())[:-3])}
if SessionEllapsed is not None:
Attributes['SessionEllapsed'] = SessionEllapsed
if DeviceOs is not None:
Attributes['DeviceOs'] = DeviceOs
if partitionKey is not None:
message["PartitionKey"] = str(partitionKey)
message["PartitionId"] = str(partitionKey)
Attributes['ItemId'] = partitionKey
message['Attributes'] = Attributes
return json.dumps(message)
def send_monitoring_event(partition):
hubClient = EventHubClient(EVENT_HUB_HOST, EVENT_HUB_NAME, KEYNAME, KEYVALUE)
appid = 1
sendertime = datetime.now().strftime('%Y%M%d-%H%M%S')
message = prepare_message(appid, sendertime, partitionKey=partition, SessionEllapsed=1, DeviceOs='Monitor' + str(partition))
# print message
hubStatus = hubClient.sendMessage(message, partition=None, additional_headers=EXTRA_HEADERS)
# return the HTTP status to the caller
return hubStatus
def main():
pool = Pool(processes=NUM_OF_PARTITIONS)
print pool.map(send_monitoring_event, range(NUM_OF_PARTITIONS))
if __name__ == '__main__':
main()
Following the section 'Send Event' of Event Hubs REST APIs docunment https://msdn.microsoft.com/en-us/library/azure/dn790664.aspx, you can't use the Request URI https://{serviceNamespace}.servicebus.windows.net/{eventHubPath}/messages to select to which partition to send events.
You should use the Request URI https://{serviceNamespace}.servicebus.windows.net/{eventHubPath}/publishers/{deviceId}/messages. The attribute {deviceId} is partition key what used to group/partition devices—whether it is geo-location, device type, version, tenant, and so on.
But the partition count must be a number between 2 and 32. So if you need to use more than 32 partitions, I suggest to put the key into the event data.
Best Regards.