Manage queues - Message Service - Alibaba Cloud Documentation Center

Step 1: Prepare the environment

Download the latest version of the SDK for Python, decompress the package, and then go to the mns_python_sdk subdirectory.
Open the sample.cfg file, and specify the AccessKey ID, AccessKey secret, and endpoint.
- AccessKey ID and AccessKey secret
  - The AccessKey pair that is used to call API operations in Alibaba Cloud.
  - If you are using an Alibaba Cloud account, go to the AccessKey Management page of the Alibaba Cloud Management Console to create and view your AccessKey pair.
  - If you are a Resource Access Management (RAM) user, log on to the RAM console to view your AccessKey pair.
- Endpoint
  - The endpoint that is used to access Message Service (MNS). To view the endpoints of MNS, log on to the MNS console. For more information, see View the endpoints of a queue.
  - The endpoints of MNS vary based on regions.
- SecurityToken
  - The temporary access credential that is provided by RAM. If you use an Alibaba Cloud account or a RAM user identity to access Alibaba Cloud services, you do not need to specify a Security Token Service (STS) token. For more information, see What is STS?.
Go to the sample directory where all the sample code resides.

Step 2: Create a queue

Run the createqueue.py file to create a queue. The default name of the new queue is MySampleQueue. You can also specify another queue name. For more information, see Queue.

Run the following command:

python createqueue.py MyQueue1

The following result is returned:

Create Queue Succeed! QueueName:MyQueue1

Sample code:

The endpoint, AccessKey ID, AccessKey secret, and STS token are retrieved from the sample.cfg file that is specified in Step 1.

my_account = Account(endpoint, accid, acckey, token)
queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
my_queue = my_account.get_queue(queue_name)

queue_meta = QueueMeta()
try:
    queue_url = my_queue.create(queue_meta)
    print "Create Queue Succeed! QueueName:%s\n" % queue_name
except MNSExceptionBase, e:
    if e.type == "QueueAlreadyExist":
        print "Queue already exist, please delete it before creating or use it directly."
        sys.exit(0)
    print "Create Queue Fail! Exception:%s\n" % e

Step 3: Send messages

Run the sendmessage.py file to send multiple messages to the queue. You must use the queue name that is specified in Step 2. For more information, see QueueMessage.

Run the following command:

python sendmessage.py MyQueue1

The following result is returned:

==========Send Message To Queue==========
QueueName:MyQueue1
MessageCount:3

Send Message Succeed! MessageBody:I am test message 0. MessageID:3EBE662B52BC99BC-1-154BD99CCA7-200000001
Send Message Succeed! MessageBody:I am test message 1. MessageID:64B92941FC57837F-2-154BD99CCCE-200000001
Send Message Succeed! MessageBody:I am test message 2. MessageID:3EBE662B52BC99BC-1-154BD99CCF0-200000002

Sample code:

The endpoint, AccessKey ID, AccessKey secret, and STS token are retrieved from the sample.cfg file that is specified in Step 1.

my_account = Account(endpoint, accid, acckey, token)
queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
my_queue = my_account.get_queue(queue_name)

msg_count = 3

print "%sSend Message To Queue%s\nQueueName:%s\nMessageCount:%s\n" % (10*"=", 10*"=", queue_name, msg_count)
for i in range(msg_count):
    try:
        msg_body = "I am test message %s." % i
        msg = Message(msg_body)
        re_msg = my_queue.send_message(msg)
        print "Send Message Succeed! MessageBody:%s MessageID:%s" % (msg_body, re_msg.message_id)
    except MNSExceptionBase, e:
        if e.type == "QueueNotExist":
            print "Queue not exist, please create queue before send message."
            sys.exit(0)
        print "Send Message Fail! Exception:%s\n" % e

Step 4: Receive and delete the messages

Run the recvdelmessage.py file to receive and delete all the messages from the queue. You must use the queue name that is specified in Step 2. MNS returns a response for a long-polling request only if a message is available in the queue or the request times out. If you set the value of the WaitSeconds parameter to 3, the long-polling request times out after three seconds. For more information, see QueueMessage.

Run the following command:

python recvdelmessage.py MyQueue1

The following result is returned:

==========Receive And Delete Message From Queue==========
QueueName:MyQueue1
WaitSeconds:3

Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTEtOA== MessageBody:I am test message 0. MessageID:3EBE662B52BC99BC-1-154BD99CCA7-200000001
Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTEtOA==
Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5NC0xNDYzNDcwNDU4LTEtOA== MessageBody:I am test message 2. MessageID:3EBE662B52BC99BC-1-154BD99CCF0-200000002
Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5NC0xNDYzNDcwNDU4LTEtOA==
Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTItOA== MessageBody:I am test message 1. MessageID:64B92941FC57837F-2-154BD99CCCE-200000001
Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTItOA==
Queue is empty!

Sample code:

The endpoint, AccessKey ID, AccessKey secret, and STS token are retrieved from the sample.cfg file that is specified in Step 1.

my_account = Account(endpoint, accid, acckey, token)
queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
my_queue = my_account.get_queue(queue_name)

wait_seconds = 3
print "%sReceive And Delete Message From Queue%s\nQueueName:%s\nWaitSeconds:%s\n" % (10*"=", 10*"=", queue_name, wait_seconds)
while True:
    try:
        recv_msg = my_queue.receive_message(wait_seconds)
        print "Receive Message Succeed! ReceiptHandle:%s MessageBody:%s MessageID:%s" % (recv_msg.receipt_handle, recv_msg.message_body, recv_msg.message_id)
    except MNSExceptionBase,e:
        if e.type == "QueueNotExist":
            print "Queue not exist, please create queue before receive message."
            sys.exit(0)
        elif e.type == "MessageNotExist":
            print "Queue is empty!"
            sys.exit(0)
        print "Receive Message Fail! Exception:%s\n" % e
        continue

    try:
        my_queue.delete_message(recv_msg.receipt_handle)
        print "Delete Message Succeed!  ReceiptHandle:%s" % recv_msg.receipt_handle
    except MNSException,e:
        print "Delete Message Fail! Exception:%s\n" % e

Step 5: Delete the queue

Run the deletequeue.py file to delete the queue.

Run the following command:

python deletequeue.py MyQueue1

The following result is returned:

Delete Queue Succeed! QueueName:MyQueue1

Sample code:

The endpoint, AccessKey ID, AccessKey secret, and STS token are retrieved from the sample.cfg file that is specified in Step 1.

my_account = Account(endpoint, accid, acckey, token)
queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
my_queue = my_account.get_queue(queue_name)

try:
    my_queue.delete()
    print "Delete Queue Succeed! QueueName:%s\n" % queue_name
except MNSExceptionBase, e:
    print "Delete Queue Fail! Exception:%s\n" % e