rabbitmq-python-pika

Publisher and Consumer implementations for RabbitMQ using Python Pika

Connection Types

Asynchronous Connection:

• Does not require an response from server that message has been received before sending another, or moving on to another task.

Blocking Connection:

• Requires an response from server that message has been received after making every request.

Exchange Types

Fanout Exchange:

• Publish/Subscribe pattern -> send messages to all consumers
• Queues are automatically created when a consumer connects, and bound to the Fanout Exchange
• Published messages are broadcasted to all queues bound to the specific Fanout Exchange
• Consumers get messages that are published only after they have connected to the RabbitMQ Server
• No routing keys

Direct Exchange:

• A message goes to the queues whose binding key exactly matches the routing key in the message
• Only consumers that connect to that particular queue will receive the message
• Can route same message to more than one queue, because queue is explicitly bound with exchange

Topic Exchange:

• Similar to Direct Exchange, however compares routing key with binding pattern, instead of binding key
• Patterns:
  1. * -> one or more occurrence of word
  2. # -> zero or more occurrence of word

Install and Setup RabbitMQ on localhost

Install on Mac OSX:

$ brew install rabbitmq

Export RabbitMQ to PATH:

$ export PATH=$PATH:/user/local/sbin

Start RabbitMQ Management GUI:

$ rabbitmq-plugins enable rabbitmq-management

• URL: http://localhost:15672
• Default Credentials:
  • Username: guest
  • Password: guest

RabbitMQ Config File: [

    {rabbit,
        [
        {tcp_listeners, [{"127.0.0.1", 5672},
                        {"::1", 5672}]},
        {num_tcp_acceptors, 100},
        ]
    }
    
].

• Location: /usr/local/etc/rabbitmq/rabbitmq.conf

Start RabbitMQ Server:

$ brew services start rabbitmq

Stop RabbitMQ Server:

$ brew services stop rabbitmq

Install Pika

Install Dependencies (in same folder as Pipfile):

$ pipenv install 

Run:

Example:

$ python blocking_communication_publisher.py