This package contains the Solace PubSub+ Messaging API for Python.

The Solace PubSub+ Messaging API for Python is developed and supported by the Solace Corporation.

The API provides access to Solace PubSub+ Messaging Service, supporting a variety of Message Exchange Patterns.

Installation

Install the API using pip: pip install solace-pubsubplus

Dependencies

Solace PubSub+ Messaging API for Python requires Python 3.6 or greater.

Documentation

An online reference for the API is available at docs.solace.com.

Introduction

There are four primary objects in the PubSub+ Messaging API for Python that applications can use, which are as follows:

MessagingService

from solace.messaging.messaging_service import MessagingService The starting point for all client-broker connections. MessagingService defines and controls the connection to the Solace PubSub+ Event Broker.

A MessagingService object is created by the MessagingServiceBuilder.

MessagePublisher

from solace.messaging.publisher.message_publisher import MessagePublisher The abstract base class for a Message Publisher (MessagePublisher). Applications do not build MessagePublisher objects directly, rather an application will invoke a builder. for one of two derived objects:

1. DirectMessagePublisher: Created by a DirectMessagePublisherBuilder. DirectMessagePublisher send messages that are not acknowledged and are not stored on the Solace PubSub+ Event Broker. This is the fastest delivery path because messages are never queued and therefore cannot be delivered to offline MessageReceiver at a later time. Messages published by DirectMessagePublisher are eligible for discard when network congestion occurs.
2. PersistentMessagePublisher: Created by a PersistentMessagePublisherBuilder. PersistentMessagePublisher sends messages that are guaranteed to be delivered to MessageReceiver, even if the MessageReceiver object is offline. PubSub+ Event Broker stores the messages until they are delivered and consumed by all subscribing receivers.

MessageReceiver

from solace.messaging.receiver.message_receiver import MessageReceiver The abstract base class for a Message Receiver (Message Receiver). Applications do not build MessageReceiver objects directly, rather an application will invoke a builder for one of two derived objects:

1. DirectMessageReceiver: Created by a DirectMessageReceiverBuilder. DirectMessgeReceiver consumes messages as they are published. DirectMessageReceiver will not receive messages published before the receiver is created or while the receiver is offline. DirectMessageReceiver is not required to acknowledge received messages. DirectMessageReceiver may receive messages from any publisher (persistent or direct), but only while the DirectMessageReceiver is online.
2. PersistentMessageReceiver: Created by a PersistentMessageReceiverBuilder. PersistentMessageReceiver consume messages from a queue created on the Solace Pubsub+ Event broker. When the queue is created and subscriptions applied, it will begin storing messages, even if PersistentMessageReceiver is offline. Messages are stored until delivered to the PersistentMessageReceiver and the PersistentMessageReceiver acknowledges the message. PersistentMessageReceiver is responsible for acknowledging messages received to remove them from the PubSub+ Event Broker Queue.

Message

from solace.messaging.core.message import Message The abstract base class for a Message. Applications do not build a Message object directly, rather an application will invoke a builder for an OutboundMessage (for publish) or receive an InboundMessage (from a MessageReceiver).

Samples

Sample applications are available at the Solace Developer Community

multiprocessing

Solace PubSub+ Messaging API for Python cannot be used in applications that use the Python multiprocessing module.