Polling Consumer - Enterprise Integration Patterns

Messaging Patterns

Polling Consumer

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An application needs to consume Messages, but it wants to control when it consumes each message.

How can an application consume a message when the application is ready?

The application should use a Polling Consumer, one that explicitly makes a call when it wants to receive a message.

This is also known as a synchronous receiver, because the receiver thread blocks until a message is received. We call it a Polling Consumer because the receiver polls for a message, processes it, then polls for another. As a convenience, messaging API’s usually provide a receive method that blocks until a message is delivered, in addition to methods like receiveNoWait() and Receive(0) that return immediately if no message is available. This difference is only apparent when the receiver is polling faster than messages are arriving.

... Read the entire pattern in the book Enterprise Integration Patterns

Integration Pattern Language

Correlation Identifier

Composed Msg. Processor

Message
Transformation

Event-driven Consumer

Point-to-Point Channel

Publish-Subscr. Channel

Datatype Channel

Invalid Message Channel

Integration Styles
Table of Contents
Preface
Introduction
Solving Integration Problems using Patterns
File Transfer
Shared Database
Remote Procedure Invocation
Messaging
Messaging Systems
Message Channel
Message
Pipes and Filters
Message Router
Message Translator
Message Endpoint
Messaging Channels
Point-to-Point Channel
Publish-Subscribe Channel
Datatype Channel
Invalid Message Channel
Dead Letter Channel
Guaranteed Delivery
Channel Adapter
Messaging Bridge
Message Bus
Message Construction
Command Message
Document Message
Event Message
Request-Reply
Return Address
Correlation Identifier
Message Sequence
Message Expiration
Format Indicator
Interlude: Simple Messaging
JMS Request/Reply Example
.NET Request/Reply Example
JMS Publish/Subscribe Example
Message Routing
Content-Based Router
Message Filter
Dynamic Router
Recipient List
Splitter
Aggregator
Resequencer
Composed Msg. Processor
Scatter-Gather
Routing Slip
Process Manager
Message Broker
Message Transformation
Envelope Wrapper
Content Enricher
Content Filter
Claim Check
Normalizer
Canonical Data Model
Interlude: Composed Messaging
Synchronous (Web Services)
Asynchronous (MSMQ)
Asynchronous (TIBCO)
Messaging Endpoints
Messaging Gateway
Messaging Mapper
Transactional Client
Polling Consumer
Event-Driven Consumer
Competing Consumers
Message Dispatcher
Selective Consumer
Durable Subscriber
Idempotent Receiver
Service Activator
System Management
Control Bus
Detour
Wire Tap
Message History
Message Store
Smart Proxy
Test Message
Channel Purger
Interlude: Systems Management Example
Instrumenting Loan Broker
Integration Patterns in Practice
Case Study: Bond Trading System
Concluding Remarks
Emerging Standards
Appendices
Bibliography
Revision History

You can reuse the following elements under the Creative Commons Attribution license: pattern icon, pattern name, problem and solution statements (in bold), and the sketch. Other portions are protected by copyright.

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