Messaging pattern: Difference between revisions
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==ØMQ== |
==ØMQ== |
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The [[ØMQ]] message queueing library provides |
The [[ØMQ]] message queueing library provides so-called ''sockets'' (a kind of generalization over the traditional [[Internet socket|IP]] and [[Unix domain socket|Unix sockets]]) which require indicating a messaging pattern to be used, and are optimized for each pattern. The basic ØMQ patterns are:<ref>[http://www.zeromq.org/docs:user-guide ØMQ User Guide]</ref> |
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*'''[[Request–response|Request–reply]]''' connects a set of clients to a set of services. This is a [[remote procedure call]] and task distribution pattern.{{clarify|date=November 2010}} |
*'''[[Request–response|Request–reply]]''' connects a set of clients to a set of services. This is a [[remote procedure call]] and task distribution pattern.{{clarify|date=November 2010}} |
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*'''[[Publish–subscribe pattern|Publish–subscribe]]''' connects a set of publishers to a set of subscribers. This is a data distribution pattern.{{clarify|date=November 2010}} |
*'''[[Publish–subscribe pattern|Publish–subscribe]]''' connects a set of publishers to a set of subscribers. This is a data distribution pattern.{{clarify|date=November 2010}} |
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Revision as of 19:40, 29 October 2015
In software architecture, a messaging pattern is a network-oriented architectural pattern which describes how two different parts of a message passing system connect and communicate with each other.
In telecommunications, a message exchange pattern (MEP) describes the pattern of messages required by a communications protocol to establish or use a communication channel. There are two major message exchange patterns — a request–response pattern, and a one-way pattern. For example, HTTP is a request–response pattern protocol, and UDP is a one-way pattern.[1]
SOAP
The term "Message Exchange Pattern" has a specific meaning within the Simple Object Access protocol (SOAP).[2][3] SOAP MEP types include:
- In-Only: This is equivalent to one-way. A standard one-way messaging exchange where the consumer sends a message to the provider that provides only a status response.
- Robust In-Only: This pattern is for reliable one-way message exchanges. The consumer initiates with a message to which the provider responds with status. If the response is a status, the exchange is complete, but if the response is a fault, the consumer must respond with a status.
- In-Out: This is equivalent to request–response. A standard two-way message exchange where the consumer initiates with a message, the provider responds with a message or fault and the consumer responds with a status.
- In Optional-Out: A standard two-way message exchange where the provider's response is optional.
- Out-Only: The reverse of In-Only. It primarily supports event notification. It cannot trigger a fault message.
- Robust Out-Only: similar to the out-only pattern, except it can trigger a fault message. The outbound message initiates the transmission.
- Out-In: The reverse of In-Out. The provider transmits the request and initiates the exchange.
- Out-Optional-In: The reverse of In-Optional-Out. The service produces an outbound message. The incoming message is optional ("Optional-in").
ØMQ
The ØMQ message queueing library provides so-called sockets (a kind of generalization over the traditional IP and Unix sockets) which require indicating a messaging pattern to be used, and are optimized for each pattern. The basic ØMQ patterns are:[4]
- Request–reply connects a set of clients to a set of services. This is a remote procedure call and task distribution pattern.[clarification needed]
- Publish–subscribe connects a set of publishers to a set of subscribers. This is a data distribution pattern.[clarification needed]
- Push–pull connects nodes in a fan-out / fan-in pattern that can have multiple steps, and loops. This is a parallel task distribution and collection pattern.[clarification needed]
- Exclusive pair connects two sockets in an exclusive pair. This is a low-level pattern for specific, advanced use cases.
Each pattern defines a particular network topology. Request-reply defines so-called "service bus", publish-subscribe defines "data distribution tree", push-pull defines "parallelised pipeline". All the patterns are deliberately designed in such a way as to be infinitely scalable and thus usable on Internet scale.[5]
See also
References
- ^ Erl, Thomas (2005). Service Oriented Architecture: Concepts, Technology, and Design. Indiana: Pearson Education. p. 171. ISBN 0-13-185858-0.
- ^ http://www.w3.org/TR/soap12-part1/#soapmep SOAP MEPs in SOAP W3C Recommendation v1.2
- ^ Web Services Description Language (WSDL) Version 2.0: Additional MEPs
- ^ ØMQ User Guide
- ^ Scalability Layer Hits the Internet Stack