Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions (Addison-Wesley Signature Series (Fowler))

by Hohpe Gregor

Another potential downside of the publish-subscribe approach is that the pull model is more complex than the push model. As discussed earlier, the pull model requires more back-and-forth discussion than the push model. When the discussion is among distributed applications, the extra communication can significantly hurt performance.