Chapter 1. Introduction to Performance Tuning
Limiting factors
Before considering how to improve performance, you need to consider what the limiting factors are. The main obstacles to a fast messaging system are, as follows:
- The speed at which messages are written to and read from disk (persistent brokers only).
- The speed at which messages can be marshalled and sent over the network.
- Context switching, due to multi-threading.
Ultimately, the tuning suggestions in this guide tackle the preceding limits in various ways.
Non-persistent and persistent brokers
The range of options for tuning non-persistent brokers are slightly different from the options for tuning persistent brokers. Most of the tuning techniques described in this chapter can be applied either to non-persistent or persistent brokers (with the exception of flow control, which is only relevant to non-persistent brokers).
Techniques specific to persistent brokers are discussed in Chapter 6, Persistent Messaging.
Broker networks
One of the major techniques for coping with large scale messaging systems is to establish a broker network, with brokers deployed on multiple hosts. This topic is discussed briefly in Section 2.7, “Horizontal Scaling”, but for a comprehensive discussion and explanation of how to set up a broker network, please consult Using Networks of Brokers.
