Axis 2 Engine Wiki   Wish List  Sub components    1. Handler
frame work and Message Invocation .   2. Engine Registry (Engine
Configuration).   3. Phased Handler resolver .   4.
Management/Admin API.   5. Providers and transport senders.   6.
Sync and Async Message flows.  Execution, Concepts  The Exaction
Model or the Engine in Axis terminology, addresses how the
components of Apache Axis2 are executed or how control is passed
from one component to another. The Axis Execution Model does not
assume any specific Message Exchange Patterns or synchronous,
Asynchronous behavior in its execution.  The Axis Engine is
built on top of two flows, they are called in-flow and out-flow
respectively (in addition to that there is a flow called fault
flow which is used when the engine gets processing errors). Each
flow encompasses a set of components, namely Handlers,
Transport Senders, Transport Receivers, Receivers,
Senders and Providers.   The Handlers are the extension
mechanism for Axis and represents