SOA-Reliability (SOA-Rity) for HTTP
Yaron Y. Goland · 2005
SOAR-ity is intended to allow for reliable (this term is almost always a misnomer) messaging over HTTP. It achieves this goal by introducing two new request headers, Message-ID which provides a unique ID for a message and MsgCreate which contains the date and time on which the first instance of the message with the associated Message-ID was sent. The purpose of the Message-ID/MsgCreate pair is to allow any HTTP request (e.g. any HTTP method can be used) to be repeated multiple times with a guarantee that the message will be processed no more than one time. In essence it makes any HTTP method call idempotent.