Book Image

Getting Started with Oracle Event Processing 11g

Book Image

Getting Started with Oracle Event Processing 11g

Overview of this book

Events are everywhere, events which can have positive or negative impacts on our lives and important business decisions. These events can impact a company's success, failure, and profitability. Technology now allows people from all walks of life to create Event Driven applications that will immediately and completely respond to the events that affect you and your business. So you are much more responsive to your customers, and competitive threats, and can take advantage of transient time sensitive situations. "Getting Started with Oracle Event Processing" will let you benefit from the skills and years of experience from the original pioneers who were the driving force behind this immensely flexible, complete, and award winning Event Stream Processing technology. It provides all of the information needed to rapidly deliver and understand Event Driven Architecture (EDA) Applications. These can then be executed on the comprehensive and powerful integral Java Event Server platform which utilizes the hardware and operating system.After an introduction into the benefits and uses of Event Stream Processing, this book uses tutorials and practical examples to teach you how to create valuable and rewarding Event Driven foundational applications. First you will learn how to solve Event Stream Processing problems, followed by the fundamentals of building an Oracle Event processing application in a step by step fashion. Exciting and unique topics are then covered: application construction, the powerful capabilities of the Oracle Event Processing language, CQL, monitoring and managing these applications, and the fascinating domain of real-time Geospatial Movement Analysis. Getting Started with Oracle Event Processing will provide a unique perspective on product creation, evolution and a solid understanding on how to effectively use the product.
Table of Contents (19 chapters)
Getting Started with Oracle Event Processing 11g
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

The EventPartitioner example


While the use of an EventPartitioner has been superseded to some extent with the newer capabilities in Oracle Event Processing for enabling concurrency in a single event processor instance, it is still worthwhile mentioning this important capability.

Typically, you can partition events onto threads upstream to the channel, and in the following example, we have two threads each carrying a subset of the input "stock symbols". In this particular case, the channel partitions the input events by hashing the specified property "symbol". This means that events containing the same value for symbol will be partitioned always to the same processor. The hash function used is one that minimizes the number of collisions. The result of the hash is then divided by the number of listeners and the remainder used to select the proper listener. This can effectively reduce lock contention in the processors because each one will get fewer events, and there is no lock shared across...