![]() Although it might be only a millisecond or less for each individual call, it quickly gets compounded by the sheer number of calls. I have used a web page example in order to illustrate the effect of extremely high latencies on performance, but the situation is quite similar in low-latency environments as well.Įach database query, each call to a remote service, and each Coherence cache access will incur some latency. You must be wondering by now whether you are reading a book about website performance optimization and what all of this has to do with Coherence. Each image, external CSS style sheet, or JavaScript file that your page references, will add latency and turn your sub-second response time into 5 seconds or more. Even the extremely simple Google front page requires four HTTP requests, and most non-trivial pages require 15 to 20, or even more. ![]() Unfortunately, it is highly unlikely that one request will be enough. On the other hand, even if your page takes 700 milliseconds to render and your server is in Sydney, your users in Florida could still have a sub-second response time, as long as they are able to retrieve the page in a single request. For example, on my development box, retrieval of a single row from the MySQL database using EclipseLink and rendering of the retrieved object using FreeMarker template takes 18 milliseconds on an average, according to the YourKit Profiler. However, I have intentionally chosen 20 milliseconds for this example, because many operations that web applications typically perform complete in 20 milliseconds or less. Of course, as the execution time of the operation itself increases, latency as a percentage of the total time will decrease. When the server is half way around the globe, it is the latency that pretty much determines how long an operation will take. However, as soon as you move the server out of the building it becomes significant. Towards the end, you learn how to integrate Coherence with different persistence technologies, how to access Coherence from platforms other than Java, and how to test and debug classes and applications that depend on Coherence.Īs you can see from the previous table, the impact of latency is minimal on the local host, or even when accessing another host on the same network. It contains a collection of best practice-based solutions and mini-frameworks that will allow you to be more productive from the very beginning.The early chapters cover basics like installation guidelines and caching topologies, before moving on to the domain model implementation guidelines, distributed queries and aggregations, parallel processing, and real-time events. Based on the authors' extensive knowledge of Oracle Coherence, and how to use it in the real world, this book will provide you with all the information you need in order to leverage various Coherence features properly. Oracle Coherence provides a solid architectural foundation for scalable, high-performance and highly available enterprise applications, through features such as distributed caching, parallel processing, distributed queries and aggregations, real-time events, and the elimination of single points of failure.However, in order to take full advantage of these features, you need to design your application for Coherence from the beginning. ![]() You will learn when and how to use Coherence features such as distributed caching, parallel processing, and real-time events within your application, and understand how Coherence fits into the overall application architecture. ![]() ![]() This indispensible book will teach you how to achieve these things using Oracle Coherence, a leading data grid product on the market.Authored by leading Oracle Coherence authorities, this essential book will teach you how to use Oracle Coherence to build high-performance applications that scale to hundreds of machines and have no single points of failure. Scalability, performance, and reliability have to be designed into an application from the very beginning, as there may be substantial cost or implementation consequences if they need to be added down the line. ![]()
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