MartinFowler.com said: “The term “Microservice Architecture” has sprung up over the last few years to describe a particular way of designing software applications as suites of independently deployable services.” See the full article here.
The Java Application API allows streaming applications to be written in Java for IBM Streams. Tuples on a stream can be any Java object that is serializable. A stream, represented by the interface TStream, is processed using a functional programming style, when a function transforms the stream by being called on each tuple, and the returned value drives the contents of the new stream.
In the first article in this series I explained tumbling windows, for example, a tumbling window allows you to calculate the average price of a stock symbol over the last five minutes, every five minutes (eviction policy time(300.0)). If there was some rapid movement in the price, a tumbling window would not report it until the next eviction, which could be up to five minutes, too late to make a trade decision. This is where sliding windows are useful, a sliding window of tuples is continuously maintained, such as the last five minutes of stock prices, and then the average price over the window can be continuously maintained. So a change in the average price can be seen as soon as the event occurs that drive the change.
SPL supports the concept of windows, the ability to perform some processing on a window of data. A stream is an infinite sequence of data (as tuples), so to perform certain operations, a subset of the data must be used. For example, calculating the maximum value of or sorting an infinite stream would have to wait an infinite amount of time to see all the data. SPL provides the ability to process subsets of streams though windows.
This article outlines a technique for supporting redundant flows that only generate a single external effect. The technique is described in terms of an application that generates alerts using text messages (SMS) with a theoretical SMSSink operator, though it can be applied to any sink operator.