On Windows
This post explores what the term Window means. Wikipedia under the topic of Data Stream Management System lists a nice definition of Window: Instead of using synopses to compress the characteristics of...
View ArticleClik here to view.
Architecture Diagram
This diagram organizes the various components that are needed to fulfill event and time analysis requirements. The diagram displays the components in levels. The positioning of a component helps...
View ArticleClik here to view.
6+ Million Events-Per-Second
There is a big change and a smaller targeted change in release 7 for increasing performance. In my test release 7 hits 6.29 million of events per second on a decent CPU. The big change is that release...
View ArticleOn Lateness, Event Time vs. Processing Time and Watermarks, Order-Of-Arrival,...
EPL is powerful, but unfortunately this also means that when you design EPL you need to know how time passes and what event ordering is available or not. You can run Esper in an environment that...
View ArticleEsper-8 Conceptual Differences to Older Versions
This section overviews conceptual changes and is not an all-inclusive statement of changes. It is intended to provide background information. Removed CGLIB Dependency As the compiler generates all the...
View ArticleEsper-8 Migrating Configuration From Older Versions
Introduction Configuration now has 3 sections: Common section: All configuration common to the compiler and the runtime Compiler section: Configuration that applies to the compiler only Runtime...
View ArticleEsper-8 Migrating API Uses From Older Versions
This page provides per-interface information on the API changes. It lists the Esper-7 class name and underneath it lists all removed methods, all changed methods and all new methods. When there were no...
View ArticleEsper-8 Migrating Step-By-Step For Existing Applications
The instructions herein are meant to be used together with the remaining material on migrating. They provide an outline for moving an application to Esper 8. Classpath Changes Remove CGLib from...
View ArticleEsper-8 Migrating EPL from Older Versions
There are no EPL changes between Esper-7 and Esper-8 other than as documented below. The execution of EPL is the same between the versions. URI Use in EPL Esper-7 allowed the use of the engine-URI to...
View ArticleEsper-8 Migrating What is Deprecated
In Esper-8, we removed the runtime configuration API namely ConfigurationOperations and EPAdministrator#getConfiguration. The methods therein duplicated regular configuration and are available using...
View ArticleCompiling Streaming SQL to Byte Code with Esper Complex Event Processing
Today, the Esper team is proud to announce the first compiler that turns Streaming SQL into JVM byte code, available with the just-released Esper version 8.0.0 as of November 21, 2018. Streaming SQL...
View ArticleHow the Esper Compiler Reduces Heap Memory and Improves Performance by...
The aggregation function “avg” returns the average of a numeric value. The runtime maintains a count and a total for each average that is must compute. To illustrate, imagine events that have 10...
View ArticlePerformance Gains Compiling EPL Expressions to Byte Code with Version 8
The Esper version 8 compiler produces JVM byte code from common EPL expressions such as a+b. For the purpose of computing the sum these are the steps: Downcast the event underlying objectObtain the...
View ArticleJSON Deserialize Performance
Esper version 8.2.0 handles JSON documents directly, without the need to create a class. It does so by supporting EPL create-schema for JSON, with the EPL compiler producing a suitable streaming JSON...
View ArticlePerformance Gains from Class Production for Compound Keys
There are many places in EPL that take one or more key expressions as parameters. For instance, in the group-by clause, there can be multiple expressions. The EPL compiler, starting with version...
View Article
