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Event Series Intelligence

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Minimal Requirements

Runs on any Java 8 or newer JVM
Fully embeddable

Supported Platforms

Windows, Linux, Solaris, AIX
32bit and 64bit
Runs on any Java 8 or newer JVM

Supported Browsers

Modern browser with HTML 5, JavaScript and web sockets

Supported Containers (*)

(*) Esper does not require any container

Self-contained (standalone)
Any Java AS (requires custom integration)
Any Java ESB (requires custom integration)

Supported Databases (*)

Oracle (x)
MySQL (x)
SQLServer (x)
Any RDBMS with JDBC driver
(*) for use with Esper and EsperIO
(x) when choosing EsperHA database storage option

Esper: Event Processing for Java

Event Series Analysis and Complex Event Processing for Java
  • Expressive Event Processing Language: continuous queries, aggregation, joins, causality and missing events, joins to historical data, output flow control...
  • Rapid development and deployment
  • High throughput, low latency
  • Standalone or embedded, open API
  • Multi platform support
  • Open source or commercial license for redistribution

Esper is an open source event series analysis and event correlation engine (CEP). Commercial support is available. Commercial licensing is mandatory for redistribution.

Esper solves a complex set of problems that current request/reply architectures do not solve: how to make meanings of all events flowing through your system at the speed of your business? How to preserve flexibility? How to handle massively growing data volumes?

It enables you to detect rich situations in event series (historical or currently-arriving) and to trigger custom actions when event conditions occur among event series. Esper is designed for high volume event correlation where millions of events coming in would make it impossible to store them all to later query them using classical database architectures.

CEP and event series analysis have emerged out of years of research in the field of active database, continuous queries and stream processing and are now being widely used in modern latency-sensitive architectures such as algorithmic trading systems, fraud or intrusion detection and business intelligence or customer relationship management.

Esper provides a rich Event Processing Language (EPL) to express filtering, aggregation, and joins, possibly over sliding windows of multiple event series. It also includes pattern semantics to express complex temporal causality among events (followed-by relationship).


Esper supports a wide variety of event representations, such as Java beans, XML document, legacy classes, or simple name value pairs. It can be easily embedded in an existing Java application or middleware to add event-driven capabilities to existing platforms without paying high serialization cost or network latency for every message received and action triggered.

Once event queries and pattern statements are registered in the Esper core container, event data gets analyzed and can trigger arbitrary logic bound to the engine in the form of Plain Old Java Objects. This enables leveraging any existing Java technology and ensures easily connection to existing SOA building blocks.

Simple yet powerful

Esper building blocks

Esper does not sacrifice simplicity for providing a rich feature set. Its POJO (Plain Old Java Object) based programming model and core API enable any Java developer to enrich an existing application with Event Series Intelligence now, leveraging today' world technologies such as lightweight containers, object oriented programming techniques and XML document management.

Fully embeddable in existing architectures

Esper can fully be embeddable in existing Java based architectures such as Java Application Servers or Enterprise Service Bus. It can also be used as a standalone container in any existing standalone applications. This can help replace legacy in-house developed event series analysis logic with far less risks than other big-bang approaches.

Open Source as a driving force

Esper is being developed under an open source license and community process, which ensures features are being discussed according to user requirements and feedback. It also significantly decreases the cost of acquisition. EsperTech provides mission critical support and services to keep your total cost of ownership under control; further ensuring key expectations are met in today enterprise grade environments.

EsperTech provides commercial license for redistribution, and enterprise grade extensions, such as high-availability, under non open source licenses for mission critical environments.

Open Source