Apache Storm vs Esper

Apache Storm is a distributed system for computing over unbounded data streams in real time. It uses spouts, bolts, and topologies to assemble multi-stage computations, supporting realtime analytics, online machine learning, continuous computation, distributed RPC, and ETL. The project describes Storm as scalable and fault-tolerant, with guaranteed data processing, and reports a benchmark above one million tuples per second per node. Integrations include Apache Kafka, HDFS, JDBC databases, JMS, and Redis. Developers can work in local mode in-process or submit topologies to a remote cluster. Storm supports stateful processing and lists JavaScript, Python, Ruby, and C# among supported languages. It is free under Apache License, Version 2.0; source and binary distributions are available, along with Maven Central and an official Docker image. The current release is 3.1.0. Security options include Kerberos/SASL authentication, SimpleACLAuthorizer authorization, and TLS for Thrift RPC and worker messaging; authentication and authorization options are disabled by default.

Esper is a language, compiler, and runtime for complex event processing and streaming analytics in Java and .NET. Its Event Processing Language extends SQL with expressions over events and time. The compiler turns EPL into bytecode that can be packaged in JAR files. Esper and NEsper embed inside Java or .NET processes rather than running as standalone servers. The in-memory runtime is described as memory-efficient and low-latency and does not require external storage or services. Adapters handle CSV, JMS, HTTP, Kafka, database, and socket input and output, with JMX metrics exposure. Queries can join event streams with web services and relational databases through SQL-query or method-invocation joins. Esper Enterprise Edition adds scale-out architecture with elastic scaling, load balancing, fault tolerance, and multi-datacenter support using Apache Kafka and Apache Zookeeper. Listed uses include business-process monitoring, financial applications such as fraud detection, network and application monitoring, and sensor networks. Esper 9.0.0 is listed under GNU GPL (GPL v2); commercial redistribution licenses are available. Production support has Bronze, Silver, and Gold levels, plus a Developer Seat for how-to questions.