Siddhi
Siddhi is a free, open-source stream and complex event processing engine for building event-driven applications.
What Siddhi is
Siddhi is a free, open-source stream and complex event processing engine for building event-driven applications. It uses Siddhi Streaming SQL, written in a graphical or text editor, to consume, transform, integrate, and publish events. Documented uses include real-time analytics, data integration, notification management, and adaptive decisions. Processing supports filtering, preprocessing, event and time windows, aggregations, patterns, sequences, rules, and online or pretrained machine-learning models. Connectors cover Kafka, NATS, RabbitMQ, JMS, MQTT, HTTP, gRPC, Amazon SQS, Google Pub/Sub, email, files, and WebSocket. Supported formats include JSON, XML, Avro, Protobuf, text, binary, key-value, and CSV, with data-store integrations such as MySQL, Oracle, MSSQL, Postgre, Redis, MongoDB, HBase, Cassandra, Solr, and Elasticsearch. Siddhi runs as Java or Python libraries, microservices, Docker workloads, or Kubernetes deployments. Tooling includes query editors, an event simulator, and CI/CD test framework support. It is self-hosted under Apache License 2.0; documentation specifies 128 MB minimum memory and JDK 8 or 11 for execution modes.
Good
- Open-source Apache License 2.0
- Supports graphical and text query editing
- Broad messaging, database, and service connectors
- Handles windows, patterns, aggregations, and rules
- Runs from libraries through Kubernetes
Watch out
- Self-hosted deployment requires infrastructure management
- Documentation lists JDK 8 or 11 requirements
- PySiddhi support explicitly lists macOS and Linux
- Project says future releases come through WSO2 Enterprise Integrator
Who it suits
Siddhi suits developers building self-hosted, event-driven systems with streaming SQL, stateful processing, and many connectors. It is relevant for analytics, integration, notifications, and rule-based decisions.
Verdict
Siddhi offers a broad event-processing toolkit with SQL-like logic, connectors, stateful operations, and multiple deployment models. Its self-hosted nature and stated runtime requirements should guide implementation planning.
The facts
Each one read from Siddhi's own pages, with the date it was checked.
What it does
- Analytics and rules
- Features include event-window and time-based aggregation, complex event patterns and sequences, rule processing, and online or pretrained machine-learning models.checked 5 Oct 2026
- Connectors
- The site lists integrations with messaging systems including NATS, Kafka, and JMS, plus databases, HTTP and gRPC services, filesystems, and email.checked 5 Oct 2026
- Data formats
- The site lists JSON, XML, Avro, Protobuf, text, binary, key-value, and CSV message formats.checked 5 Oct 2026
- Data stores
- Listed data-store integrations include MySQL, Oracle, MSSQL, Postgre, Redis, MongoDB, HBase, Cassandra, Solr, and Elasticsearch.checked 5 Oct 2026
- Deployment
- Siddhi can run embedded as a Java or Python library, as a microservice on bare metal or a VM, in Docker, or on Kubernetes.checked 5 Oct 2026
- Deployment automation
- The site describes test framework support for unit, integration, and black-box tests as part of a CI/CD workflow.checked 5 Oct 2026
- Editor
- Siddhi tooling includes text and graphical query editors and an event simulator for testing Siddhi applications.checked 5 Oct 2026
- Formats and sources
- The features documentation lists JSON, XML, Avro, Protobuf, text, binary, key-value, and CSV formats, along with sources including RabbitMQ, MQTT, Amazon SQS, Google Pub/Sub, and WebSocket.checked 5 Oct 2026
- Integrations
- Supported event sources and destinations listed include Kafka, NATS, RabbitMQ, HTTP, gRPC, JMS, MQTT, Amazon SQS, Google Pub/Sub, email, files, and WebSocket.checked 5 Oct 2026
- License
- The Siddhi license page identifies Apache License 2.0.checked 5 Oct 2026
- Operating systems
- The download page lists MacOS and Linux as supported platforms for PySiddhi 5.1.0.checked 5 Oct 2026
- Processing features
- The features documentation lists event filtering and preprocessing, time and event windows, aggregations, pattern detection, and rule processing.checked 5 Oct 2026
- Product
- Siddhi is an open source stream and complex event processing engine for building event-driven applications.checked 5 Oct 2026
- Project status
- The homepage says Siddhi has been integrated into WSO2 Enterprise Integrator and future releases will be made as part of EI.checked 5 Oct 2026
- Query language
- Processing logic can be written in Siddhi Streaming SQL through a graphical editor or source editor.checked 5 Oct 2026
- Reliability
- The homepage claims zero event loss and exactly-once event processing.checked 5 Oct 2026
- Requirements
- The documentation specifies 128 MB minimum memory, recommends 500 MB and two cores, and lists JDK 8 or 11 for execution modes.checked 5 Oct 2026
- Security
- WSO2 asks vulnerability reports to be sent privately to its security mailing list and says initial response time will be under one hour.checked 5 Oct 2026
- Security reporting
- The security page asks users to report vulnerabilities privately to WSO2’s security mailing list before public disclosure and says initial response is under one hour.checked 5 Oct 2026
- Streaming SQL
- Processing logic can be written as SQL-like scripts for consuming, processing, integrating, and publishing events.checked 5 Oct 2026
- Support
- The site links to community support resources including a mailing list, contribution information, and security reporting.checked 5 Oct 2026
- Use cases
- The site describes real-time analytics, data integration, notification management, and adaptive decision-making as use cases.checked 5 Oct 2026
- What it does
- Siddhi is an open-source stream and complex event processing platform for building event-driven applications.checked 5 Oct 2026
Where it runs
- Supported platforms
- The PySiddhi download section explicitly lists macOS and Linux as supported platforms.checked 5 Oct 2026
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