|Developer(s)||Apache Software Foundation|
|Stable release||2.1 / January 6, 2012|
|Type||Enterprise Service Bus|
|License||Apache License 2.0|
Apache Synapse is a simple, lightweight and extremely high performance open source enterprise service bus (ESB) and mediation engine. It began incubation at the Apache Software Foundation on August 22, 2005, and graduated as a sub project of the Apache Web Services project on January 2, 2007. After implementing extensive support for legacy systems integration, it moved out from the Apache Web Services project as a Top Level Project (TLP) of the Apache Software Foundation on the February 5, 2008. Apache Synapse is released under the Apache License.
Synapse supports the creation of Proxy Services, which allows users to easily create virtual services on the ESB layer to front existing services. Existing services may be SOAP, POX/REST services over HTTP/S, as well as SOAP or legacy services over JMS, Apache VFS file systems (e.g. s/ftp, file, zip/tar/gz, webdav, cifs etc.), Mail systems (e.g. pop3, imap, smtp), Financial Information eXchange (FIX), Hessian, AMQP etc. The proxy services allows easy switching of transport, interface (WSDL/Schema/Policy), message format (SOAP 1.1, 1.2/POX/REST, Text, Binary/Hessian etc.), QoS (WS-Addressing, WS-Security, WS-Reliable Messaging) and message optimization (MTOM/SwA) etc.
Synapse has implemented a non-blocking HTTP/S transport implementation over the Apache HttpComponents/NIO module to handle thousands of concurrent requests using very little resources and threads. This implementation is capable of connection throttling to control the rate at which large messages are read and processed, and thus can handle heavy concurrent loads of large messages using constant memory.