The Apache Software Foundation has released Apache Synapse 1.0; simultaneously, WSO2, the company behind Axis2, has released a commercial offering based on Synapse, called WSO2 ESB 1.0.
According to the announcement,
Apache Synapse is a simple and highly effective Web Services intermediary and SOA framework. It can be added to your existing network very simply either as a services gateway or as an HTTP proxy. Once Apache Synapse is mediating your service requests it can perform many functions including routing, load-balancing, transformation and protocol switching. Apache Synapse can be used to build an Enterprise Service Bus (ESB) or Service Oriented Architecture (SOA).
The main features of Synapse include:
- Support for XML/HTTP, JMS, SOAP 1.1/1.2, WS-Addressing, MTOM binary attachments
- Simple protocol switching between XML/HTTP (POX) and SOAP, JMS and HTTP
- Built in support for XPath and Regex based routing, XSLT-based transformations
- High-performance non-blocking HTTP and HTTPS support (based on Apache HttpCore)
- Load-balancing, failover and throttling support
- Support for advanced Web Services standards
- WS-ReliableMessaging
- WS-Security
- WS-Policy
- JMS support including text, binary, XML and SOAP/JMS
- Logging and header-manipulation
- Extensible via scripting languages including JavaScript, Groovy and Ruby
- Custom Java classes or Spring Framework assemblies allow Synapse to be extended
- Extensibility model allows the core XML configuration language to be enhanced by plugin JARs
- Support for timeouts, fault handling and recovery
- A large number of default samples including content-based routing, XSLT, WS-Security and other topics
- Built in test/sample server based on Apache Axis2 for prototyping and testing
- Ability to load scripts, metadata, configuration and resources from a remote registry
- Optional dynamic update to routing tables and other configuration
- Support for JDK 1.4 and 1.5
As opposed to Axis2, Synapse is not programming environment. Instead, it is either configured and managed via an XML config file (in case of Synapse) or a graphical UI (in case of WSO2 ESB). InfoQ covered Synapse's graduation from incubator status back in January; since then, Synapse has been upgraded to use Apache Axis2 1.2, and expanded to include the non-blocking HTTP and HTTPS transport. In addition to sample and documentation improvements, suppport for WSDL endpoints and high availability features has been extended.
InfoQ followed up with WSO2 CTO Paul Fremantle on the occasion of the 1.0 release. Obviously, the WSO2 ESB comes with commercial support and training provided by WSO2; in addition, it features a Web UI for administration and a registry. According to an entry in Paul's blog,
[W]we have built an internal registry and repository, that you can manage using the Web UI. This means that you can store, manage and use all the resources that are needed - WSDLs, URLs, XSLTs, Scripts, WS-Policies, Synapse.xmls, etc, in a single place. This is - in my opinion - one of the key aspects to really building an ESB with Synapse (or any other product). We have further enhancements to do in this area, so keep your eyes peeled.
When asked about the registry support included with the tool, Paul Fremantle clarified,
Synapse can use a registry that offers up XML or other config via a HTTP GET interface or file system. The "registry" that is part of the ESB is basically a file-system based way of managing the resources you need (WSDL, WS-Policy, XSLTs, Synapse config XMLs, etc).
We also asked Paul about the criteria used to decide whether to use Synapse/ESB or Axis2/WSAS (WSAS is WSO2's commercial offering based on Axis2):
Firstly the ESB and Synapse should both interoperate with any other SOAP or XML compliant system (including via JMS). The ESB is really a management, routing and monitoring system. Its not designed to host actual real services, but only virtual services, which are actually implemented by real services hosted elsewhere. So you would use Axis2/WSAS to build real services, but you would use the ESB or Synapse to create a bus (a virtualized, managed and consistent set of services) out of a set of services hosted elsewhere, possibly in WSAS, Axis2, Axis1, .NET, Perl, PHP, JMS, etc.
Paul claims WSO2's ESB (and by extension, Synapse) vastly outperforms another, unnamed leading commercial ESB:
The ESB has been designed to be blisteringly fast. Now we can't name names (because of the usual license agreement carp that proprietary vendors do), but we've tested the WSO2 ESB against a leading proprietary/closed-source ESB. Our figures show we can do simple routing 20% faster, content-based routing 30% faster and XSLTs 100% faster. We will publish the performance data soon. We have a completely non-blocking async model - even for HTTP and HTTPS, meaning we can scale to handle thousands of concurrent connections without dropping any.
WSO2 has made the results, including information about the benchmark setup, public.
The Apache Synapse code and binaries are available from the website at http://ws.apache.org/synapse