The UltraESB is an Enterprise Service Bus [ESB] that facilitates the integration of messages between different systems; both within an organization and beyond - with its partners and users. These "messages" maybe HTTP/S messages (such as SOAP, REST, JSON, XML, Hessian, AS2, HTML, Binary, Text etc) or messages over many other transports such as JMS, FTP/S, SFTP, File, Email, TCP, MLLP/S etc, containing different types of payloads such as SOAP, XML, Text, CSV, EDI, HL7, JSON, Map etc.

The UltraESB from AdroitLogic has deep support for the HTTP/S protocols,and the ability to load balance or fail over requests between multiple backend systems, using round-robin, weighted or random algorithms. Although primarily targeted for OA as an ESB, it can even be used as a web proxy replacing Apache+mod_jk.

The UltraESB also allows HTTP level failures, SOAP faults etc from a server to cause a fail-over to another instance, as well as validation of a successful response by a custom ResponseValidator - before accepting it as a valid response to be sent back to the client. This allows the UltraESB to detect for example that a HTTP 200 response that states "Service is not active" to be identified as a failure and fail-over the request to another instance. Additionally, the UltraESB could easily read or write cookies, HTTP headers etc much easily.

This article describes a scenario where the UltraESB is used to front two Tomcat servers with sticky load balancing with fail-over, and compares it to a similar setup with Apache2+mod_jk

Using the UltraESB to proxy and load balance requests to Tomcat

Edited by: Cameron McKenzie on Apr 20, 2010 9:10 AM

This article describes a scenario where the UltraESB is used to front two Tomcat servers with sticky load balancing with fail-over, and compares it to a similar setup with Apache2+mod_jk

The more I read this the more I ask myself "why would one do it?!?"

This article describes a scenario where the UltraESB is used to front two Tomcat servers with sticky load balancing with fail-over, and compares it to a similar setup with Apache2+mod_jk

The more I read this the more I ask myself "why would one do it?!?"

Apache2+mod_jk would be good to load balance and failover when hosting a plain web application, however when Tomcat is hosting a service oriented backend - e.g. SOAP, REST, JSON, Hessian services - Apache+mod_jk really cannot do much with the payload if required - whereas the UltraESB can! Hence you can validate, transform, log, route etc, along with load balancing and sticky failover support; thus eliminating the Apache2+mod_jk layer as well with the ESB

Ok, but I don't think too many people use apache to loadbalance a soap or rest backend. Probably a different title (something like "Using ultrausb to load balance a service oriented backend") would have made a better selling point

NGINX as Web Frontend/Reverse Proxy:

- server static contents

- gzip responses

HAProxy:

- session sticky load balancing

- health check for the jetty nodes

- load balancing weighting depending on performance of the jetty node possible