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Parameter Name



Possible Values

Default Value


If the outgoing messages should be sent through an HTTP proxy server, use this parameter to specify the target proxy.


A host name or an IP address



The port through which the target proxy accepts HTTP traffic.


A positive integer less than 65535



The list of hosts to which the HTTP traffic should be sent directly without going through the proxy.


A list of host names or IP addresses separated by '|'



Setting this parameter to true is vital for reliable messaging and a number of other scenarios to work properly.





HTTP PassThrough transport

HTTP PassThrough Transport is the default, non-blocking HTTP transport implementation based on HTTP Core NIO and is specially designed for streaming messages. It is similar to the old message relay transport, but it does not care about the content type and simply streams all received messages through. It also has a simpler and cleaner model for forwarding messages back and forth. It can be used as an alternative to the NHTTP transport. 

The HTTP PassThrough Transport is enabled by default. If you want to use the NHTTP transport instead, uncomment the relevant NHTTP transport entries in axis2.xml and comment out the HTTP PassThrough transport entries. The PassThrough Transport does not require the binary relay builder and expanding formatter.


Connection throttling

With the HTTP PassThrough and HTTP NIO transports, you can enable connection throttling to restrict the number of simultaneous open connections. To enable connection throttling, edit the <PRODUCT_HOME>/repository/conf/ (for the HTTP NIO transport) or <PRODUCT_HOME>/repository/conf/ (for the PassThrough transport) and add the following line: max_open_connections = 2

This will restrict simultaneous open incoming connections to 2. To disable throttling, delete the max_open_connections setting or set it to -1.


Connection throttling is never exact. For example, setting this property to 2 will result in roughly two simultaneous open connections at any given time.