HTTP-NIO Transport

HTTP-NIO transport is a module of the Apache Synapse project. The two classes that implement the receiver and sender APIs are org.apache.synapse.transport.nhttp.HttpCoreNIOListener and org.apache.synapse.transport.nhttp.HttpCoreNIOSender respectively. These classes are available in the JAR file named synapse-nhttp-transport.jar. The transport implementation is based on Apache HTTP Core - NIO and uses a configurable pool of non-blocking worker threads to grab incoming HTTP messages off the wire.

Transport receiver parameters

In transport parameter tables, literals displayed in italic mode under the "Possible Values" column should be considered as fixed literal constant values. Those values can be directly put in transport configurations.

Parameter Name	Description	Requried	Possible Values	Default Value
port	The port on which this transport receiver should listen for incoming messages.	No	A positive integer less than 65535	8280
non-blocking	Setting this parameter to true is vital for a number of scenarios to work properly.	Yes	true/false	true
bind-address	The address of the interface to which the transport listener should bind.	No	A host name or an IP address	127.0.0.1
hostname	The host name of the server to be displayed in service EPRs, WSDLs etc. This parameter takes effect only when the WSDLEPRPrefix parameter is not set.	No	A host name or an IP address	localhost
WSDLEPRPrefix	A URL prefix which will be added to all service EPRs and EPRs in WSDLs etc.	No	A URL of the form <protocol>://<hostname>:<port>/

Transport sender parameters

Parameter Name	Description	Requried	Possible Values	Default Value
http.proxyHost	If the outgoing messages should be sent through an HTTP proxy server, use this parameter to specify the target proxy.	No	A host name or an IP address
http.proxyPort	The port through which the target proxy accepts HTTP traffic.	No	A positive integer less than 65535
http.nonProxyHosts	The list of hosts to which the HTTP traffic should be sent directly without going through the proxy. When trying to add multiple hostnames along with an asterisk in order to define a set of sub-domains for non-proxy hosts, you need to add a period before the asterisk when configuring proxy server. `".*.abc.my.com\|localhost"`	No	A list of host names or IP addresses separated by '\|'
non-blocking	Setting this parameter to true is vital for a number of scenarios to work properly.	Yes	true/false	true

For more information, see Working with Transports.

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/nhttp.properties (for the HTTP NIO transport) or <PRODUCT_HOME>/repository/conf/passthru-http.properties (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.