HTTP Support

FioranoMQ supports HTTP as the transport protocol between JMS clients and MQ Servers. This allows JMS communications to flow through corporate firewalls/proxies. Implementing this feature insulates the protocol layer from JMS application development. The client side environment is responsible for determining the protocol to be used for communication. All protocols - TCP, Secure TCP (JSSE), and HTTP behave in a similar manner. Selecting the protocol to be used is based on the configuration of the application developer. Synchronous and asynchronous communications are available regardless of protocol choice.

HTTP is typically used to communicate across the internet. If the FioranoMQ Server is to directly process messages received from clients over the internet, it must be deployed in a manner similar to a web-server. The HTTP support in FioranoMQ provides the necessary features that make it function as a web server enabling it to handle HTTP requests. Using HTTP Tunneling a direct connection between client and server can be established.

Following topics are covered in this chapter:

Client Side Changes

While switching protocol from TCP to HTTP, the following changes are required:

• All additional parameters need to be marked as JNDI.
• If jndi.properties file is used to specify parameters, the application code need not be modified. In such cases, an HTTP Enabled Connection factory needs to be used.
• Including of HTTPClient.zip file in classpath.

Proxy Servers

HTTP support of FioranoMQ provides seamless communication via proxy servers. Most proxy servers including- Microsoft ISA server, Wingate, and WinProxy among others – can be used to connect to the FioranoMQ Server. FioranoMQ Client libraries allow developers to set the Proxy Address and Port in the client applications. These can also be set as Java VM Properties.

Proxy Authentication

FioranoMQ supports both "Basic" and "Digest" authentication for communication through proxies. Various Proxy Authentication parameters such as the Authentication Realm, username and password can be specified through client applications using the environment variables.
Authentication is required within the instance of a VM. FioranoMQ caches the authentication information and uses it for other connections.

Tunneling

This section discusses how JMS Clients operate in networks where firewalls are present. FioranoMQ allows enterprise clients to extend beyond corporate firewalls by providing both HTTP Tunneling and tunneling through SOCKS enabled Proxy servers. FioranoMQ provides Tunneling support for clients along with all JMS functionalities.

Refer to the Tunneling Through Firewalls section for more details.

HTTP Pinging

To get the server to detect the clients that have been disconnected from the server pinging needs to be implemented over HTTP as well. This enables a 'clean up' of resources used by clients that have been disconnected or timed out. To implement this feature, the client library must continuously ping the server at predefined intervals. The server can be configured to perform this action. Pinging is essential for the HTTP support of FioranoMQ and is set as the default feature in the case of HTTP connections. Due to attributes of HTTP, there are limitations in detecting control-C (or terminating the application abruptly) related issues from the client. It is expected that the JMS client application programmers perform an explicit connection.close() operation to enable the server to detect client disconnections. Not doing an explicit close can result in inconsistent message reception and delivery.