Ability to Rewrite is quite important for any Application deployment for several reasons:

1) To hide the actual path where App/Content is located
2) To replace static URLs from response body based on certain traffic characteristics
3) To be able to insert and send a special header to Application for processing based on request parameters
4) To mask out certain information which is treated as confidential
5) To mask the changes on server/app which needs some changes to client traffic pattern

Similarly there can be numerous such use cases which can be handled by Rewriting specific portion of request and response traffic flow. This provides end user with flexibility to have changes done to the Application or Infrastructure without affecting end clients. The changes done can be accommodate in traffic profile by rewriting the request and response. NetScaler supports ability to rewrite at most granular level of Application traffic through:

• Ability to manipulate URLs before the backend applications see them
• Ability to manipulate HTTP request / response headers
• Ability to manipulate HTTP request/response body on the fly

To do this job NetScaler has different entities and rich set of actions implemented to take care of all such use cases.

• Rewrite Entities:
• Rewrite actions
• Rewrite policies
• Global binding
• Vserver level binding
• Policylabels
• Actions:
§ insert_http_header
§ delete_http_header
§ insert_before
§ insert_after
§ delete
§ replace
§ delete_all
§ replace_all
§ insert_before_all
§ insert_after_all
§ replace_http_res

Beyond all these entities and actions Rewrite feature is developed on AppExpert infrastructure and thus utilizes the powerful expression language to parse through any attribute of client or server side traffic.