By default, the 4D Web server converts the extended characters in the dynamic and static Web pages according to HTML standards before sending them. They are then interpreted by the browsers.
You can set the Web server so that the extended characters are sent “as is”, without converting them into HTML entities. This option has shown a speed increase on most foreign operating systems (especially the Japanese system).
To do this, check the Send Extended Characters Directly option.
The Standard Set drop-down list allows you to define the set of characters to be used by the 4D Web server. By default, the character set is UTF-8.
The Web server of 4D can use keep-alive connections. The keep-alive option allows you to maintain a single open TCP connection for the set of exchanges between the Web browser and the server to save system resources and to optimize transfers.
The Use Keep-Alive Connections option enables or disables keep-alive TCP connections for the Web server. This option is enabled by default. In most cases, it is advisable to keep this option check since it accelerates the exchanges. If the Web browser does not support connection keep alive, the 4D Web server automatically switches to HTTP/1.0.
The 4D Web server keep-alive function concerns all TCP/IP connections (HTTP, HTTPS). Note however that keep-alive connections are not always used for all 4D Web processes.
In some cases, other optimized internal functions may be invoked. Keep-alive connections are useful mainly for static pages.
Two options allow you to set how the keep-alive connections work:
- Number of requests by connection: Allows you to set the maximum number of requests and responses able to travel over a connection keep alive. Limiting the number of requests per connection allows you to prevent server flooding due to a large number of incoming requests (a technique used by hackers).
The default value (100) can be increased or decreased depending on the resources of the machine hosting the 4D Web server. - Timeout: This value defines the maximum wait period (in seconds) during which the Web server maintains an open TCP connection without receiving any requests from the Web browser. Once this period is over, the server closes the connection.
If the Web browser sends a request after the connection is closed, a new TCP connection is automatically created. This operation is not visible for the user.