Throttle Pipes

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Xitami
Version 2.5b4

Throttle Pipes

What are Throttle Pipes?

One problem with web and FTP sites is that they can consume a large amount of bandwidth. If your site suddenly becomes popular, it can disturb other traffic that needs to work on the same line.

For people who use Xitami to do virtual hosting, it's useful to be able to balance the needs of the different web sites, possibly to provide different qualities of service to different clients.

Xitami lets you send output (and get input) through named 'throttle pipes', which you can visualise as pipes with a specific maximum capacity. For example, a 64Kb pipe will allow 65536 bytes to pass through every second.

By default, Xitami web sites and FTP sites do not use throttle pipes, and run at full speed. You can choose a throttle pipe for a specific web site (virtual host), and for an FTP service. You can also specify the throttle pipe for individual FTP users. All connections that pass through the same throttle pipe share its capacity. So, when you specify the same throttle pipe for five FTP users, these will share its capacity. If you want to give each user the full capacity, you need to define five throttle pipes.

Predefined Throttle Pipes

The predefined throttle pipes are in the file pipedef.xml. This XML file specifies each throttle pipe as an 'instance' of a general pipe definition. So, for instance, it may define two instances of a 64k pipe. Each instance is a real, usable throttle pipe.

Defining New Throttle Pipes

You can edit the pipedef.xml file directly, but it's a better idea to copy it, and edit the copy. Change the server:pipedef option to indicate the new file name.

When you edit the pipedef file, be sure to read the comments at the beginning. These explain the XML syntax that you can use. The XML file is case-sensitive.

Xitami defines pipes in terms of bytes per second, not bits per second (unlike most Internet connections).