Chapter 4: Server Load Balancing > Configuring compression rules

Configuring compression rules

To offload compression from your backend servers, you can configure FortiADC to perform HTTP compression on behalf of the server.

The following content types can be compressed:

Not all HTTP responses should be compressed. Compression offers the greatest performance improvements when applied to URLs whose media types include repetitive text such as tagged HTML and JavaScript. Files that already contain efficient compression such as GIF images usually should not be compressed, as the CPU usage and time spent compressing them will result in an increased delay rather than network throughput improvement. Plain text files where no words are repeated, such as configurations with unique URLs or IPs, also may not be appropriate for compression.

Before you begin:

Compression is not enabled by default. After you have configured a compression rule, you can select it in the profile configuration. To enable compression, select the profile when you configure the virtual server.

To configure compression:
  1. Go to Server Load Balance > Profile.
  2. Click the Compression tab.
  3. Click Add to display the configuration editor.
  4. Complete the configuration as described in Table 12.
  5. Save the configuration.

 Table 12:   Compression configuration
Settings Guidelines

Name

Configuration name. Valid characters are A-Z, a-z, 0-9, _, and -. No spaces. You reference this name in the profile configuration.

Note: After you initially save the configuration, you cannot edit the name.

URI List Type

Specify whether to include or exclude items in the list from compression.

URI List

Click Add and specify URIs to build the list. You can use regular expressions.

Content Types

Click Add and select from the following content types to build the list:

  • application/javascript
  • application/soap+xml
  • application/x-javascript
  • application/xml
  • text/css
  • text/html
  • text/javascript
  • text/plain
  • text/xml
  • custom

Note: The "custom" option allows you to specify almost any content/media type, including image files in .JPG, .PNG, and .BMP formats. The default is */*, which means any content/media type.

 

You can use the CLI to configure advanced options:

config load-balance compression

edit 1

set cpu-limit {enable | disable}

set max-cpu-usage <percent> -- max cpu usage for compression

set min-content-length <bytes> -- min bytes for compression

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