This section provides further information on HTTP Compression.

How to change compression options on an Avi Load Balancer SE using the CLI?

HTTP compression option on an SE is changed using the configure applicationprofile command using CLI. Log in to the shell mode and follow the steps mentioned below to change the compression profile using CLI.

[admin-cntrl]> configure applicationprofile <name of the profile>
[admin-cntrl]:applicationprofile> http_profile
[admin-cntrl]: applicationprofile:http_profile>compression_profile

Are the changes related to compression applied instantly across SEs or only to new SEs created after settings have been changed?

Any change related to HTTP compression option is applied through the application profile instantly and only to new client connections.

How is client RTT related to the compression applied?

Aggressive compression option compresses the data by nearly 80%, requiring more CPU resource on both the SE and the client. Aggressive compression requires less bandwidth for transmission. Normal compression has 75% compression ratio and provides a good balance between CPU and bandwidth. Based on the client RTT, the following criteria decide compression action.

  • If rtt > max_low_rtt, normal compression is applied.

  • If rtt > min_high_rtt, aggressive compression is applied.

  • If max_low_rtt is changed from default (10 ms) to 1 ms, compression is applied always.

How to add the maximum and the minimum RTT values?

The maximum and minimum RTT values are configured using the se_dp_compression command from the configure serviceengineproperties mode.

[admin-cntrl]> configure serviceengineproperties
[admin-cntrl]: seproperties> se_runtime_properties
[admin-cntrl]: seproperties:se_runtime_properties> se_dp_compression
[admin-cntrl]: seproperties:se_runtime_properties:se_dp_compression> max_low_rtt 1
[admin-cntrl]: seproperties:se_runtime_properties:se_dp_compression> save
[admin-cntrl]: seproperties:se_runtime_properties> save
[admin-cntrl]: seproperties> save

Why does the Avi Load Balancer not always use aggressive compression?

Aggressive compression requires more CPU cycles. Under the custom compression mode, the aggressive compression level compresses the data by nearly 80%, requiring more CPU resource on both the Avi Load Balancer and client and less bandwidth for transmission. Normal compression level provides about 75% compression and a good balance between CPU and bandwidth.