You should consider HTML compression if you have
users who are connected to Sterling Selling and
Fulfillment Foundation over
high latency or low bandwidth network links. HTML compression can
reduce the size of the HTML pages by up to 85%.
Currently, the Sterling Selling and
Fulfillment Foundation Console
UIs have been tested with F5 Big-IP v9 as an off-board HTML compression
engine.
If you were to use a Big-IP, you should be aware
of the following Big-IP specific configuration requirements in the
HTTP Profile configuration tab:
- You need to set the response chunking parameter
to rechunk. The default is preserve. The reason is that Sterling Selling and
Fulfillment Foundation does
not set the content length in the HTTP headers when sending out the
response. With the default setting of preserve, the Big-IP does not
attempt to compress HTML pages that do not have content lengths set.
With the rechunk setting, Big-IP compresses the response chunks
as they are received. More importantly, the Big-IP can forward along
the compressed chunks without waiting for the entire HTML page to
be compressed.
- Big-IP allows you to specify the amount of compression
processing that it attempts. The setting can range from Level 1 which
tries a minimal compression in favor of processing speed to Level
9 which tries to find the most compression. We found that Level 1
compression was able to get up to 85% compression and that the benefits
from Level 9 undetectable. As a result, we defaulted to testing with
Level 1 compression.
- We set the compression buffer size to 128KB instead
of the default of 4KB. The general thought is that the buffer size
should be able to store the entire compressed response in order to
set the content header length. In our testing, we didn't see
any appreciable differences between 4KB and 128KB. This may be due
to the fact that we had already set response chunking to rechunk -
as a result, the Big-IP does not have to set the content length on
the compressed response. However, we were advised to set the buffer
size to at least 128KB.
We recognize that there are other HTML compression
technologies available including Apache deflate module and Juniper
DX application acceleration devices. Please keep in mind that we have,
to date, only tested against the F5 Big-IP v9.
Please also keep in mind that the compression is
only certified for the Application Console. The Applications Manager
and the System Management Console do not support compression. The
VT220 terminal screens are small and should not require compression.