DOC: add a few precisions on compression

Please consider the attached patch, I hope it will clarify haproxy's behavior a
bit.
This commit is contained in:
Dmitry Sivachenko 2012-11-28 17:47:11 +04:00 committed by Willy Tarreau
parent 8139b9959f
commit c9f3b45d7a

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@ -1903,16 +1903,23 @@ compression offload
Compression will be activated depending on the Accept-Encoding request
header. With identity, it does not take care of that header.
If backend servers support HTTP compression, these directives
will be no-op: haproxy will see the compressed response and will not
compress again. If backend servers do not support HTTP compression and
there is Accept-Encoding header in request, haproxy will compress the
matching response.
The "offload" setting makes haproxy remove the Accept-Encoding header to
prevent backend servers from compressing responses. It is strongly
recommended not to do this because this means that all the compression work
will be done on the single point where haproxy is located. However in some
deployment scenarios, haproxy may be installed in front of a buggy gateway
and need to prevent it from emitting invalid payloads. In this case, simply
removing the header in the configuration does not work because it applies
before the header is parsed, so that prevents haproxy from compressing. The
"offload" setting should then be used for such scenarios.
with broken HTTP compression implementation which can't be turned off.
In that case haproxy can be used to prevent that gateway from emitting
invalid payloads. In this case, simply removing the header in the
configuration does not work because it applies before the header is parsed,
so that prevents haproxy from compressing. The "offload" setting should
then be used for such scenarios.
Compression is disabled when:
* the server is not HTTP/1.1.