9.2. HTTP compression

filter compression

The HTTP compression has been moved in a filter in HAProxy 1.7. "compression"
keyword must still be used to enable and configure the HTTP compression. And
when no other filter is used, it is enough. When used with the cache enabled,
it is also enough. In this case, the compression is always done after the
response is stored in the cache. But it is mandatory to explicitly use a filter
line to enable the HTTP compression when at least one filter other than the
cache is used for the same listener/frontend/backend. This is important to know
the filters evaluation order.

See also : “compression“ and section 9.4 about the cache filter.