With 1.8.x releases, haproxy consumes a lot of memory when
using 1,000,000 as default connection_limit.
This commit introduces a new configuration option for the Amphora
provider: [haproxy_amphora].default_connection_limit (defaulted to
50,000). This value is used when creating a listener with -1 (which is
the default) as connection_limit, or when unsetting connection_limit in
a listener.
Updating an existing listener by setting connection_limit to -1 also
sets it to default_connection_limit.
The global connection_limit for a load balancer is the sum of the
connection_limit of the listeners, but it cannot be over
HAPROXY_MAX_MAXCONN (which is still 1,000,000).
Story: 2007794
Task: 40046
Change-Id: Ibc525d9a046a5ab7f090a942459d80a2df66ae2e
(cherry picked from commit f4305e036c)
e82820126f