BUG/MINOR: backend: use cum_sess counters instead of cum_conn

This commit is part of a serie to align counters usage between
frontends/listeners on one side and backends/servers on the other.

"stot" metric refers to the total number of sessions. On backend side,
it is interpreted as a number of streams. Previously, this was accounted
using <cum_sess> be_counters field for servers, but <cum_conn> instead
for backend proxies.

Adjust this by using <cum_sess> for both proxies and servers. As such,
<cum_conn> field can be removed from be_counters.

Note that several diagnostic messages which reports total frontend and
backend connections were adjusted to use <cum_sess>. However, this is an
outdated and misleading information as it does reports streams count on
backend side. These messages should be fixed in a separate commit.

This should be backported to all stable releases.

(cherry picked from commit c02ec9a9db205fda124a40a2a87913a0528b0e5b)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 06053bcad9735562b9eacd6e736e2d71153c665d)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 1c8372b1714961f11f943fe2ef6d3e26cf2774ce)
 [ad: context adjustement due to missing proxy_inc_fe_cum_sess_ver_ctr()]
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit d33cbf68d14ee28abf9846c14253f2a62e2f4947)
 [ad: context adjustment due to queue.length named nbpend]
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
6 files changed