BUG/MINOR: server: fix the connection release logic regarding nearly full conditions

There was a logic bug in commit ddfe0743d ("MEDIUM: server: use the two
thresholds for the connection release algorithm"): instead of keeping
only our first idle connection when FDs become scarce, the condition was
inverted resulting in enforcing this constraint unless FDs are scarce.
This results in less idle connections than permitted to be kept under
normal condition.

No backport needed.

diff --git a/include/haproxy/server.h b/include/haproxy/server.h
index 1fa1b2d..6ab6c07 100644 (file)
--- a/include/haproxy/server.h
+++ b/include/haproxy/server.h
@@ -255,11 +255,11 @@ static inline int srv_add_to_idle_list(struct server *srv, struct connection *co
            ((srv->proxy->options & PR_O_REUSE_MASK) != PR_O_REUSE_NEVR) &&
            ha_used_fds < global.tune.pool_high_count &&
            (srv->max_idle_conns == -1 || srv->max_idle_conns > srv->curr_idle_conns) &&
-           ((ha_used_fds < global.tune.pool_low_count &&
-             MT_LIST_ISEMPTY(&srv->safe_conns[tid]) &&
+           ((MT_LIST_ISEMPTY(&srv->safe_conns[tid]) &&
              (is_safe || MT_LIST_ISEMPTY(&srv->idle_conns[tid]))) ||
-            (srv->curr_used_conns + srv->curr_idle_conns <
-             MAX(srv->curr_used_conns, srv->est_need_conns) + global.nbthread)) &&
+            (ha_used_fds < global.tune.pool_low_count &&
+             (srv->curr_used_conns + srv->curr_idle_conns <
+              MAX(srv->curr_used_conns, srv->est_need_conns) + global.nbthread))) &&
            !conn->mux->used_streams(conn) && conn->mux->avail_streams(conn)) {
                int retadd;