From: Olivier Houchard <cognet@ci0.org>
Date: Wed, 25 Mar 2020 18:41:03 +0000 (+0100)
Subject: MINOR: servers: Add a counter for the number of currently used connections.
X-Git-Tag: v2.2-dev6~74
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf612a0457bd9e658d772dc426064d3865c89ff7;p=thirdparty%2Fhaproxy.git

MINOR: servers: Add a counter for the number of currently used connections.

Add a counter to know the current number of used connections, as well as the
max, this will be used later to refine the algorithm used to kill idle
connections, based on current usage.
---

diff --git a/include/proto/connection.h b/include/proto/connection.h
index f05a4524a4..30730f0ce1 100644
--- a/include/proto/connection.h
+++ b/include/proto/connection.h
@@ -479,6 +479,11 @@ static inline void conn_free(struct connection *conn)
 		_HA_ATOMIC_SUB(&srv->curr_idle_conns, 1);
 		_HA_ATOMIC_SUB(conn->flags & CO_FL_SAFE_LIST ? &srv->curr_safe_nb : &srv->curr_idle_nb, 1);
 		_HA_ATOMIC_SUB(&srv->curr_idle_thr[tid], 1);
+	} else {
+		struct server *srv = objt_server(conn->target);
+
+		if (srv)
+			_HA_ATOMIC_SUB(&srv->curr_used_conns, 1);
 	}
 
 	conn_force_unsubscribe(conn);
diff --git a/include/proto/server.h b/include/proto/server.h
index 575e922811..2847a8cf25 100644
--- a/include/proto/server.h
+++ b/include/proto/server.h
@@ -261,6 +261,7 @@ static inline int srv_add_to_idle_list(struct server *srv, struct connection *co
 			_HA_ATOMIC_SUB(&srv->curr_idle_conns, 1);
 			return 0;
 		}
+		_HA_ATOMIC_SUB(&srv->curr_used_conns, 1);
 		MT_LIST_DEL(&conn->list);
 		conn->idle_time = now_ms;
 		if (is_safe) {
diff --git a/include/types/server.h b/include/types/server.h
index 0ffebb4752..1e5e031a7d 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -230,6 +230,8 @@ struct server {
 	unsigned int curr_idle_conns;           /* Current number of orphan idling connections, both the idle and the safe lists */
 	unsigned int curr_idle_nb;              /* Current number of connections in the idle list */
 	unsigned int curr_safe_nb;              /* Current number of connections in the safe list */
+	unsigned int curr_used_conns;           /* Current number of used connections */
+	unsigned int max_used_conns;            /* Max number of used connections (the counter is resetted at each connection purges */
 	unsigned int *curr_idle_thr;            /* Current number of orphan idling connections per thread */
 	int max_reuse;                          /* Max number of requests on a same connection */
 	struct eb32_node idle_node;             /* When to next do cleanup in the idle connections */
diff --git a/src/backend.c b/src/backend.c
index d500a8ae72..ccf06b8171 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1350,6 +1350,14 @@ int connect_server(struct stream *s)
 		srv_cs = NULL;
 	}
 
+	if (srv_conn && srv) {
+		_HA_ATOMIC_ADD(&srv->curr_used_conns, 1);
+		/* It's ok not to do that atomically, we don't need an
+		 * exact max.
+		 */
+		if (srv->max_used_conns < srv->curr_used_conns)
+			srv->max_used_conns = srv->curr_used_conns;
+	}
 	if (!srv_conn || !sockaddr_alloc(&srv_conn->dst)) {
 		if (srv_conn)
 			conn_free(srv_conn);