From: Aurelien DARRAGON <adarragon@haproxy.com>
Date: Mon, 30 Jun 2025 13:45:44 +0000 (+0200)
Subject: MEDIUM: proxy: add and use a separate last_change variable for internal use
X-Git-Tag: v3.3-dev3~73
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5b1480c9d40dc6f9e4ebe8d0531a1709d9f6c244;p=thirdparty%2Fhaproxy.git

MEDIUM: proxy: add and use a separate last_change variable for internal use

Same motivation as previous commit, proxy last_change is "abused" because
it is used for 2 different purposes, one for stats, and the other one
for process-local internal use.

Let's add a separate proxy-only last_change variable for internal use,
and leave the last_change shared (and thread-grouped) counter for
statistics.
---

diff --git a/include/haproxy/proxy-t.h b/include/haproxy/proxy-t.h
index 993751c5c..2d08a7852 100644
--- a/include/haproxy/proxy-t.h
+++ b/include/haproxy/proxy-t.h
@@ -311,7 +311,7 @@ struct proxy {
 	char flags;                             /* bit field PR_FL_* */
 	enum pr_mode mode;                      /* mode = PR_MODE_TCP, PR_MODE_HTTP, ... */
 	char cap;                               /* supported capabilities (PR_CAP_*) */
-	/* 4-bytes hole */
+	unsigned long last_change;              /* internal use only: last time the proxy state was changed */
 
 	struct list global_list;                /* list member for global proxy list */
 
diff --git a/src/backend.c b/src/backend.c
index 5479d4ddf..56a6d88b0 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -2894,6 +2894,7 @@ void back_handle_st_rdy(struct stream *s)
  */
 void set_backend_down(struct proxy *be)
 {
+	be->last_change = ns_to_sec(now_ns);
 	HA_ATOMIC_STORE(&be->be_counters.shared->tg[tgid - 1]->last_change, ns_to_sec(now_ns));
 	_HA_ATOMIC_INC(&be->be_counters.shared->tg[tgid - 1]->down_trans);
 
@@ -2967,12 +2968,10 @@ no_cookie:
 }
 
 int be_downtime(struct proxy *px) {
-	unsigned long last_change = COUNTERS_SHARED_LAST(px->be_counters.shared->tg, last_change);
-
-	if (px->lbprm.tot_weight && last_change < ns_to_sec(now_ns))  // ignore negative time
+	if (px->lbprm.tot_weight && px->last_change < ns_to_sec(now_ns))  // ignore negative time
 		return px->down_time;
 
-	return ns_to_sec(now_ns) - last_change + px->down_time;
+	return ns_to_sec(now_ns) - px->last_change + px->down_time;
 }
 
 /*
diff --git a/src/proxy.c b/src/proxy.c
index 5e09641a3..e3a56af4c 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -1722,6 +1722,7 @@ int setup_new_proxy(struct proxy *px, const char *name, unsigned int cap, char *
 	}
 
 	px->cap = cap;
+	px->last_change = ns_to_sec(now_ns);
 
 	if (name && !(cap & PR_CAP_INT))
 		proxy_store_name(px);
diff --git a/src/server.c b/src/server.c
index 3fc1cd997..73870574b 100644
--- a/src/server.c
+++ b/src/server.c
@@ -7064,13 +7064,14 @@ static void srv_update_status(struct server *s, int type, int cause)
 	if (prev_srv_count && s->proxy->srv_bck == 0 && s->proxy->srv_act == 0)
 		set_backend_down(s->proxy); /* backend going down */
 	else if (!prev_srv_count && (s->proxy->srv_bck || s->proxy->srv_act)) {
-		unsigned long last_change = COUNTERS_SHARED_LAST(s->proxy->be_counters.shared->tg, last_change);
+		unsigned long last_change = s->proxy->last_change;
 
 		/* backend was down and is back up again:
 		 * no helper function, updating last_change and backend downtime stats
 		 */
 		if (last_change < ns_to_sec(now_ns))         // ignore negative times
 			s->proxy->down_time += ns_to_sec(now_ns) - last_change;
+		s->proxy->last_change = ns_to_sec(now_ns);
 		HA_ATOMIC_STORE(&s->proxy->be_counters.shared->tg[tgid - 1]->last_change, ns_to_sec(now_ns));
 	}
 }