Only consider a proxy dead if all subproxy connections are also dead

src/generator.c

@@ -1701,6 +1701,31 @@ static void recruit_subproxy(proxy_instance_t *proxi)
 	create_pthread(&pth, proxy_recruit, proxi);
 }
 
+static void *proxy_reconnect(void *arg)
+{
+	proxy_instance_t *proxy = (proxy_instance_t *)arg;
+	server_instance_t *si = proxy->si;
+	connsock_t *cs = proxy->cs;
+	ckpool_t *ckp = proxy->ckp;
+
+	pthread_detach(pthread_self());
+	proxy_alive(ckp, si, proxy, cs, true, proxy->epfd);
+	return NULL;
+}
+
+/* For reconnecting the parent proxy instance async */
+static void reconnect_proxy(proxy_instance_t *proxi)
+{
+	pthread_t pth;
+
+	create_pthread(&pth, proxy_reconnect, proxi);
+}
+
+static void reconnect_generator(const ckpool_t *ckp)
+{
+	send_proc(ckp->generator, "reconnect");
+}
+
 /* For receiving messages from an upstream pool to pass downstream. Responsible
  * for setting up the connection and testing pool is live. */
 static void *passthrough_recv(void *arg)
@@ -1722,7 +1747,7 @@ static void *passthrough_recv(void *arg)
 	}
 
 	if (proxy_alive(ckp, si, proxi, cs, false, epfd)) {
-		send_proc(ckp->generator, "reconnect");
+		reconnect_generator(ckp);
 		LOGWARNING("Proxy %d:%s connection established",
 			   proxi->id, proxi->si->url);
 	}
@@ -1734,12 +1759,12 @@ static void *passthrough_recv(void *arg)
 		while (!proxy_alive(ckp, si, proxi, cs, true, epfd)) {
 			if (alive) {
 				alive = false;
-				send_proc(ckp->generator, "reconnect");
+				reconnect_generator(ckp);
 			}
 			sleep(5);
 		}
 		if (!alive)
-			send_proc(ckp->generator, "reconnect");
+			reconnect_generator(ckp);
 
 		/* Make sure we receive a line within 90 seconds */
 		ret = epoll_wait(epfd, &event, 1, 90000);
@@ -1749,7 +1774,7 @@ static void *passthrough_recv(void *arg)
 			LOGWARNING("Proxy %d:%s failed to read_socket_line in proxy_recv, attempting reconnect",
 				   proxi->id, proxi->si->url);
 			alive = proxi->alive = false;
-			send_proc(ckp->generator, "reconnect");
+			reconnect_generator(ckp);
 			continue;
 		}
 		/* Simply forward the message on, as is, to the connector to
@@ -1771,6 +1796,23 @@ static proxy_instance_t *current_proxy(gdata_t *gdata)
 	return ret;
 }
 
+static bool subproxies_alive(proxy_instance_t *proxy)
+{
+	proxy_instance_t *subproxy, *tmp;
+	bool ret = false;
+
+	mutex_lock(&proxy->proxy_lock);
+	HASH_ITER(sh, proxy->subproxies, subproxy, tmp) {
+		if (subproxy->alive) {
+			ret = true;
+			break;
+		}
+	}
+	mutex_unlock(&proxy->proxy_lock);
+
+	return ret;
+}
+
 /* For receiving messages from the upstream proxy, also responsible for setting
  * up the connection and testing it's alive. */
 static void *proxy_recv(void *arg)
@@ -1793,7 +1835,7 @@ static void *proxy_recv(void *arg)
 	}
 
 	if (proxy_alive(ckp, si, proxi, cs, false, epfd)) {
-		send_proc(ckp->generator, "reconnect");
+		reconnect_generator(ckp);
 		LOGWARNING("Proxy %d:%s connection established",
 			   proxi->id, proxi->si->url);
 	}
@@ -1806,20 +1848,25 @@ static void *proxy_recv(void *arg)
 		time_t now;
 		int ret;
 
-		while (!proxy_alive(ckp, si, proxi, proxi->cs, true, epfd)) {
-			if (alive) {
-				alive = false;
-				send_proc(ckp->generator, "reconnect");
+		if (!proxi->alive) {
+			while (!subproxies_alive(proxi)) {
+				reconnect_proxy(proxi);
+				if (alive) {
+					LOGWARNING("Proxy %d:%s failed, attempting reconnect",
+						   proxi->id, proxi->si->url);
+					alive = false;
+					reconnect_generator(ckp);
+				}
+				sleep(5);
+				proxi->reconnect_time = time(NULL);
 			}
-			sleep(5);
-			proxi->reconnect_time = time(NULL);
 		}
 		/* Wait 30 seconds before declaring this upstream pool alive
 		 * to prevent switching to unstable pools. */
 		if (!alive && (!current_proxy(gdata) || time(NULL) - proxi->reconnect_time > 30)) {
 			LOGWARNING("Proxy %d:%s recovered", proxi->id, proxi->si->url);
 			proxi->reconnect_time = 0;
-			send_proc(ckp->generator, "reconnect");
+			reconnect_generator(ckp);
 			alive = true;
 		}
 
@@ -1855,13 +1902,11 @@ static void *proxy_recv(void *arg)
 			ret = read_socket_line(cs, 5);
 		}
 		if (ret < 1) {
-			if (parent_proxy(subproxy)) {
-				proxi->reconnect_time = time(NULL);
-				alive = false;
-				LOGWARNING("Proxy %d:%s failed to epoll/read_socket_line in proxy_recv, attempting reconnect",
-					   subproxy->id, subproxy->si->url);
-				send_proc(ckp->generator, "reconnect");
-			}
+			subproxy->alive = false;
+			if (!parent_proxy(subproxy))
+				recruit_subproxy(proxi);
+			LOGNOTICE("Proxy %d:%d %s failed to epoll/read_socket_line in proxy_recv, attempting reconnect",
+				  proxi->id, subproxy->subid, subproxy->si->url);
 			continue;
 		}
 		if (parse_method(ckp, subproxy, cs->buf)) {
@@ -1872,7 +1917,7 @@ static void *proxy_recv(void *arg)
 				subproxy->alive = false;
 				disable_subproxy(gdata, proxi, subproxy);
 				if (parent_proxy(subproxy)) {
-					send_proc(ckp->generator, "reconnect");
+					reconnect_generator(ckp);
 					LOGWARNING("Proxy %d:%s reconnect issue, dropping existing connection",
 						subproxy->id, subproxy->si->url);
 					break;
@@ -1933,7 +1978,7 @@ static proxy_instance_t *wait_best_proxy(ckpool_t *ckp, gdata_t *gdata)
 
 		mutex_lock(&gdata->lock);
 		HASH_ITER(hh, gdata->proxies, proxi, tmp) {
-			if (proxi->alive) {
+			if (proxi->alive || subproxies_alive(proxi)) {
 				if (!ret || proxi->id < ret->id)
 					ret = proxi;
 			}
@@ -1989,14 +2034,6 @@ retry:
 		}
 	} while (selret < 1);
 
-	if (unlikely(proxi->cs->fd < 0)) {
-		LOGWARNING("Upstream proxy %d:%s socket invalidated, will attempt failover",
-			   proxi->id, proxi->cs->url);
-		proxi->alive = false;
-		proxi = NULL;
-		goto reconnect;
-	}
-
 	sockd = accept(us->sockd, NULL, NULL);
 	if (sockd < 0) {
 		LOGEMERG("Failed to accept on proxy socket");
@@ -2160,7 +2197,7 @@ static void server_watchdog(ckpool_t *ckp, server_instance_t *cursi)
 			break;
 	}
 	if (alive)
-		send_proc(ckp->generator, "reconnect");
+		reconnect_generator(ckp);
 }
 
 int generator(proc_instance_t *pi)