Update subscriptions and notifications for proxies that aren't the current proxy for faster switching

src/generator.c

@@ -129,6 +129,7 @@ struct proxy_instance {
 struct generator_data {
 	pthread_mutex_t lock; /* Lock protecting linked lists */
 	proxy_instance_t *proxies; /* Hash list of all proxies */
+	proxy_instance_t *proxy; /* Current proxy */
 	int proxy_notify_id;	// Globally increasing notify id
 	ckmsgq_t *srvchk;	// Server check message queue
 };
@@ -1366,6 +1367,18 @@ static void passthrough_add_send(proxy_instance_t *proxi, const char *msg)
 	ckmsgq_add(proxi->passsends, pm);
 }
 
+static int current_proxy_id(gdata_t *gdata)
+{
+	int ret = 0;
+
+	mutex_lock(&gdata->lock);
+	if (gdata->proxy)
+		ret = gdata->proxy->id;
+	mutex_unlock(&gdata->lock);
+
+	return ret;
+}
+
 static bool proxy_alive(ckpool_t *ckp, server_instance_t *si, proxy_instance_t *proxi,
 			connsock_t *cs, bool pinging)
 {
@@ -1414,8 +1427,19 @@ out:
 	if (!ret) {
 		/* Close and invalidate the file handle */
 		Close(cs->fd);
-	} else
+	} else {
 		keep_sockalive(cs->fd);
+		/* If this isn't a new higher priority proxy we won't be
+		 * issuing a reconnect so tell the stratifier to get the
+		 * subscription and notification data without reconnecting. */
+		if (proxi->id > current_proxy_id(ckp->data)) {
+			char *msg;
+
+			ASPRINTF(&msg, "subscribe=%d", proxi->id);
+			send_proc(ckp->stratifier, msg);
+			free(msg);
+		}
+	}
 	return ret;
 }
 
@@ -1605,6 +1629,7 @@ static proxy_instance_t *current_proxy(ckpool_t *ckp, gdata_t *gdata)
 	while (42) {
 		if (!ping_main(ckp))
 			break;
+		mutex_lock(&gdata->lock);
 		HASH_ITER(hh, gdata->proxies, proxi, tmp) {
 			if (proxi->alive) {
 				if (!ret) {
@@ -1615,6 +1640,8 @@ static proxy_instance_t *current_proxy(ckpool_t *ckp, gdata_t *gdata)
 					ret = proxi;
 			}
 		}
+		gdata->proxy = ret;
+		mutex_unlock(&gdata->lock);
 		if (ret)
 			break;
 		sleep(1);

src/stratifier.c

@@ -1039,6 +1039,8 @@ static void update_subscribe(ckpool_t *ckp, const char *cmd)
 		return;
 	}
 
+	LOGNOTICE("Got updated subscribe for proxy %d", id);
+
 	proxy = proxy_by_id(sdata, id);
 	json_get_bool(&reconnect, val, "reconnect");
 
@@ -1121,12 +1123,13 @@ static void _update_notify(ckpool_t *ckp, const int id)
 		LOGWARNING("Failed to get notify from generator in update_notify");
 		return;
 	}
+	LOGDEBUG("Update notify: %s", buf);
 	if (unlikely(!safecmp(buf, "notready"))) {
 		LOGNOTICE("Generator not ready to send notify to stratifier");
 		return;
 	}
 
-	LOGDEBUG("Update notify: %s", buf);
+	LOGINFO("Got updated notify for proxy %d", id);
 	wb = ckzalloc(sizeof(workbase_t));
 	val = json_loads(buf, 0, NULL);
 	dealloc(buf);