Recruit extra user subproxies when there aren't enough

src/generator.c

@@ -1779,12 +1779,19 @@ static void recruit_subproxies(proxy_instance_t *proxi, const int recruits)
 }
 
 /* Queue up to the requested amount */
-static void recruit_subproxy(proxy_instance_t *proxi, const char *buf)
+static void recruit_subproxy(gdata_t *gdata, const char *buf)
 {
-	int recruits = 1;
+	int recruits = 1, id = 0;
+	proxy_instance_t *proxy;
 
-	sscanf(buf, "recruit=%d", &recruits);
-	recruit_subproxies(proxi, recruits);
+	sscanf(buf, "recruit=%d:%d", &id, &recruits);
+	proxy = proxy_by_id(gdata, id);
+	if (unlikely(!proxy)) {
+		LOGNOTICE("Generator failed to find proxy id %d to recruit subproxies",
+			  id);
+		return;
+	}
+	recruit_subproxies(proxy, recruits);
 }
 
 static void *proxy_reconnect(void *arg)
@@ -2442,7 +2449,7 @@ retry:
 		LOGDEBUG("Proxy received ping request");
 		send_unix_msg(sockd, "pong");
 	} else if (cmdmatch(buf, "recruit")) {
-		recruit_subproxy(proxi, buf);
+		recruit_subproxy(gdata, buf);
 	} else if (cmdmatch(buf, "dropproxy")) {
 		drop_proxy(gdata, buf);
 	} else {

src/stratifier.c

@@ -1295,15 +1295,17 @@ out_unlock:
 	return headroom;
 }
 
-static int64_t userproxy_headroom(sdata_t *sdata, const int userid)
+static int64_t proxy_headroom(sdata_t *sdata, const int userid)
 {
 	proxy_t *proxy, *subproxy, *tmp, *subtmp;
 	int64_t headroom = 0;
 
 	mutex_lock(&sdata->proxy_lock);
 	HASH_ITER(hh, sdata->proxies, proxy, tmp) {
-		if (proxy->userid != userid)
+		if (proxy->userid < userid)
 			continue;
+		if (proxy->userid > userid)
+			break;
 		HASH_ITER(sh, proxy->subproxies, subproxy, subtmp) {
 			if (subproxy->dead)
 				continue;
@@ -1317,11 +1319,11 @@ static int64_t userproxy_headroom(sdata_t *sdata, const int userid)
 
 static void reconnect_client(sdata_t *sdata, stratum_instance_t *client);
 
-static void generator_recruit(const ckpool_t *ckp, const int recruits)
+static void generator_recruit(const ckpool_t *ckp, const int proxyid, const int recruits)
 {
 	char buf[256];
 
-	sprintf(buf, "recruit=%d", recruits);
+	sprintf(buf, "recruit=%d:%d", proxyid, recruits);
 	LOGINFO("Stratifer requesting %d more proxies from generator", recruits);
 	send_generator(ckp, buf, GEN_PRIORITY);
 }
@@ -1365,7 +1367,7 @@ static void reconnect_clients(sdata_t *sdata)
 			  proxy->id);
 	}
 	if (headroom < 0)
-		generator_recruit(sdata->ckp, -headroom);
+		generator_recruit(sdata->ckp, proxy->id, -headroom);
 }
 
 static bool __subproxies_alive(proxy_t *proxy)
@@ -1414,8 +1416,8 @@ static void check_bestproxy(sdata_t *sdata)
 
 static void dead_proxyid(sdata_t *sdata, const int id, const int subid)
 {
+	int reconnects = 0, hard = 0, proxyid = 0;
 	stratum_instance_t *client, *tmp;
-	int reconnects = 0, hard = 0;
 	int64_t headroom;
 	proxy_t *proxy;
 
@@ -1427,6 +1429,8 @@ static void dead_proxyid(sdata_t *sdata, const int id, const int subid)
 	}
 	LOGINFO("Stratifier dropping clients from proxy %d:%d", id, subid);
 	headroom = current_headroom(sdata, &proxy);
+	if (proxy)
+		proxyid = proxy->id;
 
 	ck_rlock(&sdata->instance_lock);
 	HASH_ITER(hh, sdata->stratum_instances, client, tmp) {
@@ -1445,8 +1449,10 @@ static void dead_proxyid(sdata_t *sdata, const int id, const int subid)
 		LOGNOTICE("%d clients flagged to reconnect from dead proxy %d:%d", reconnects,
 			  id, subid);
 	}
+	/* When a proxy dies, recruit more of the global proxies for them to
+	 * fail over to in case user proxies are unavailable. */
 	if (headroom < 0)
-		generator_recruit(sdata->ckp, -headroom);
+		generator_recruit(sdata->ckp, proxyid, -headroom);
 }
 
 static void update_subscribe(ckpool_t *ckp, const char *cmd)
@@ -1544,17 +1550,38 @@ static void update_subscribe(ckpool_t *ckp, const char *cmd)
 	json_decref(val);
 }
 
+/* Find the highest priority alive proxy belonging to userid and recruit extra
+ * subproxies. */
+static void recruit_best_userproxy(sdata_t *sdata, const int userid, const int recruits)
+{
+	proxy_t *proxy, *subproxy, *tmp, *subtmp, *best = NULL;
+
+	mutex_lock(&sdata->proxy_lock);
+	HASH_ITER(hh, sdata->proxies, proxy, tmp) {
+		if (proxy->userid < userid)
+			continue;
+		if (proxy->userid > userid)
+			break;
+		HASH_ITER(sh, proxy->subproxies, subproxy, subtmp) {
+			if (subproxy->dead)
+				continue;
+			best = proxy;
+		}
+	}
+	mutex_unlock(&sdata->proxy_lock);
+
+	if (best)
+		generator_recruit(sdata->ckp, proxy->id, recruits);
+}
+
 /* Check how much headroom the userid proxies have and reconnect any clients
  * that are not bound to it */
 static void check_userproxies(sdata_t *sdata, const int userid)
 {
-	int64_t headroom = userproxy_headroom(sdata, userid);
+	int64_t headroom = proxy_headroom(sdata, userid);
 	stratum_instance_t *client, *tmpclient;
 	int reconnects = 0, hard = 0;
 
-	if (!headroom)
-		return;
-
 	ck_rlock(&sdata->instance_lock);
 	HASH_ITER(hh, sdata->stratum_instances, client, tmpclient) {
 		if (client->user_id != userid)
@@ -1576,7 +1603,8 @@ static void check_userproxies(sdata_t *sdata, const int userid)
 		LOGNOTICE("%d clients flagged for reconnect to user %d proxies",
 			  reconnects, userid);
 	}
-	/* FIXME: Recruit extra user proxies when headroom < 0 */
+	if (headroom < 0)
+		recruit_best_userproxy(sdata, userid, -headroom);
 }
 
 static void update_notify(ckpool_t *ckp, const char *cmd)
@@ -2386,7 +2414,7 @@ static void lazy_reconnect_client(sdata_t *sdata, stratum_instance_t *client)
 		LOGNOTICE("Reconnecting client %"PRId64, client->id);
 		reconnect_client(sdata, client);
 	} else {
-		generator_recruit(sdata->ckp, -headroom);
+		generator_recruit(sdata->ckp, proxy->id, -headroom);
 		if (!client->reconnect) {
 			LOGNOTICE("Flagging client %"PRId64, client->id);
 			client->reconnect = true;
@@ -2823,8 +2851,12 @@ static sdata_t *select_sdata(const ckpool_t *ckp, sdata_t *ckp_sdata, const int
 		LOGWARNING("Temporarily insufficient subproxies to accept more clients");
 		return NULL;
 	}
-	if (best->id != current->id || current->headroom < 2)
-		generator_recruit(ckp, 1);
+	if (best->global && (best->id != current->id || current->headroom < 2))
+		generator_recruit(ckp, current->id, 1);
+	else if (userid) {
+		if (proxy_headroom(ckp_sdata, userid) < 2)
+			generator_recruit(ckp, best->id, 1);
+	}
 	return best->sdata;
 }
 
@@ -3494,7 +3526,7 @@ static json_t *parse_authorise(stratum_instance_t *client, const json_t *params_
 			if (client->sdata && client->sdata->proxy && client->sdata->proxy->global) {
 				sdata_t *ckp_sdata = ckp->data;
 
-				if (userproxy_headroom(ckp_sdata, client->user_id))
+				if (proxy_headroom(ckp_sdata, client->user_id))
 					client->reconnect = true;
 			}
 		} else {