Merge pull request #401 from prymitive/cheaper_fix_limit

adapted cheaper algos to work properly with cheaper limits

core/master_utils.c

@@ -151,7 +151,13 @@ int uwsgi_calc_cheaper(void) {
 		uwsgi.cheaper_fifo_delta = 0;
 	}
 
-	if (!ignore_algo) needed_workers = uwsgi.cheaper_algo();
+	// if cheaper limits wants to change worker count, then skip cheaper algo
+	if (!needed_workers) needed_workers = uwsgi.cheaper_algo(!ignore_algo);
+	// safe check to verify if cheaper algo obeyed ignore_algo value
+	if (ignore_algo && needed_workers > 0) {
+		uwsgi_log("BUG! cheaper algo returned %d but it cannot spawn any worker at this time!\n", needed_workers);
+		needed_workers = 0;
+	}
 
 	if (needed_workers > 0) {
 		for (i = 1; i <= uwsgi.numproc; i++) {
@@ -189,7 +195,7 @@ int uwsgi_calc_cheaper(void) {
 }
 
 // fake algo to allow control with the fifo
-int uwsgi_cheaper_algo_manual(void) {
+int uwsgi_cheaper_algo_manual(int can_spawn) {
 	return 0;
 }
 
@@ -228,7 +234,7 @@ int uwsgi_cheaper_algo_manual(void) {
 */
 
 
-int uwsgi_cheaper_algo_spare(void) {
+int uwsgi_cheaper_algo_spare(int can_spawn) {
 
 	int i;
 	static uint64_t overload_count = 0;
@@ -252,7 +258,7 @@ int uwsgi_cheaper_algo_spare(void) {
 healthy:
 
 	// are we overloaded ?
-	if (overload_count > uwsgi.cheaper_overload) {
+	if (can_spawn && overload_count > uwsgi.cheaper_overload) {
 
 #ifdef UWSGI_DEBUG
 		uwsgi_log("overloaded !!!\n");
@@ -320,7 +326,7 @@ healthy:
 
 */
 
-int uwsgi_cheaper_algo_backlog(void) {
+int uwsgi_cheaper_algo_backlog(int can_spawn) {
 
 	int i;
 #ifdef __linux__
@@ -329,7 +335,7 @@ int uwsgi_cheaper_algo_backlog(void) {
 	int backlog = 0;
 #endif
 
-	if (backlog > (int) uwsgi.cheaper_overload) {
+	if (can_spawn && backlog > (int) uwsgi.cheaper_overload) {
 		// activate the first available worker (taking step into account)
 		int decheaped = 0;
 		// search for cheaped workers
@@ -1345,7 +1351,7 @@ end:
 	return NULL;
 }
 
-void uwsgi_register_cheaper_algo(char *name, int (*func) (void)) {
+void uwsgi_register_cheaper_algo(char *name, int (*func) (int)) {
 
 	struct uwsgi_cheaper_algo *uca = uwsgi.cheaper_algos;
 

plugins/cheaper_busyness/cheaper_busyness.c

@@ -142,7 +142,7 @@ int spawn_emergency_worker(int backlog) {
 #endif
 
 
-int cheaper_busyness_algo(void) {
+int cheaper_busyness_algo(int can_spawn) {
 
 	int i;
 	// we use microseconds
@@ -243,11 +243,12 @@ int cheaper_busyness_algo(void) {
 			uwsgi_cheaper_busyness_global.tolerance_counter = 0;
 
 			int decheaped = 0;
-			for (i = 1; i <= uwsgi.numproc; i++) {
-				
-				if (uwsgi.workers[i].cheaped == 1 && uwsgi.workers[i].pid == 0) {
-					decheaped++;
-					if (decheaped >= uwsgi.cheaper_step) break;
+			if (can_spawn) {
+				for (i = 1; i <= uwsgi.numproc; i++) {
+					if (uwsgi.workers[i].cheaped == 1 && uwsgi.workers[i].pid == 0) {
+						decheaped++;
+						if (decheaped >= uwsgi.cheaper_step) break;
+					}
 				}
 			}
 
@@ -271,15 +272,15 @@ int cheaper_busyness_algo(void) {
 				uwsgi_log("[busyness] %llus average busyness is at %llu%%, will spawn %d new worker(s)\n",
 					uwsgi.cheaper_overload, avg_busyness, decheaped);
 			} else {
-				uwsgi_log("[busyness] %llus average busyness is at %llu%% but we already started maximum number of workers (%d)\n",
-					uwsgi.cheaper_overload, avg_busyness, uwsgi.numproc);
+				uwsgi_log("[busyness] %llus average busyness is at %llu%% but we already started maximum number of workers available with current limits (%d)\n",
+					uwsgi.cheaper_overload, avg_busyness, active_workers);
 			}
 
 			// return the maximum number of workers to spawn
 			return decheaped;
 
 #ifdef __linux__
-		} else if (backlog > uwsgi_cheaper_busyness_global.backlog_alert && active_workers < uwsgi.numproc) {
+		} else if (can_spawn && backlog > uwsgi_cheaper_busyness_global.backlog_alert && active_workers < uwsgi.numproc) {
 			return spawn_emergency_worker(backlog);
 #endif
 
@@ -347,14 +348,14 @@ int cheaper_busyness_algo(void) {
 	}
 
 #ifdef __linux__
-	else if (backlog > uwsgi_cheaper_busyness_global.backlog_alert && active_workers < uwsgi.numproc) {
+	else if (can_spawn && backlog > uwsgi_cheaper_busyness_global.backlog_alert && active_workers < uwsgi.numproc) {
 		// we check for backlog overload every cycle
 		return spawn_emergency_worker(backlog);
 	}
 	else if (backlog > 0) {
 		if (uwsgi_cheaper_busyness_global.backlog_is_nonzero) {
 			// backlog was > 0 last time, check timestamp and spawn workers if needed
-			if ((now - uwsgi_cheaper_busyness_global.backlog_nonzero_since)/1000000 >= uwsgi_cheaper_busyness_global.backlog_nonzero_alert) {
+			if (can_spawn && (now - uwsgi_cheaper_busyness_global.backlog_nonzero_since)/1000000 >= uwsgi_cheaper_busyness_global.backlog_nonzero_alert) {
 				uwsgi_log("[busyness] backlog was non-zero for %llu second(s), spawning new worker(s)\n", (now - uwsgi_cheaper_busyness_global.backlog_nonzero_since)/1000000);
 				uwsgi_cheaper_busyness_global.backlog_nonzero_since = now;
 				return spawn_emergency_worker(backlog);
@@ -391,4 +392,3 @@ struct uwsgi_plugin cheaper_busyness_plugin = {
 	.options = uwsgi_cheaper_busyness_options,
 	
 };
-

uwsgi.h

@@ -1563,7 +1563,7 @@ struct uwsgi_signal_rb_timer {
 struct uwsgi_cheaper_algo {
 
 	char *name;
-	int (*func) (void);
+	int (*func) (int);
 	struct uwsgi_cheaper_algo *next;
 };
 
@@ -1735,7 +1735,7 @@ struct uwsgi_server {
 	int cheaper;
 	char *requested_cheaper_algo;
 	struct uwsgi_cheaper_algo *cheaper_algos;
-	int (*cheaper_algo) (void);
+	int (*cheaper_algo) (int);
 	int cheaper_step;
 	uint64_t cheaper_overload;
 	// minimal number of running workers in cheaper mode
@@ -3612,16 +3612,16 @@ void uwsgi_manage_zerg(int, int, int *);
 time_t uwsgi_now(void);
 
 int uwsgi_calc_cheaper(void);
-int uwsgi_cheaper_algo_spare(void);
-int uwsgi_cheaper_algo_backlog(void);
-int uwsgi_cheaper_algo_backlog2(void);
-int uwsgi_cheaper_algo_manual(void);
+int uwsgi_cheaper_algo_spare(int);
+int uwsgi_cheaper_algo_backlog(int);
+int uwsgi_cheaper_algo_backlog2(int);
+int uwsgi_cheaper_algo_manual(int);
 
 int uwsgi_master_log(void);
 int uwsgi_master_req_log(void);
 void uwsgi_flush_logs(void);
 
-void uwsgi_register_cheaper_algo(char *, int (*)(void));
+void uwsgi_register_cheaper_algo(char *, int (*)(int));
 
 void uwsgi_setup_locking(void);
 int uwsgi_fcntl_lock(int);