diff --git a/core/init.c b/core/init.c
index 4a661ef1..9fb10d72 100644
--- a/core/init.c
+++ b/core/init.c
@@ -90,6 +90,9 @@ void uwsgi_init_default() {
 	uwsgi.cores = 1;
 	uwsgi.threads = 1;
 
+	// default max number of rpc slot
+	uwsgi.max_rpc = 64;
+
 	uwsgi.offload_threads_events = 64;
 
 	uwsgi.default_app = -1;
diff --git a/core/rpc.c b/core/rpc.c
index 893593ee..78b1e285 100644
--- a/core/rpc.c
+++ b/core/rpc.c
@@ -14,8 +14,8 @@ int uwsgi_register_rpc(char *name, uint8_t modifier1, uint8_t args, void *func)
 
 	uwsgi_lock(uwsgi.rpc_table_lock);
 
-	if (uwsgi.shared->rpc_count < MAX_RPC) {
-		urpc = &uwsgi.shared->rpc_table[uwsgi.shared->rpc_count];
+	if (uwsgi.shared->rpc_count < uwsgi.rpc_max) {
+		urpc = &uwsgi.rpc_table[uwsgi.shared->rpc_count];
 
 		memcpy(urpc->name, name, strlen(name));
 		urpc->modifier1 = modifier1;
@@ -36,13 +36,13 @@ int uwsgi_register_rpc(char *name, uint8_t modifier1, uint8_t args, void *func)
 uint16_t uwsgi_rpc(char *name, uint8_t argc, char *argv[], uint16_t argvs[], char *output) {
 
 	struct uwsgi_rpc *urpc = NULL;
-	int i;
+	uint64_t i;
 	uint16_t ret = 0;
 
 	for (i = 0; i < uwsgi.shared->rpc_count; i++) {
-		if (uwsgi.shared->rpc_table[i].name[0] != 0) {
-			if (!strcmp(uwsgi.shared->rpc_table[i].name, name)) {
-				urpc = &uwsgi.shared->rpc_table[i];
+		if (uwsgi.rpc_table[i].name[0] != 0) {
+			if (!strcmp(uwsgi.rpc_table[i].name, name)) {
+				urpc = &uwsgi.rpc_table[i];
 				break;
 			}
 		}
diff --git a/plugins/lua/lua_plugin.c b/plugins/lua/lua_plugin.c
index 0774a73d..b5c9377c 100644
--- a/plugins/lua/lua_plugin.c
+++ b/plugins/lua/lua_plugin.c
@@ -14,7 +14,7 @@ struct uwsgi_lua {
 
 #define lca(L, n)		ulua_check_args(L, __FUNCTION__, n)
 
-struct uwsgi_option uwsgi_lua_options[] = {
+static struct uwsgi_option uwsgi_lua_options[] = {
 
 	{"lua", required_argument, 0, "load lua wsapi app", uwsgi_opt_set_str, &ulua.filename, 0},
 
@@ -24,7 +24,7 @@ struct uwsgi_option uwsgi_lua_options[] = {
 
 static void ulua_check_args(lua_State *L, const char *func, int n) {
 	int args = lua_gettop(L);
-	char error[4096];
+	char error[1024];
 	if (args != n) {
 		if (n == 1) {
 			snprintf(error, 4096, "uwsgi.%s takes 1 parameter", func+10);
@@ -82,53 +82,6 @@ static int uwsgi_api_register_rpc(lua_State *L) {
 	return 1;
 }
 
-
-
-static char *encode_lua_table(lua_State *L, int index, uint16_t *size) {
-
-	char *buf, *ptrbuf;
-	char *key;
-	char *value;
-	size_t keylen;
-	size_t vallen;
-
-	*size = 0;
-
-	lua_pushnil(L);
-	while (lua_next(L, index) != 0) {
-		if (lua_isstring(L, -2) && lua_isstring(L, -1)) {
-			key = (char *) lua_tolstring(L, -2, &keylen);
-			value = (char *) lua_tolstring(L, -1, &vallen);
-			if (keylen > 0xffff || vallen > 0xffff) continue;
-			*size += (2+keylen+2+vallen);
-		}
-		lua_pop(L, 1);
-	}
-
-	buf = uwsgi_malloc(*size);
-
-	ptrbuf = buf;
-	lua_pushnil(L);
-	while (lua_next(L, index) != 0) {
-		if (lua_isstring(L, -2) && lua_isstring(L, -1)) {
-			key = (char *) lua_tolstring(L, -2, &keylen);
-			value = (char *) lua_tolstring(L, -1, &vallen);
-
-			if (keylen > 0xffff || vallen > 0xffff) continue;
-
-			*ptrbuf++ = (uint8_t) (keylen  & 0xff);
-                        *ptrbuf++ = (uint8_t) ((keylen >>8) & 0xff);
-			memcpy(ptrbuf, key, keylen); ptrbuf += keylen;
-			*ptrbuf++ = (uint8_t) (vallen  & 0xff);
-                        *ptrbuf++ = (uint8_t) ((vallen >>8) & 0xff);
-			memcpy(ptrbuf, value, vallen); ptrbuf += vallen;
-		}
-		lua_pop(L, 1);
-	}
-
-	return buf;
-}
-
 static int uwsgi_api_cache_set(lua_State *L) {
 
 	int args = lua_gettop(L);
@@ -137,6 +90,8 @@ static int uwsgi_api_cache_set(lua_State *L) {
         uint64_t expires = 0;
 	size_t vallen;
 
+	if (!uwsgi.caches) goto error;
+
 
 	if (args > 1) {
 
@@ -146,10 +101,13 @@ static int uwsgi_api_cache_set(lua_State *L) {
 			expires = lua_tonumber(L, 3);
 		}
 
+		uwsgi_wlock(uwsgi.caches->lock);
         	uwsgi_cache_set((char *)key, strlen(key), (char *)value, (uint16_t) vallen, expires, 0);
-		
+		uwsgi_rwunlock(uwsgi.caches->lock);
 	}
 
+error:
+
 	lua_pushnil(L);
 	return 1;
 
@@ -185,94 +143,30 @@ static int uwsgi_api_cache_get(lua_State *L) {
 
         lca(L, 1);
 
+	if (!uwsgi.caches) goto error;
+
 	if (lua_isstring(L, 1)) {
-
+		// get the key
 		key = lua_tolstring(L, 1, NULL);
+		uwsgi_rlock(uwsgi.caches->lock);
         	value = uwsgi_cache_get((char *)key, strlen(key), &valsize);
-
         	if (value) {
                 	lua_pushlstring(L, value, valsize);
+			uwsgi_rwunlock(uwsgi.caches->lock);
 			return 1;
         	}
+		uwsgi_rwunlock(uwsgi.caches->lock);
 
 	}
 
+error:
+
 	lua_pushnil(L);
 
         return 1;
 
 }
 
-
-static int uwsgi_api_send_message(lua_State *L) {
-
-	int args = lua_gettop(L);
-	const char *host;
-	int uwsgi_fd;
-	uint8_t modifier1, modifier2;
-	char *pkt = NULL;
-	uint16_t pktsize = 0 ;
-	char buf[4096];
-	int rlen;
-	int items = 0;
-	int input_fd = -1, timeout = -1, input_size = 0;
-	
-	// is this an fd ?
-	if (lua_isnumber(L, 1)) {
-		args = 1;
-	}
-	else if (lua_isstring(L, 1)) {
-		host = lua_tolstring(L, 1, NULL);	
-		uwsgi_fd = uwsgi_connect((char *)host, timeout, 0);
-		modifier1 = lua_tonumber(L, 2);	
-		modifier2 = lua_tonumber(L, 3);	
-		if (args > 4) {
-			timeout = lua_tonumber(L, 5);
-			if (args == 7) {
-				input_fd = lua_tonumber(L, 6);	
-				input_size = lua_tonumber(L, 7);	
-			}
-		}
-		if (lua_istable(L,4)) {
-			// passed a table
-			pkt = encode_lua_table(L, 4, &pktsize);
-		}
-	 	if (uwsgi_send_message(uwsgi_fd, modifier1, modifier2, pkt, pktsize, input_fd, input_size, timeout) == -1) {
-			free(pkt);
-			lua_pushnil(L);
-			return 1;
-		}
-		free(pkt);
-
-		for(;;) {
-        		rlen = uwsgi_waitfd(uwsgi_fd, timeout);
-        		if (rlen > 0) {
-                		rlen = read(uwsgi_fd, buf, 4096);
-                		if (rlen < 0) {
-                        		uwsgi_error("read()");
-					break;
-                		}
-                		else if (rlen > 0) {
-					lua_pushlstring(L, buf, rlen);	
-					items++;
-                		}
-				else {
-					break;
-				}
-			}
-        		else if (rlen == 0) {
-                		uwsgi_log("uwsgi request timed out waiting for response\n");
-				break;
-        		}
-		}
-
-                close(uwsgi_fd);
-
-	}
-	
-	return items;
-}
-
 static int uwsgi_api_cl(lua_State *L) {
 
 	struct wsgi_request *wsgi_req = current_wsgi_req();
@@ -338,9 +232,7 @@ static int uwsgi_api_unlock(lua_State *L) {
 
 static const luaL_reg uwsgi_api[] = {
   {"log", uwsgi_api_log},
-  {"cl", uwsgi_api_cl},
-  {"req_fd", uwsgi_api_req_fd},
-  {"send_message", uwsgi_api_send_message},
+  {"connection_fd", uwsgi_api_req_fd},
   {"cache_get", uwsgi_api_cache_get},
   {"cache_set", uwsgi_api_cache_set},
   {"register_signal", uwsgi_api_register_signal},
@@ -374,9 +266,9 @@ static int uwsgi_lua_input(lua_State *L) {
 	return 0;
 }
 
-int uwsgi_lua_init(){
+static int uwsgi_lua_init(){
 
-	uwsgi_log("Initializing Lua environment... (%d cores)\n", uwsgi.cores);
+	uwsgi_log("Initializing Lua environment... (%d lua_States)\n", uwsgi.cores);
 
 	ulua.L = uwsgi_malloc( sizeof(lua_State*) * uwsgi.cores );
 
@@ -386,7 +278,7 @@ int uwsgi_lua_init(){
 
 }
 
-void uwsgi_lua_app() {
+static void uwsgi_lua_app() {
 	int i;
 
 	if (ulua.filename) {
@@ -423,7 +315,7 @@ void uwsgi_lua_app() {
 	}
 }
 
-int uwsgi_lua_request(struct wsgi_request *wsgi_req) {
+static int uwsgi_lua_request(struct wsgi_request *wsgi_req) {
 
 	int i;
 	const char *http, *http2;
@@ -538,13 +430,13 @@ clear:
 
 }
 
-void uwsgi_lua_after_request(struct wsgi_request *wsgi_req) {
+static void uwsgi_lua_after_request(struct wsgi_request *wsgi_req) {
 
 	log_request(wsgi_req);
 }
 
 
-int uwsgi_lua_magic(char *mountpoint, char *lazy) {
+static int uwsgi_lua_magic(char *mountpoint, char *lazy) {
 
 	if (!strcmp(lazy+strlen(lazy)-4, ".lua")) {
                 ulua.filename = lazy;
@@ -559,7 +451,7 @@ int uwsgi_lua_magic(char *mountpoint, char *lazy) {
 	return 0;
 }
 
-char *uwsgi_lua_code_string(char *id, char *code, char *func, char *key, uint16_t keylen) {
+static char *uwsgi_lua_code_string(char *id, char *code, char *func, char *key, uint16_t keylen) {
 
 	static struct lua_State *L = NULL;
 
@@ -607,13 +499,15 @@ char *uwsgi_lua_code_string(char *id, char *code, char *func, char *key, uint16_
         return NULL;
 }
 
-int uwsgi_lua_signal_handler(uint8_t sig, void *handler) {
+static int uwsgi_lua_signal_handler(uint8_t sig, void *handler) {
 
 	struct wsgi_request *wsgi_req = current_wsgi_req();
 	
 	lua_State *L = ulua.L[wsgi_req->async_id];
 
+#ifdef UWSGI_DEBUG
 	uwsgi_log("managing signal handler on core %d\n", wsgi_req->async_id);
+#endif
 
 	lua_rawgeti(L, LUA_REGISTRYINDEX, (long) handler);
 
@@ -631,7 +525,7 @@ int uwsgi_lua_signal_handler(uint8_t sig, void *handler) {
 	
 }
 
-uint16_t uwsgi_lua_rpc(void * func, uint8_t argc, char **argv, uint16_t argvs[], char *buffer) {
+static uint16_t uwsgi_lua_rpc(void * func, uint8_t argc, char **argv, uint16_t argvs[], char *buffer) {
 
         uint8_t i;
         const char *sv;
@@ -643,7 +537,9 @@ uint16_t uwsgi_lua_rpc(void * func, uint8_t argc, char **argv, uint16_t argvs[],
 	
 	lua_State *L = ulua.L[wsgi_req->async_id];
 
+#ifdef UWSGI_DEBUG
 	uwsgi_log("get function %d\n", ifunc);
+#endif
 	lua_rawgeti(L, LUA_REGISTRYINDEX, ifunc);
 
         for(i=0;i<argc;i++) {
@@ -658,7 +554,9 @@ uint16_t uwsgi_lua_rpc(void * func, uint8_t argc, char **argv, uint16_t argvs[],
 	
 	sv = lua_tolstring(L, -1, &sl);
 
+#ifdef UWSGI_DEBUG
 	uwsgi_log("sv = %s sl = %lu\n", sv, (unsigned long) sl);
+#endif
 	if (sl <= 0xffff) {
 		memcpy(buffer, sv, sl);
 		return sl;
diff --git a/plugins/psgi/uwsgi_plmodule.c b/plugins/psgi/uwsgi_plmodule.c
index bdc78644..a59d5607 100644
--- a/plugins/psgi/uwsgi_plmodule.c
+++ b/plugins/psgi/uwsgi_plmodule.c
@@ -100,7 +100,7 @@ XS(XS_cache_set) {
 	STRLEN keylen;
 	STRLEN vallen;
 
-	if (uwsgi.cache_max_items == 0) goto clear;
+	if (!uwsgi.caches) goto clear;
 	
 	psgi_check_args(2);
 
@@ -122,7 +122,7 @@ XS(XS_cache_get) {
 	STRLEN keylen;
 	uint64_t vallen;
 
-	if (uwsgi.cache_max_items == 0) goto clear;
+	if (!uwsgi.caches) goto clear;
 	
 	psgi_check_args(1);
 
diff --git a/plugins/python/uwsgi_pymodule.c b/plugins/python/uwsgi_pymodule.c
index 4459b9e0..5b9bb3ab 100644
--- a/plugins/python/uwsgi_pymodule.c
+++ b/plugins/python/uwsgi_pymodule.c
@@ -334,12 +334,12 @@ PyObject *py_uwsgi_call(PyObject * self, PyObject * args) {
 
 PyObject *py_uwsgi_rpc_list(PyObject * self, PyObject * args) {
 
-	int i;
+	uint64_t i;
 	PyObject *rpc_list = PyTuple_New(uwsgi.shared->rpc_count);
 
 	for (i = 0; i < uwsgi.shared->rpc_count; i++) {
-		if (uwsgi.shared->rpc_table[i].name[0] != 0) {
-			PyTuple_SetItem(rpc_list, i, PyString_FromString(uwsgi.shared->rpc_table[i].name));
+		if (uwsgi.rpc_table[i].name[0] != 0) {
+			PyTuple_SetItem(rpc_list, i, PyString_FromString(uwsgi.rpc_table[i].name));
 		}
 	}
 
diff --git a/plugins/rpc/rpc_plugin.c b/plugins/rpc/rpc_plugin.c
index e9877010..c592c101 100644
--- a/plugins/rpc/rpc_plugin.c
+++ b/plugins/rpc/rpc_plugin.c
@@ -5,13 +5,16 @@ extern struct uwsgi_server uwsgi;
 
 int uwsgi_rpc_request(struct wsgi_request *wsgi_req) {
 
+	// this is the list of args
 	char *argv[256];
+	// this is the size of each argument
 	uint16_t argvs[256];
+	// maximum number of supported arguments
 	uint8_t argc = 0xff;
 
 	/* Standard RPC request */
         if (!wsgi_req->uh->pktsize) {
-                uwsgi_log("Invalid RPC request. skip.\n");
+                uwsgi_log("Empty RPC request. skip.\n");
                 return -1;
         }
 
@@ -34,11 +37,16 @@ int uwsgi_rpc_request(struct wsgi_request *wsgi_req) {
 	uwsgi_log("RPC args %d\n", argc-1);
 #endif
 	
+	// call the function (output will be in wsgi_req->buffer)
 	wsgi_req->uh->pktsize = uwsgi_rpc(argv[0], argc-1, argv+1, argvs+1, wsgi_req->buffer);
 
+	// using modifier1 we may want a raw output
 	if (wsgi_req->uh->modifier2 == 0) {
-		uwsgi_response_write_body_do(wsgi_req, (char *) wsgi_req->uh, 4);
+		if (uwsgi_response_write_body_do(wsgi_req, (char *) wsgi_req->uh, 4)) {
+			return -1;
+		}
 	}
+	// write the response
 	uwsgi_response_write_body_do(wsgi_req, wsgi_req->buffer, wsgi_req->uh->pktsize);
 	
 	return 0;
diff --git a/uwsgi.h b/uwsgi.h
index 18af0408..618db088 100644
--- a/uwsgi.h
+++ b/uwsgi.h
@@ -2122,6 +2122,10 @@ struct uwsgi_server {
 		struct uwsgi_lock_item *rpc_table_lock;
 		struct uwsgi_lock_item *sa_lock;
 
+		// rpc
+		uint64_t rpc_max;
+		struct uwsgi_rpc *rpc_table;	
+
 		// subscription client
 		int subscribe_freq;
 		int subscription_tolerance;
@@ -2258,8 +2262,7 @@ struct uwsgi_server {
 		struct uwsgi_signal_rb_timer rb_timers[MAX_TIMERS];
 		int rb_timers_cnt;
 
-		struct uwsgi_rpc rpc_table[MAX_RPC];
-		int rpc_count;
+		uint64_t rpc_count;
 
 		int worker_log_pipe[2];
 		// used for request logging
@@ -2669,9 +2672,9 @@ void uwsgi_cache_start_sync_servers(void);
 
 	int uwsgi_start(void *);
 
-	int uwsgi_register_rpc(char *, uint8_t, uint8_t, void *);
-	uint16_t uwsgi_rpc(char *, uint8_t, char **, uint16_t *, char *);
-	char *uwsgi_do_rpc(char *, char *, uint8_t, char **, uint16_t *, uint16_t *);
+int uwsgi_register_rpc(char *, uint8_t, uint8_t, void *);
+uint16_t uwsgi_rpc(char *, uint8_t, char **, uint16_t *, char *);
+char *uwsgi_do_rpc(char *, char *, uint8_t, char **, uint16_t *, uint16_t *);
 
 	char *uwsgi_cheap_string(char *, int);