diff --git a/include/configfile.hpp b/include/configfile.hpp
index 071f9ea95..06cbd0bbf 100644
--- a/include/configfile.hpp
+++ b/include/configfile.hpp
@@ -8,7 +8,7 @@ using namespace libconfig;
 
 class ProxySQL_ConfigFile {
   private:
-  struct stat statbuf;
+  //struct stat statbuf;
   char *filename;
   public:
   Config *cfg;
diff --git a/lib/MySQL_HostGroups_Manager.cpp b/lib/MySQL_HostGroups_Manager.cpp
index 51085949a..529d30363 100644
--- a/lib/MySQL_HostGroups_Manager.cpp
+++ b/lib/MySQL_HostGroups_Manager.cpp
@@ -135,7 +135,7 @@ void connect_cb(EV_P_ ev_io *w, int revents) {
 		if ((getsockopt(w->fd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) ||
 			(optval != 0)) {
 			/* Connection failed; try the next address in the list. */
-			int errnum = optval ? optval : errno;
+			//int errnum = optval ? optval : errno;
 			ev_io_stop(MyHGM->gtid_ev_loop, w);
 			close(w->fd);
 			MyHGM->gtid_missing_nodes = true;
@@ -170,7 +170,7 @@ void connect_cb(EV_P_ ev_io *w, int revents) {
 }
 
 struct ev_io * new_connector(char *address, uint16_t gtid_port, uint16_t mysql_port) {
-	struct sockaddr_in a;
+	//struct sockaddr_in a;
 	int s;
 
 	if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
@@ -4321,7 +4321,7 @@ SQLite3_result * MySQL_HostGroups_Manager::get_stats_mysql_gtid_executed() {
 			//sprintf(buf,"%d", mysrvc->port);
 			string s1 = gtid_executed_to_string(gtid_si->gtid_executed);
 			pta[2]=strdup(s1.c_str());
-			sprintf(buf,"%llu", (int)gtid_si->events_read);
+			sprintf(buf,"%llu", gtid_si->events_read);
 			pta[3]=strdup(buf);
 		} else {
 			std::string s = it->first;
diff --git a/lib/MySQL_Monitor.cpp b/lib/MySQL_Monitor.cpp
index 4f3019e86..9c4575d5e 100644
--- a/lib/MySQL_Monitor.cpp
+++ b/lib/MySQL_Monitor.cpp
@@ -62,7 +62,9 @@ class ConsumerThread : public Thread {
 		// Remove 1 item at a time and process it. Blocks if no items are 
 		// available to process.
 		for (int i = 0; ( thrn ? i < thrn : 1) ; i++) {
+VALGRIND_DISABLE_ERROR_REPORTING;
 			WorkItem* item = (WorkItem*)m_queue.remove();
+VALGRIND_ENABLE_ERROR_REPORTING;
 			if (item==NULL) {
 				if (thrn) {
 					// we took a NULL item that wasn't meant to reach here! Add it again
diff --git a/lib/MySQL_PreparedStatement.cpp b/lib/MySQL_PreparedStatement.cpp
index 818179128..8f913559a 100644
--- a/lib/MySQL_PreparedStatement.cpp
+++ b/lib/MySQL_PreparedStatement.cpp
@@ -729,7 +729,7 @@ bool MySQL_STMTs_local_v14::client_close(uint32_t client_statement_id) {
 		uint64_t global_stmt_id = s->second;
 		client_stmt_to_global_ids.erase(s);
 		GloMyStmt->ref_count_client(global_stmt_id, -1);
-		auto s2 = global_stmt_to_client_ids.find(global_stmt_id);
+		//auto s2 = global_stmt_to_client_ids.find(global_stmt_id);
 		std::pair<std::multimap<uint64_t,uint32_t>::iterator, std::multimap<uint64_t,uint32_t>::iterator> ret;
 		ret = global_stmt_to_client_ids.equal_range(global_stmt_id);
 		for (std::multimap<uint64_t,uint32_t>::iterator it=ret.first; it!=ret.second; ++it) {
@@ -816,12 +816,14 @@ MySQL_STMT_Global_info *MySQL_STMT_Manager_v14::add_prepared_statement(
 void MySQL_STMT_Manager_v14::get_metrics(uint64_t *c_unique, uint64_t *c_total,
                              uint64_t *stmt_max_stmt_id, uint64_t *cached,
                              uint64_t *s_unique, uint64_t *s_total) {
+#ifdef DEBUG
 	uint64_t c_u = 0;
 	uint64_t c_t = 0;
 	uint64_t m = 0;
 	uint64_t c = 0;
 	uint64_t s_u = 0;
 	uint64_t s_t = 0;
+#endif
 	pthread_rwlock_wrlock(&rwlock_);
 	statuses.cached = map_stmt_id_to_info.size();
 	statuses.c_unique = statuses.cached - num_stmt_with_ref_client_count_zero;
@@ -897,7 +899,7 @@ class PS_global_stats {
 	char **get_row() {
 		char buf[128];
 		char **pta=(char **)malloc(sizeof(char *)*8);
-		sprintf(buf,"%llu",statement_id);
+		sprintf(buf,"%lu",statement_id);
 		pta[0]=strdup(buf);
 		sprintf(buf,"%u",hid);
 		pta[1]=strdup(buf);
diff --git a/lib/MySQL_Protocol.cpp b/lib/MySQL_Protocol.cpp
index 1e1f7ecca..7e0dee0f8 100644
--- a/lib/MySQL_Protocol.cpp
+++ b/lib/MySQL_Protocol.cpp
@@ -1273,7 +1273,7 @@ bool MySQL_Protocol::process_pkt_COM_CHANGE_USER(unsigned char *pkt, unsigned in
 	mysql_hdr hdr;
 	memcpy(&hdr,pkt,sizeof(mysql_hdr));
 	int default_hostgroup=-1;
-	bool transaction_persistent;
+	bool transaction_persistent = true;
 	bool _ret_use_ssl=false;
 	cur++;
 	user=pkt+cur;
diff --git a/lib/MySQL_Session.cpp b/lib/MySQL_Session.cpp
index 320cf6584..76940bc46 100644
--- a/lib/MySQL_Session.cpp
+++ b/lib/MySQL_Session.cpp
@@ -596,29 +596,30 @@ bool MySQL_Session::handler_CommitRollback(PtrSize_t *pkt) {
 // FIXME: This function is currently disabled . See #469
 bool MySQL_Session::handler_SetAutocommit(PtrSize_t *pkt) {
 	size_t sal=strlen("set autocommit");
+	char * _ptr = (char *)pkt->ptr;
 	if ( pkt->size >= 7+sal) {
 		if (strncasecmp((char *)"SET @@session.autocommit",(char *)pkt->ptr+5,strlen((char *)"SET @@session.autocommit"))==0) {
-			memmove(pkt->ptr+9, pkt->ptr+19, pkt->size - 19);
-			memset(pkt->ptr+pkt->size-10,' ',10);
+			memmove(_ptr+9, _ptr+19, pkt->size - 19);
+			memset(_ptr+pkt->size-10,' ',10);
 		}
 		if (strncasecmp((char *)"set autocommit",(char *)pkt->ptr+5,sal)==0) {
 			void *p = NULL;
 			for (int i=5+sal; i<pkt->size; i++) {
 				*((char *)pkt->ptr+i) = tolower(*((char *)pkt->ptr+i));
 			}
-			p = memmem(pkt->ptr+5+sal, pkt->size-5-sal, (void *)"false", 5);
+			p = memmem(_ptr+5+sal, pkt->size-5-sal, (void *)"false", 5);
 			if (p) {
 				memcpy(p,(void *)"0    ",5);
 			}
-			p = memmem(pkt->ptr+5+sal, pkt->size-5-sal, (void *)"true", 4);
+			p = memmem(_ptr+5+sal, pkt->size-5-sal, (void *)"true", 4);
 			if (p) {
 				memcpy(p,(void *)"1   ",4);
 			}
-			p = memmem(pkt->ptr+5+sal, pkt->size-5-sal, (void *)"off", 3);
+			p = memmem(_ptr+5+sal, pkt->size-5-sal, (void *)"off", 3);
 			if (p) {
 				memcpy(p,(void *)"0  ",3);
 			}
-			p = memmem(pkt->ptr+5+sal, pkt->size-5-sal, (void *)"on", 2);
+			p = memmem(_ptr+5+sal, pkt->size-5-sal, (void *)"on", 2);
 			if (p) {
 				memcpy(p,(void *)"1 ",2);
 			}
@@ -4211,7 +4212,7 @@ bool MySQL_Session::handler___status_WAITING_CLIENT_DATA___STATE_SLEEP___MYSQL_C
 		char buf2[32];
 		sprintf(buf,"%u",thread_session_id);
 		int l0=strlen("CONNECTION_ID()");
-		memcpy(buf2,pkt->ptr+5+SELECT_CONNECTION_ID_LEN-l0,l0);
+		memcpy(buf2,(char *)pkt->ptr+5+SELECT_CONNECTION_ID_LEN-l0,l0);
 		buf2[l0]=0;
 		unsigned int nTrx=NumActiveTransactions();
 		uint16_t setStatus = (nTrx ? SERVER_STATUS_IN_TRANS : 0 );
@@ -4273,7 +4274,7 @@ bool MySQL_Session::handler___status_WAITING_CLIENT_DATA___STATE_SLEEP___MYSQL_C
 				sprintf(buf,"%llu",last_insert_id);
 				char buf2[32];
 				int l0=strlen("LAST_INSERT_ID()");
-				memcpy(buf2,pkt->ptr+5+SELECT_LAST_INSERT_ID_LEN-l0,l0);
+				memcpy(buf2,(char *)pkt->ptr+5+SELECT_LAST_INSERT_ID_LEN-l0,l0);
 				buf2[l0]=0;
 				unsigned int nTrx=NumActiveTransactions();
 				uint16_t setStatus = (nTrx ? SERVER_STATUS_IN_TRANS : 0 );
diff --git a/lib/ProxySQL_Admin.cpp b/lib/ProxySQL_Admin.cpp
index 740df3398..952df3675 100644
--- a/lib/ProxySQL_Admin.cpp
+++ b/lib/ProxySQL_Admin.cpp
@@ -2428,7 +2428,7 @@ void admin_session_handler(MySQL_Session *sess, void *_pa, PtrSize_t *pkt) {
 	ProxySQL_Admin *pa=(ProxySQL_Admin *)_pa;
 	char *error=NULL;
 	int cols;
-	int affected_rows;
+	int affected_rows = 0;
 	bool run_query=true;
 	SQLite3_result *resultset=NULL;
 	char *strA=NULL;
@@ -2460,7 +2460,7 @@ void admin_session_handler(MySQL_Session *sess, void *_pa, PtrSize_t *pkt) {
 	// handle special queries from Cluster
 	// for bug #1188 , ProxySQL Admin needs to know the exact query
 	if (!strncasecmp(CLUSTER_QUERY_MYSQL_SERVERS, query_no_space, strlen(CLUSTER_QUERY_MYSQL_SERVERS))) {
-		ProxySQL_Admin *SPA=(ProxySQL_Admin *)pa;
+		//ProxySQL_Admin *SPA=(ProxySQL_Admin *)pa;
 		if (sess->session_type == PROXYSQL_SESSION_ADMIN) { // no stats
 			resultset=MyHGM->dump_table_mysql_servers();
 			if (resultset) {
@@ -2472,7 +2472,7 @@ void admin_session_handler(MySQL_Session *sess, void *_pa, PtrSize_t *pkt) {
 		}
 	}
 	if (!strncasecmp(CLUSTER_QUERY_MYSQL_REPLICATION_HOSTGROUPS, query_no_space, strlen(CLUSTER_QUERY_MYSQL_REPLICATION_HOSTGROUPS))) {
-		ProxySQL_Admin *SPA=(ProxySQL_Admin *)pa;
+		//ProxySQL_Admin *SPA=(ProxySQL_Admin *)pa;
 		if (sess->session_type == PROXYSQL_SESSION_ADMIN) { // no stats
 			resultset=MyHGM->dump_table_mysql_replication_hostgroups();
 			if (resultset) {
@@ -2570,7 +2570,7 @@ void admin_session_handler(MySQL_Session *sess, void *_pa, PtrSize_t *pkt) {
 		if ((query_no_space_length == strlen("SELECT GLOBAL_CHECKSUM()")) && (!strncasecmp("SELECT GLOBAL_CHECKSUM()", query_no_space, strlen("SELECT GLOBAL_CHECKSUM()")))) {
 			char buf[32];
 			pthread_mutex_lock(&GloVars.checksum_mutex);
-			sprintf(buf,"%llu",GloVars.checksums_values.global_checksum);
+			sprintf(buf,"%lu",GloVars.checksums_values.global_checksum);
 			pthread_mutex_unlock(&GloVars.checksum_mutex);
 			uint16_t setStatus = 0;
 			MySQL_Data_Stream *myds=sess->client_myds;
@@ -4545,9 +4545,7 @@ void ProxySQL_Admin::flush_mysql_variables___runtime_to_database(SQLite3DB *db,
 
 void ProxySQL_Admin::flush_ldap_variables___database_to_runtime(SQLite3DB *db, bool replace) {
 	proxy_debug(PROXY_DEBUG_ADMIN, 4, "Flushing LDAP variables. Replace:%d\n", replace);
-	if (
-		( GloMyLdapAuth == NULL )
-	) {
+	if (GloMyLdapAuth == NULL) {
 		return;
 	}
 	char *error=NULL;
@@ -5062,10 +5060,10 @@ bool ProxySQL_Admin::set_variable(char *name, char *value) {  // this is the pub
 			if ((variables.mysql_ifaces==NULL) || strcasecmp(variables.mysql_ifaces,value) ) update_creds=true;
 			if (variables.mysql_ifaces)
 				free(variables.mysql_ifaces);
-				variables.mysql_ifaces=strdup(value);
-				if (update_creds && variables.mysql_ifaces) {
-					S_amll.update_ifaces(variables.mysql_ifaces, &S_amll.ifaces_mysql);
-				}
+			variables.mysql_ifaces=strdup(value);
+			if (update_creds && variables.mysql_ifaces) {
+				S_amll.update_ifaces(variables.mysql_ifaces, &S_amll.ifaces_mysql);
+			}
 			return true;
 		} else {
 			return false;
@@ -5234,56 +5232,60 @@ bool ProxySQL_Admin::set_variable(char *name, char *value) {  // this is the pub
 		}
 	}
 	if (!strcasecmp(name,"cluster_mysql_query_rules_save_to_disk")) {
+		bool rt = false;
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
 			variables.cluster_mysql_query_rules_save_to_disk=true;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_query_rules_save_to_disk, true);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_query_rules_save_to_disk, true);
 			return true;
 		}
 		if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
 			variables.cluster_mysql_query_rules_save_to_disk=false;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_query_rules_save_to_disk, false);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_query_rules_save_to_disk, false);
 			return true;
 		}
-		return false;
+		return rt;
 	}
 	if (!strcasecmp(name,"cluster_mysql_servers_save_to_disk")) {
+		bool rt = false;
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
 			variables.cluster_mysql_servers_save_to_disk=true;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_servers_save_to_disk, true);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_servers_save_to_disk, true);
 			return true;
 		}
 		if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
 			variables.cluster_mysql_servers_save_to_disk=false;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_servers_save_to_disk, false);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_servers_save_to_disk, false);
 			return true;
 		}
-		return false;
+		return rt;
 	}
 	if (!strcasecmp(name,"cluster_mysql_users_save_to_disk")) {
+		bool rt = false;
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
 			variables.cluster_mysql_users_save_to_disk=true;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_users_save_to_disk, true);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_users_save_to_disk, true);
 			return true;
 		}
 		if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
 			variables.cluster_mysql_users_save_to_disk=false;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_users_save_to_disk, false);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_mysql_users_save_to_disk, false);
 			return true;
 		}
-		return false;
+		return rt;
 	}
 	if (!strcasecmp(name,"cluster_proxysql_servers_save_to_disk")) {
+		bool rt = false;
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
 			variables.cluster_proxysql_servers_save_to_disk=true;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_proxysql_servers_save_to_disk, true);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_proxysql_servers_save_to_disk, true);
 			return true;
 		}
 		if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
 			variables.cluster_proxysql_servers_save_to_disk=false;
-			__sync_lock_test_and_set(&GloProxyCluster->cluster_proxysql_servers_save_to_disk, false);
+			rt = __sync_lock_test_and_set(&GloProxyCluster->cluster_proxysql_servers_save_to_disk, false);
 			return true;
 		}
-		return false;
+		return rt;
 	}
 	if (!strcasecmp(name,"checksum_mysql_query_rules")) {
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
@@ -7280,7 +7282,6 @@ void ProxySQL_Admin::stats___mysql_users() {
 }
 
 void ProxySQL_Admin::stats___mysql_gtid_executed() {
-	int i;
 	statsdb->execute("DELETE FROM stats_mysql_gtid_executed");
 	SQLite3_result *resultset=NULL;
 	resultset = MyHGM->get_stats_mysql_gtid_executed();
diff --git a/lib/c_tokenizer.c b/lib/c_tokenizer.c
index caa52fff2..3efe43c37 100644
--- a/lib/c_tokenizer.c
+++ b/lib/c_tokenizer.c
@@ -487,7 +487,6 @@ char *mysql_query_strip_comments(char *s, int _len) {
 	char *p_r_t = r;
 
 	char prev_char = 0;
-	char qutr_char = 0;
 
 	char flag = 0;
 
diff --git a/lib/mysql_data_stream.cpp b/lib/mysql_data_stream.cpp
index 42bf28fcf..094e75e65 100644
--- a/lib/mysql_data_stream.cpp
+++ b/lib/mysql_data_stream.cpp
@@ -807,7 +807,7 @@ int MySQL_Data_Stream::buffer2array() {
 					PSarrayIN->add(queueIN.pkt.ptr,queueIN.pkt.size);
 				} else {
 					// we append the packet at the end of the previous packet
-					memcpy(last_pkt->ptr+last_pkt->size, queue_r_ptr(queueIN) , queueIN.pkt.size);
+					memcpy((char *)last_pkt->ptr+last_pkt->size, queue_r_ptr(queueIN) , queueIN.pkt.size);
 					last_pkt->size += queueIN.pkt.size;
 					queue_r(queueIN, queueIN.pkt.size);