Optimization on connections reset

Limit the size of the queue #1185
Reuse the same user #1186

include/MySQL_Thread.h

@@ -392,6 +392,7 @@ class MySQL_Threads_Handler
 		uint16_t server_capabilities;
 		int poll_timeout;
 		int poll_timeout_on_failure;
+		int connpoll_reset_queue_length;
 		char *eventslog_filename;
 		int eventslog_filesize;
 		// SSL related, proxy to server

lib/MySQL_HostGroups_Manager.cpp

@@ -76,7 +76,17 @@ static void * HGCU_thread_run() {
 			myconn->reset();
 			myconn=(MySQL_Connection *)conn_array->index(i);
 			if (myconn->mysql->net.vio && myconn->mysql->net.fd && myconn->mysql->net.buff) {
-				statuses[i]=mysql_change_user_start(&ret[i], myconn->mysql, myconn->userinfo->username, myconn->userinfo->password, myconn->userinfo->schemaname);
+				MySQL_Connection_userinfo *userinfo = myconn->userinfo;
+				char *auth_password = NULL;
+				if (userinfo->password) {
+					if (userinfo->password[0]=='*') { // we don't have the real password, let's pass sha1
+						auth_password=userinfo->sha1_pass;
+					} else {
+						auth_password=userinfo->password;
+					}
+				}
+				//async_exit_status = mysql_change_user_start(&ret_bool,mysql,_ui->username, auth_password, _ui->schemaname);
+				statuses[i]=mysql_change_user_start(&ret[i], myconn->mysql, myconn->userinfo->username, auth_password, myconn->userinfo->schemaname);
 				if (myconn->mysql->net.vio==NULL || myconn->mysql->net.fd==0 || myconn->mysql->net.buff==NULL) {
 					statuses[i]=0; ret[i]=1;
 				}
@@ -1405,11 +1415,11 @@ MySQL_Connection * MySQL_HostGroups_Manager::get_MyConn_from_pool(unsigned int _
 void MySQL_HostGroups_Manager::destroy_MyConn_from_pool(MySQL_Connection *c) {
 	bool to_del=true; // the default, legacy behavior
 	MySrvC *mysrvc=(MySrvC *)c->parent;
-	if (mysrvc->status==MYSQL_SERVER_STATUS_ONLINE && c->send_quit && queue.size() < 100) {
+	if (mysrvc->status==MYSQL_SERVER_STATUS_ONLINE && c->send_quit && queue.size() < __sync_fetch_and_add(&GloMTH->variables.connpoll_reset_queue_length,0)) {
 		// overall, the backend seems healthy and so it is the connection. Try to reset it
 		proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Trying to reset MySQL_Connection %p, server %s:%d\n", c, mysrvc->address, mysrvc->port);
 		to_del=false;
-		c->userinfo->set(mysql_thread___monitor_username,mysql_thread___monitor_password,mysql_thread___default_schema,NULL);
+		//c->userinfo->set(mysql_thread___monitor_username,mysql_thread___monitor_password,mysql_thread___default_schema,NULL);
 		queue.add(c);
 	} else {
 		// we lock only this part of the code because we need to remove the connection from ConnectionsUsed

lib/MySQL_Thread.cpp

@@ -283,6 +283,7 @@ static char * mysql_thread_variables_names[]= {
 	(char *)"init_connect",
 	(char *)"default_sql_mode",
 	(char *)"default_time_zone",
+	(char *)"connpoll_reset_queue_length",
 	(char *)"stats_time_backend_query",
 	(char *)"stats_time_query_processor",
 	NULL
@@ -383,6 +384,7 @@ MySQL_Threads_Handler::MySQL_Threads_Handler() {
 	variables.autocommit_false_not_reusable=false;
 	variables.query_digests=true;
 	variables.query_digests_lowercase=false;
+	variables.connpoll_reset_queue_length = 50;
 	variables.stats_time_backend_query=true;
 	variables.stats_time_query_processor=true;
 	variables.sessions_sort=true;
@@ -628,6 +630,7 @@ int MySQL_Threads_Handler::get_variable_int(char *name) {
 	if (!strcasecmp(name,"commands_stats")) return (int)variables.commands_stats;
 	if (!strcasecmp(name,"query_digests")) return (int)variables.query_digests;
 	if (!strcasecmp(name,"query_digests_lowercase")) return (int)variables.query_digests_lowercase;
+	if (!strcasecmp(name,"connpoll_reset_queue_length")) return (int)variables.connpoll_reset_queue_length;
 	if (!strcasecmp(name,"stats_time_backend_query")) return (int)variables.stats_time_backend_query;
 	if (!strcasecmp(name,"stats_time_query_processor")) return (int)variables.stats_time_query_processor;
 	if (!strcasecmp(name,"sessions_sort")) return (int)variables.sessions_sort;
@@ -791,6 +794,10 @@ char * MySQL_Threads_Handler::get_variable(char *name) {	// this is the public f
 		sprintf(intbuf,"%d",variables.shun_on_failures);
 		return strdup(intbuf);
 	}
+	if (!strcasecmp(name,"connpoll_reset_queue_length")) {
+		sprintf(intbuf,"%d",variables.connpoll_reset_queue_length);
+		return strdup(intbuf);
+	}
 	if (!strcasecmp(name,"shun_recovery_time_sec")) {
 		sprintf(intbuf,"%d",variables.shun_recovery_time_sec);
 		return strdup(intbuf);
@@ -1649,6 +1656,15 @@ bool MySQL_Threads_Handler::set_variable(char *name, char *value) {	// this is t
 			return false;
 		}
 	}
+	if (!strcasecmp(name,"connpoll_reset_queue_length")) {
+		int intv=atoi(value);
+		if (intv >= 0 && intv <= 1000) {
+			variables.connpoll_reset_queue_length=intv;
+			return true;
+		} else {
+			return false;
+		}
+	}
 	if (!strcasecmp(name,"default_charset")) {
 		if (vallen) {
 			CHARSET_INFO * c=proxysql_find_charset_name(value);