Related to MAX-95, added code which makes it possible to change max_slave_connections parameter value during run time of MaxScale. The change will be effective in rwsplit sessions created after the configuration modification and reload. Note that in order to config modification to be effective, the user must connect the debug interface of MaxScale (telnet) and execute 'reload config'.

In practice, 'reload config' reads config file and updates config parameters of rwsplit router service. In addition to that there is a version number indicating what generation of configuration service holds. When router instance is created (when MaxScale is started) service's config version is copied to router intance. Whenever new client connection (rwsplit session) is started, router instance's config version is checked against that of service's. If versions differ, service's config data is copied to router instance. New session will be started with router instance's config values.

server/modules/include/readwritesplit.h

@@ -191,6 +191,7 @@ typedef struct router_instance {
 	BACKEND**               servers;     /*< Backend servers                    */
 	BACKEND*                master;      /*< NULL or pointer                    */
 	rwsplit_config_t        rwsplit_config; /*< expanded config info from SERVICE */
+	int                     rwsplit_version;/*< version number for router's config */
         unsigned int	        bitmask;     /*< Bitmask to apply to server->status */
 	unsigned int	        bitvalue;    /*< Required value of server->status   */
 	ROUTER_STATS            stats;       /*< Statistics for this router         */