Add configuration capabilities for persistent connections.

server/include/dcb.h

@@ -335,6 +335,7 @@ int		dcb_remove_callback(DCB *, DCB_REASON, int (*)(struct dcb *, DCB_REASON, vo
 			 void *);
 int		dcb_isvalid(DCB *);			/* Check the DCB is in the linked list */
 int		dcb_count_by_usage(DCB_USAGE);		/* Return counts of DCBs */
+int             dcb_persistent_clean_count(DCB *);      /* Clean persistent and return count */
 
 bool   dcb_set_state(DCB* dcb, dcb_state_t new_state, dcb_state_t* old_state);
 void   dcb_call_foreach (struct server* server, DCB_REASON reason);

server/include/server.h

@@ -97,6 +97,8 @@ typedef struct server {
 	bool            master_err_is_logged; /*< If node failed, this indicates whether it is logged */
         DCB             *persistent;    /**< List of unused persistent connections to the server */
         SPINLOCK        persistlock;   /**< Lock for adjusting the persistent connections list */
+        long            persistpoolmax; /**< Maximum size of persistent connections pool */
+        long            persistmaxtime; /**< Maximum number of seconds connection can live */
 } SERVER;
 
 /**