Added support for disabling the saving of the session command history for the schemarouter.

server/modules/include/schemarouter.h

@@ -136,6 +136,7 @@ typedef struct mysql_sescmd_st {
         GWBUF*             my_sescmd_buf;        /*< Query buffer */
         unsigned char      my_sescmd_packet_type;/*< Packet type */
 	bool               my_sescmd_is_replied; /*< Is cmd replied to client */
+        int      position; /*< Position of this command */
 #if defined(SS_DEBUG)
         skygw_chk_t        my_sescmd_chk_tail;
 #endif
@@ -170,6 +171,7 @@ typedef struct sescmd_cursor_st {
 	rses_property_t**  scmd_cur_ptr_property; /*< address of pointer to owner property */
 	mysql_sescmd_t*    scmd_cur_cmd;          /*< pointer to current session command */
 	bool               scmd_cur_active;       /*< true if command is being executed */
+        int      position; /*< Position of this cursor */
 #if defined(SS_DEBUG)
 	skygw_chk_t        scmd_cur_chk_tail;
 #endif
@@ -221,6 +223,7 @@ typedef struct backend_ref_st {
         DCB*            bref_dcb; /*< Backend DCB */
         bref_state_t    bref_state; /*< State of the backend */
         bool            bref_mapped; /*< Whether the backend has been mapped */
+        bool            last_sescmd_replied;
         int             bref_num_result_wait; /*< Number of not yet received results */
         sescmd_cursor_t bref_sescmd_cur; /*< Session command cursor */
 	GWBUF*          bref_pending_cmd; /*< For stmt which can't be routed due active sescmd execution */
@@ -237,6 +240,7 @@ typedef struct schemarouter_config_st {
         int               rw_max_slave_conn_count;
 	target_t          rw_use_sql_variables_in;
         int max_sescmd_hist;
+        bool disable_sescmd_hist;
 } schemarouter_config_t;
 
 /**
@@ -248,6 +252,7 @@ typedef struct {
         int             longest_sescmd; /*< Longest chain of stored session commands */
         int             n_hist_exceeded;/*< Number of sessions that exceeded session
                                          * command history limit */
+        time_t          ses_longest;      /*< Session start time */
 } ROUTER_STATS;
 
 /**
@@ -281,6 +286,7 @@ struct router_client_session {
         DCB*            dcb_reply; /*< Internal DCB used to send replies to the client */
         ROUTER_STATS    stats;     /*< Statistics for this router         */
         int             n_sescmd;
+        int             pos_generator;
 #if defined(SS_DEBUG)
         skygw_chk_t      rses_chk_tail;
 #endif
@@ -303,15 +309,10 @@ typedef struct router_instance {
 	ROUTER_STATS            stats;       /*< Statistics for this router         */
         struct router_instance* next;        /*< Next router on the list            */
 	bool			available_slaves; /*< The router has some slaves available */
-	//HASHTABLE* dbnames_hash; /** Hashtable containing the database names and where to find them */
+
-	//char** ignore_list;
 } ROUTER_INSTANCE;
 
 #define BACKEND_TYPE(b) (SERVER_IS_MASTER((b)->backend_server) ? BE_MASTER :    \
         (SERVER_IS_SLAVE((b)->backend_server) ? BE_SLAVE :  BE_UNDEFINED));
-#if 0
-void* dbnames_hash_init(ROUTER_INSTANCE* inst,BACKEND** backends);
-bool update_dbnames_hash(ROUTER_INSTANCE* inst,BACKEND** backends, HASHTABLE* hashtable);
-#endif
 
 #endif /*< _SCHEMAROUTER_H */

server/modules/routing/schemarouter/schemarouter.c

@@ -721,6 +721,11 @@ createInstance(SERVICE *service, char **options)
         } 
         router->service = service;
 	router->schemarouter_config.max_sescmd_hist = 0;
+	router->stats.longest_sescmd = 0;
+	router->stats.n_hist_exceeded = 0;
+	router->stats.n_queries = 0;
+	router->stats.n_sescmd = 0;
+	router->stats.ses_longest = 0;
         spinlock_init(&router->lock);
         
         /** Calculate number of servers */
@@ -752,6 +757,10 @@ createInstance(SERVICE *service, char **options)
 	    {
 		router->schemarouter_config.max_sescmd_hist = atoi(value);
 	    }
+	    else if(strcmp(options[i],"disable_sescmd_history") == 0)
+	    {
+		router->schemarouter_config.disable_sescmd_hist = config_truth_value(value);
+	    }
 	    else
 	    {
 		skygw_log_write(LOGFILE_ERROR,"Error: Unknown router options for Schemarouter: %s",options[i]);
@@ -1158,14 +1167,15 @@ static void closeSession(
                 dcb_close(router_cli_ses->dcb_reply);
                 dcb_close(router_cli_ses->dcb_route);
 
-
-
                 /** Unlock */
                 rses_end_locked_router_action(router_cli_ses);
 
 		spinlock_acquire(&inst->lock);
 		if(inst->stats.longest_sescmd < router_cli_ses->stats.longest_sescmd)
 		    inst->stats.longest_sescmd = router_cli_ses->stats.longest_sescmd;
+		time_t ses_time = difftime(time(NULL),router_cli_ses->rses_client_dcb->session->stats.connect);
+		if(inst->stats.ses_longest < ses_time)
+		    inst->stats.ses_longest = ses_time;
 		spinlock_release(&inst->lock);
         }
 }
@@ -2342,6 +2352,10 @@ diagnostic(ROUTER *instance, DCB *dcb)
 	    router->stats.longest_sescmd);
     dcb_printf(dcb,"Session command history limit exceeded: %d times\n",
 	    router->stats.n_hist_exceeded);
+
+     dcb_printf(dcb,"\n\33[1;4mSession Time Statistics\33[0m\n");
+     dcb_printf(dcb,"Longest session: %d seconds\n",router->stats.ses_longest);
+     dcb_printf(dcb,"\n");
 }
 
 /**
@@ -3186,7 +3200,7 @@ static mysql_sescmd_t* mysql_sescmd_init (
         /** Set session command buffer */
         sescmd->my_sescmd_buf  = sescmd_buf;
         sescmd->my_sescmd_packet_type = packet_type;
-        
+        sescmd->position = atomic_add(&rses->pos_generator,1);
         return sescmd;
 }
 
@@ -3238,6 +3252,7 @@ static GWBUF* sescmd_cursor_process_replies(
          */
         while (scmd != NULL && replybuf != NULL)
         {
+	    scur->position = scmd->position;
                 /** Faster backend has already responded to client : discard */
                 if (scmd->my_sescmd_is_replied)
                 {
@@ -3805,6 +3820,44 @@ static bool route_session_write(
 
 		goto return_succp;
 	}
+
+	if(router_cli_ses->rses_config.disable_sescmd_hist)
+	{
+	    rses_property_t *prop, *tmp;
+	    backend_ref_t* bref;
+	    bool conflict;
+
+	    prop = router_cli_ses->rses_properties[RSES_PROP_TYPE_SESCMD];
+	    while(prop)
+	    {
+		conflict = false;
+
+		for(i = 0;i<router_cli_ses->rses_nbackends;i++)
+		{
+		    bref = &backend_ref[i];
+		    if(BREF_IS_IN_USE(bref))
+		    {
+
+			if(bref->bref_sescmd_cur.position <= prop->rses_prop_data.sescmd.position)
+			{
+			    conflict = true;
+			    break;
+			}
+		    }
+		}
+
+		if(conflict)
+		{
+		    break;
+		}
+
+		tmp = prop;
+		router_cli_ses->rses_properties[RSES_PROP_TYPE_SESCMD] = prop->rses_prop_next;
+		rses_property_done(tmp);
+		prop = router_cli_ses->rses_properties[RSES_PROP_TYPE_SESCMD];
+	    }
+	}
+
         /**
 	 *
          * Additional reference is created to querybuf to