From 27e0ccd6415d572382bea2fef500265b9ce73cdd Mon Sep 17 00:00:00 2001
From: Mark Riddoch <Mark.Riddoch@skysql.com>
Date: Thu, 11 Sep 2014 11:03:53 +0100
Subject: [PATCH] Fix for bug 447 - Error log flooded with same warnings if
 there are no slaves present

---
 server/modules/include/readwritesplit.h       |  4 +++
 .../routing/readwritesplit/readwritesplit.c   | 34 +++++++++++++++----
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/server/modules/include/readwritesplit.h b/server/modules/include/readwritesplit.h
index 6fc639005..15d190ddb 100644
--- a/server/modules/include/readwritesplit.h
+++ b/server/modules/include/readwritesplit.h
@@ -71,6 +71,7 @@ typedef enum backend_type_t {
         BE_COUNT
 } backend_type_t;
 
+struct router_instance;
 typedef struct rses_property_st rses_property_t;
 typedef struct router_client_session ROUTER_CLIENT_SES;
 
@@ -261,6 +262,7 @@ struct router_client_session {
 #if defined(PREP_STMT_CACHING)
         HASHTABLE*       rses_prep_stmt[2];
 #endif
+	struct router_instance	 *router;	/*< The router instance */
         struct router_client_session* next;
 #if defined(SS_DEBUG)
         skygw_chk_t      rses_chk_tail;
@@ -294,6 +296,8 @@ typedef struct router_instance {
 	unsigned int	        bitvalue;    /*< Required value of server->status   */
 	ROUTER_STATS            stats;       /*< Statistics for this router         */
         struct router_instance* next;        /*< Next router on the list            */
+	bool			available_slaves;
+					    /*< The router has some slaves avialable */
 } ROUTER_INSTANCE;
 
 #define BACKEND_TYPE(b) (SERVER_IS_MASTER((b)->backend_server) ? BE_MASTER :    \
diff --git a/server/modules/routing/readwritesplit/readwritesplit.c b/server/modules/routing/readwritesplit/readwritesplit.c
index 1c22d4979..79c26c0f6 100644
--- a/server/modules/routing/readwritesplit/readwritesplit.c
+++ b/server/modules/routing/readwritesplit/readwritesplit.c
@@ -484,6 +484,11 @@ createInstance(SERVICE *service, char **options)
         }
         router->servers[nservers] = NULL;
 
+	/*
+	 * Until we know otherwise assume we have some available slaves.
+	 */
+	router->available_slaves = true;
+
 	/*
 	 * If server weighting has been defined calculate the percentage
 	 * of load that will be sent to each server. This is only used for
@@ -636,6 +641,8 @@ static void* newSession(
         client_rses->rses_chk_top = CHK_NUM_ROUTER_SES;
         client_rses->rses_chk_tail = CHK_NUM_ROUTER_SES;
 #endif
+
+	client_rses->router = router;
         /** 
          * If service config has been changed, reload config from service to 
          * router instance first.
@@ -972,15 +979,30 @@ static bool get_dcb(
 					(master_host && (backend_ref->bref_backend->backend_server == master_host->backend_server)) &&
 					smallest_nconn == -1);
                                 
-                                LOGIF(LE, (skygw_log_write_flush(
-                                        LOGFILE_ERROR,
-                                        "Warning : No slaves connected nor "
-                                        "available. Choosing master %s:%d "
-                                        "instead.",
+				if (rses->router->available_slaves)
+				{
+					rses->router->available_slaves = false;
+	                                LOGIF(LE, (skygw_log_write_flush(
+                                        	LOGFILE_ERROR,
+                                        	"Warning : No slaves avialable "
+                                        	"for the service %s. "
+						"Using master %s:%d "
+                                        	"instead.",
+					rses->router->service->name,
                                         backend_ref->bref_backend->backend_server->name,
                                         backend_ref->bref_backend->backend_server->port)));
+				}
                         }
-                }                        
+                }
+		else if (rses->router->available_slaves == false)
+		{
+			rses->router->available_slaves = true;
+			LOGIF(LE, (skygw_log_write_flush(
+				LOGFILE_ERROR,
+				"At least one slave has become avilable for "
+				"the service %s.",
+					rses->router->service->name)));
+		}
                 ss_dassert(succp);
         }
         else if (btype == BE_MASTER)