From b1065603178587424fe9072f6b26f665e8c09e6f Mon Sep 17 00:00:00 2001
From: VilhoRaatikka <vilho.raatikka@skysql.com>
Date: Wed, 3 Dec 2014 13:27:31 +0200
Subject: [PATCH] Fix to bug # 634, http://bugs.skysql.com/show_bug.cgi?id=634
 COM_SHOW_SLAVE_STAT wasn't classified but it was treated as 'unknown' and
 thus routed to master.

---
 query_classifier/query_classifier.cc          |  1 +
 .../routing/readwritesplit/readwritesplit.c   | 54 ++++++++++---------
 2 files changed, 29 insertions(+), 26 deletions(-)

diff --git a/query_classifier/query_classifier.cc b/query_classifier/query_classifier.cc
index 109269252..4d484310a 100644
--- a/query_classifier/query_classifier.cc
+++ b/query_classifier/query_classifier.cc
@@ -619,6 +619,7 @@ static skygw_query_type_t resolve_query_type(
                         break;
 
                 case SQLCOM_SELECT:
+		case SQLCOM_SHOW_SLAVE_STAT:
                         type |= QUERY_TYPE_READ;
                         break;
 
diff --git a/server/modules/routing/readwritesplit/readwritesplit.c b/server/modules/routing/readwritesplit/readwritesplit.c
index c21ecf26b..b303022af 100644
--- a/server/modules/routing/readwritesplit/readwritesplit.c
+++ b/server/modules/routing/readwritesplit/readwritesplit.c
@@ -1212,25 +1212,27 @@ static bool get_dcb(
 			 * backend and update assign it to new candidate if 
 			 * necessary.
 			 */
-			else if (SERVER_IS_SLAVE(b->backend_server) && 
-				(max_rlag == MAX_RLAG_UNDEFINED ||
+			else if (SERVER_IS_SLAVE(b->backend_server))
+			{
+				if (max_rlag == MAX_RLAG_UNDEFINED ||
 				(b->backend_server->rlag != MAX_RLAG_NOT_AVAILABLE &&
-				b->backend_server->rlag <= max_rlag)))
-			{
-				candidate_bref = check_candidate_bref(
-							candidate_bref,
-							&backend_ref[i],
-							rses->rses_config.rw_slave_select_criteria);
-			}
-			else
-			{
-				LOGIF(LT, (skygw_log_write(
-					LOGFILE_TRACE,
-					"Server %s:%d is too much behind the "
-					"master, %d s. and can't be chosen.",
-					b->backend_server->name,
-					b->backend_server->port,
-					b->backend_server->rlag)));
+				b->backend_server->rlag <= max_rlag))
+				{
+					candidate_bref = check_candidate_bref(
+								candidate_bref,
+								&backend_ref[i],
+								rses->rses_config.rw_slave_select_criteria);
+				}
+				else
+				{
+					LOGIF(LT, (skygw_log_write(
+						LOGFILE_TRACE,
+						"Server %s:%d is too much behind the "
+						"master, %d s. and can't be chosen.",
+						b->backend_server->name,
+						b->backend_server->port,
+						b->backend_server->rlag)));
+				}
 			}
 		} /*<  for */
 		/** Assign selected DCB's pointer value */
@@ -1474,7 +1476,7 @@ static route_target_t get_route_target (
 			QUERY_IS_TYPE(qtype, QUERY_TYPE_UNKNOWN)));
 		target = TARGET_MASTER;
 	}
-#if defined(SS_DEBUG)
+#if defined(SS_EXTRA_DEBUG)
 	LOGIF(LT, (skygw_log_write(
 		LOGFILE_TRACE,
 		"Selected target \"%s\"",
@@ -2132,14 +2134,14 @@ static int routeQuery(
 				rlag_max);
 		if (succp)
 		{
-#if defined(SS_DEBUG)
+#if defined(SS_EXTRA_DEBUG)
 			LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
 						   "Found DCB for slave.")));
+#endif
 			ss_dassert(get_bref_from_dcb(router_cli_ses, target_dcb) != 
 					router_cli_ses->rses_master_ref);
 			ss_dassert(get_root_master_bref(router_cli_ses) == 
 					router_cli_ses->rses_master_ref);
-#endif
 			atomic_add(&inst->stats.n_slave, 1);
 		}
 		else
@@ -2204,7 +2206,7 @@ static int routeQuery(
 
 		LOGIF(LT, (skygw_log_write(
 			LOGFILE_TRACE,
-			"Route query to %s\t%s:%d <",
+			"Route query to %s \t%s:%d <",
 			(SERVER_IS_MASTER(bref->bref_backend->backend_server) ? 
 				"master" : "slave"),
 			bref->bref_backend->backend_server->name,
@@ -3948,12 +3950,12 @@ static bool route_session_write(
 			{
 				LOGIF(LT, (skygw_log_write(
 					LOGFILE_TRACE,
-					"Route query to %s\t%s:%d%s",
+					"Route query to %s \t%s:%d%s",
 					(SERVER_IS_MASTER(backend_ref[i].bref_backend->backend_server) ? 
 						"master" : "slave"),
 					backend_ref[i].bref_backend->backend_server->name,
 					backend_ref[i].bref_backend->backend_server->port,
-					(i+1==router_cli_ses->rses_nbackends ? " <" : ""))));
+					(i+1==router_cli_ses->rses_nbackends ? " <" : " "))));
 			}
 
                         if (BREF_IS_IN_USE((&backend_ref[i])))
@@ -4003,12 +4005,12 @@ static bool route_session_write(
 			{
 				LOGIF(LT, (skygw_log_write(
 					LOGFILE_TRACE,
-					"Route query to %s\t%s:%d%s",
+					"Route query to %s \t%s:%d%s",
 					(SERVER_IS_MASTER(backend_ref[i].bref_backend->backend_server) ? 
 					"master" : "slave"),
 					backend_ref[i].bref_backend->backend_server->name,
 					backend_ref[i].bref_backend->backend_server->port,
-					(i+1==router_cli_ses->rses_nbackends ? " <" : ""))));
+					(i+1==router_cli_ses->rses_nbackends ? " <" : " "))));
 			}
 			
                         scur = backend_ref_get_sescmd_cursor(&backend_ref[i]);