diff --git a/server/core/hashtable.c b/server/core/hashtable.c
index 762869434..1997b55ec 100644
--- a/server/core/hashtable.c
+++ b/server/core/hashtable.c
@@ -180,6 +180,7 @@ HASHENTRIES	*entry, *ptr;
 	}
 	free(table->entries);
 	
+	hashtable_write_unlock(table);
 	if (!table->ht_isflat)
 	{
 		free(table);
@@ -498,7 +499,7 @@ hashtable_read_lock(HASHTABLE *table)
 			;
 		spinlock_acquire(&table->spin);
 	}
-	table->n_readers++;
+	atomic_add(&table->n_readers, 1);
 	spinlock_release(&table->spin);
 }
 
diff --git a/server/core/service.c b/server/core/service.c
index 116db12ae..c0cc6930e 100644
--- a/server/core/service.c
+++ b/server/core/service.c
@@ -1089,8 +1089,8 @@ int service_refresh_users(SERVICE *service) {
 	if (! spinlock_acquire_nowait(&service->users_table_spin)) {
 		LOGIF(LD, (skygw_log_write_flush(
 			LOGFILE_DEBUG,
-			"%lu [service_refresh_users] failed to get get lock for loading new users' table: another thread is loading users",
-			pthread_self())));
+			"%s: [service_refresh_users] failed to get get lock for loading new users' table: another thread is loading users",
+			service->name)));
 
 		return 1;
 	}
@@ -1098,12 +1098,12 @@ int service_refresh_users(SERVICE *service) {
 	
 	/* check if refresh rate limit has exceeded */
 	if ( (time(NULL) < (service->rate_limit.last + USERS_REFRESH_TIME)) || (service->rate_limit.nloads > USERS_REFRESH_MAX_PER_TIME)) { 
+		spinlock_release(&service->users_table_spin);
 		LOGIF(LE, (skygw_log_write_flush(
 			LOGFILE_ERROR,
-			"Refresh rate limit exceeded for load of users' table for service '%s'.",
+			"%s: Refresh rate limit exceeded for load of users' table.",
 			service->name)));
 
-		spinlock_release(&service->users_table_spin);
  		return 1;
 	}
 
diff --git a/server/modules/protocol/mysql_client.c b/server/modules/protocol/mysql_client.c
index b99ed8cc6..8191995ff 100644
--- a/server/modules/protocol/mysql_client.c
+++ b/server/modules/protocol/mysql_client.c
@@ -504,6 +504,13 @@ static int gw_mysql_do_authentication(DCB *dcb, GWBUF *queue) {
 					username, 
 					stage1_hash);
 		}
+		else
+		{
+			LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE,
+				"%s: login attempt for user %s, user not "
+				"found.",
+				dcb->service->name, username)));
+		}
 	}
 
 	/* Do again the database check */