SAK-24944 Mysql Optimizer bug in forums

This is an issue with the MYSQL Optimizer where a bad plan is cached and performance is greatly affected. It is generally not a good idea to override a DB's optimzer but this issue has created enough problems to warrant its addition.
jayrp11 · Jun 1, 2015 · 0e9be82 · 0e9be82
1 parent 4b6391a
commit 0e9be82
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Showing 3 changed files with 28 additions and 2 deletions.
diff --git a/.../src/java/org/sakaiproject/component/app/messageforums/MessageForumsForumManagerImpl.java b/.../src/java/org/sakaiproject/component/app/messageforums/MessageForumsForumManagerImpl.java
@@ -1496,6 +1496,9 @@ public int getNumModTopicCurrentUserHasModPermForWithPermissionLevel(final List
 
 	        LOG.debug("getNumModTopicCurrentUserHasModPermForWithPermissionLevel executing with membershipItems: " + membershipList);
 
+	        // hibernate will not like an empty list so return 0
+	        if (membershipList.isEmpty()) return 0;
+
 	        HibernateCallback hcb = new HibernateCallback() {
 	            public Object doInHibernate(Session session) throws HibernateException, SQLException {
 	                Query q = session.getNamedQuery(QUERY_GET_NUM_MOD_TOPICS_WITH_MOD_PERM_BY_PERM_LEVEL);
@@ -1517,9 +1520,29 @@ public int getNumModTopicCurrentUserHasModPermForWithPermissionLevelName(final L
 
 	        LOG.debug("getNumModTopicCurrentUserHasModPermForWithPermissionLevelName executing with membershipItems: " + membershipList);
 
+	        // hibernate will not like an empty list so return 0
+	        if (membershipList.isEmpty()) return 0;
+
 	        HibernateCallback hcb = new HibernateCallback() {
 	            public Object doInHibernate(Session session) throws HibernateException, SQLException {
-	                Query q = session.getNamedQuery(QUERY_GET_NUM_MOD_TOPICS_WITH_MOD_PERM_BY_PERM_LEVEL_NAME);
+	            	Query q = null;
+	            	if ("mysql".equals(serverConfigurationService.getString("[email protected]"))) {
+	                    q = session.createSQLQuery("select straight_join count(*) as NBR " +
+		                		"from MFR_AREA_T area " +
+		                		"inner join MFR_OPEN_FORUM_T openforum on openforum.surrogateKey=area.ID inner " +
+		                		"join MFR_TOPIC_T topic on topic.of_surrogateKey=openforum.ID " +
+		                		"inner join MFR_MEMBERSHIP_ITEM_T membership on topic.ID=membership.t_surrogateKey, " +
+		                		"MFR_PERMISSION_LEVEL_T permission " +
+		                		"where area.CONTEXT_ID = :contextId " +
+		                		"and topic.MODERATED = true " +
+		                		"and (membership.NAME in ( :membershipList ) " +
+		                		"and permission.MODERATE_POSTINGS = true " +
+		                		"and permission.TYPE_UUID <> :customTypeUuid " +
+		                		"and permission.NAME=membership.PERMISSION_LEVEL_NAME)")
+		                		.addScalar("NBR", Hibernate.INTEGER);
+	            	} else {
+	            		q = session.getNamedQuery(QUERY_GET_NUM_MOD_TOPICS_WITH_MOD_PERM_BY_PERM_LEVEL_NAME);
+	            	}
 	                q.setParameterList("membershipList", membershipList);
 	                q.setParameter("contextId", getContextId(), Hibernate.STRING);
 	                q.setParameter("customTypeUuid", typeManager.getCustomLevelType(), Hibernate.STRING);

diff --git a/...pl/src/java/org/sakaiproject/component/app/messageforums/ui/UIPermissionsManagerImpl.java b/...pl/src/java/org/sakaiproject/component/app/messageforums/ui/UIPermissionsManagerImpl.java
@@ -954,7 +954,9 @@ public List getCurrentUserMemberships(String siteId)
 	  List userMemberships = new ArrayList();
 	  // first, add the user's role
 	  final String currRole = getCurrentUserRole(siteId);
-	  userMemberships.add(currRole);
+	  if (currRole != null && !currRole.isEmpty()) {
+		  userMemberships.add(currRole);
+	  }
 	  // now, add any groups the user is a member of
 	  try {
 		  Site site = SiteService.getSite(toolManager.getCurrentPlacement().getContext());

diff --git a/...ums-hbm/src/java/org/sakaiproject/component/app/messageforums/dao/hibernate/Topic.hbm.xml b/...ums-hbm/src/java/org/sakaiproject/component/app/messageforums/dao/hibernate/Topic.hbm.xml
@@ -309,6 +309,7 @@
   </query>
 
   <!-- second check by permissionLevelName if permissionLevel id is null -->
+  <!-- *** If you update this query you need to update the straight join in MessageForumsForumManagerImpl.java *** -->
   <query name="findNumModeratedTopicsForSiteByUserByMembershipWithPermissionLevelName">
     <![CDATA[select count(*) from org.sakaiproject.component.app.messageforums.dao.hibernate.TopicImpl as topic,
     			org.sakaiproject.component.app.messageforums.dao.hibernate.PermissionLevelImpl as pl