Bug 1337995 REST fetch of groups doesn't scale

- Don't pull in all resources for every fetched group
- Avoid umbrella transaction

modules/enterprise/server/jar/src/main/java/org/rhq/enterprise/server/rest/AbstractRestBean.java

@@ -45,17 +45,10 @@
 import javax.ws.rs.core.UriBuilder;
 import javax.ws.rs.core.UriInfo;
 
-import freemarker.cache.ClassTemplateLoader;
-import freemarker.cache.MultiTemplateLoader;
-import freemarker.cache.TemplateLoader;
-import freemarker.template.Template;
-import freemarker.template.TemplateException;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.infinispan.Cache;
 import org.infinispan.manager.CacheContainer;
-
 import org.rhq.core.domain.auth.Subject;
 import org.rhq.core.domain.measurement.DataType;
 import org.rhq.core.domain.measurement.MeasurementDefinition;
@@ -74,6 +67,12 @@
 import org.rhq.enterprise.server.rest.domain.PagingCollection;
 import org.rhq.enterprise.server.rest.domain.ResourceWithType;
 
+import freemarker.cache.ClassTemplateLoader;
+import freemarker.cache.MultiTemplateLoader;
+import freemarker.cache.TemplateLoader;
+import freemarker.template.Template;
+import freemarker.template.TemplateException;
+
 /**
  * Abstract base class for EJB classes that implement REST methods.
  * For the cache and its eviction policies see standalone-full.xml (in
@@ -573,8 +572,14 @@ protected GroupRest fillGroup(ResourceGroup group, UriInfo uriInfo) {
         if (group.getGroupDefinition()!=null) {
             gr.setDynaGroupDefinitionId(group.getGroupDefinition().getId());
         }
-        gr.setExplicitCount(group.getExplicitResources().size());
-        gr.setImplicitCount(group.getImplicitResources().size());
+        int expCount = resourceGroupManager.getExplicitGroupMemberCount(group.getId());
+        int impCount = expCount;
+        if (group.isRecursive() && expCount > 0) {
+            impCount = resourceGroupManager.getImplicitGroupMemberCount(group.getId());
+        }
+        gr.setExplicitCount(expCount);
+        gr.setImplicitCount(impCount);
+
         UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
         uriBuilder.path("/group/{id}");
         URI uri = uriBuilder.build(group.getId());

modules/enterprise/server/jar/src/main/java/org/rhq/enterprise/server/rest/GroupHandlerBean.java

@@ -26,6 +26,8 @@
 
 import javax.ejb.EJB;
 import javax.ejb.Stateless;
+import javax.ejb.TransactionAttribute;
+import javax.ejb.TransactionAttributeType;
 import javax.interceptor.Interceptors;
 import javax.ws.rs.Consumes;
 import javax.ws.rs.DELETE;
@@ -44,18 +46,10 @@
 import javax.ws.rs.core.UriBuilder;
 import javax.ws.rs.core.UriInfo;
 
-import com.wordnik.swagger.annotations.Api;
-import com.wordnik.swagger.annotations.ApiError;
-import com.wordnik.swagger.annotations.ApiErrors;
-import com.wordnik.swagger.annotations.ApiOperation;
-import com.wordnik.swagger.annotations.ApiParam;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.jboss.resteasy.annotations.GZIP;
 import org.jboss.resteasy.annotations.cache.Cache;
-
 import org.rhq.core.domain.criteria.ResourceGroupCriteria;
 import org.rhq.core.domain.criteria.ResourceGroupDefinitionCriteria;
 import org.rhq.core.domain.measurement.DataType;
@@ -83,6 +77,12 @@
 import org.rhq.enterprise.server.rest.domain.MetricSchedule;
 import org.rhq.enterprise.server.rest.domain.ResourceWithType;
 
+import com.wordnik.swagger.annotations.Api;
+import com.wordnik.swagger.annotations.ApiError;
+import com.wordnik.swagger.annotations.ApiErrors;
+import com.wordnik.swagger.annotations.ApiOperation;
+import com.wordnik.swagger.annotations.ApiParam;
+
 /**
  * Deal with group related things.
  * @author Heiko W. Rupp
@@ -109,12 +109,14 @@ public class GroupHandlerBean extends AbstractRestBean  {
     @GET
     @Path("/")
     @ApiOperation(value = "List all groups", multiValueResponse = true, responseClass = "GroupRest")
+    @TransactionAttribute(TransactionAttributeType.NOT_SUPPORTED)
     public Response getGroups(@ApiParam("String to search in the group name") @QueryParam("q") String q,
                               @ApiParam("Page size for paging") @QueryParam("ps") @DefaultValue("20") int pageSize,
                               @ApiParam("Page number for paging, 0-based") @QueryParam("page") Integer page,
                               @Context HttpHeaders headers, @Context UriInfo uriInfo) {
 
         ResourceGroupCriteria criteria = new ResourceGroupCriteria();
+        criteria.fetchGroupDefinition(true);
         criteria.addSortId(PageOrdering.ASC);
 
         if (q!=null) {