1. fix asterixdb issue 782
   --- push nested pipeline before a nested group-by operator into the combiner group-by operator in the AbstractIntroduceGroupByCombinerRule
   --- add a processNullTest abstract method in the AbstractIntroduceGroupByCombinerRule
   --  fix the join order in a subplan
2. allow user-configurable buffer cache page size (B-tree page size) in Pregelix

commit 4d9a11d0c05281a41bbabe03066478fe851b3a2b
Author: buyingyi <buyingyi@gmail.com>

Change-Id: Ib7761370df8606c55ac34c126554319586e824f0
Reviewed-on: http://fulliautomatix.ics.uci.edu:8443/64
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <westmann@gmail.com>
diff --git a/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties b/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
index 79f42ed..82a7bfe 100644
--- a/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
+++ b/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
@@ -16,7 +16,7 @@
 CC_CLIENTPORT=3099
 
 #The CC port for Hyracks cluster management
-CC_CLUSTERPORT=1099
+CC_CLUSTERPORT=4099
 
 #The CC port for REST communication
 CC_HTTPPORT=16001
@@ -42,6 +42,9 @@
 #The frame size of the internal dataflow engine
 FRAME_SIZE=65536
 
+#The frame size of the vertex storage, it should be larger than the largest vertex byte size
+VFRAME_SIZE=65536
+
 #The number of jobs whose logs are kept in-memory on the CC
 JOB_HISTORY_SIZE=0