diff --git a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/Generator.java b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/Generator.java
index 3925e02..4279304 100644
--- a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/Generator.java
+++ b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/Generator.java
@@ -102,10 +102,12 @@
                 } else if (line.contains("@METHODS@")) {
                     for (int i = 0; i < resource.size(); ++i) {
                         final Field field = resource.fields.get(i);
-                        field.appendMemoryManagerGetMethod(sb, indent, 1);
-                        sb.append('\n');
-                        field.appendMemoryManagerSetMethod(sb, indent, 1);
-                        sb.append('\n');
+                        if (field.accessible) {
+                            field.appendMemoryManagerGetMethod(sb, indent, 1);
+                            sb.append('\n');
+                            field.appendMemoryManagerSetMethod(sb, indent, 1);
+                            sb.append('\n');
+                        }
                     }
                 } else if (line.contains("@INIT_SLOT@")) {
                     for (int i = 0; i < resource.size(); ++i) {                        
@@ -152,10 +154,12 @@
                 if (line.contains("@METHODS@")) {
                     for (int i = 0; i < resource.size(); ++i) {
                         final Field field = resource.fields.get(i);
-                        field.appendArenaManagerGetMethod(sb, indent, 1);
-                        sb.append('\n');
-                        field.appendArenaManagerSetMethod(sb, indent, 1);
-                        sb.append('\n');
+                        if (field.accessible) {
+                            field.appendArenaManagerGetMethod(sb, indent, 1);
+                            sb.append('\n');
+                            field.appendArenaManagerSetMethod(sb, indent, 1);
+                            sb.append('\n');
+                        }
                     }
                 } else {
                   sb.append(line).append('\n');
diff --git a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordManagerGeneratorMojo.java b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordManagerGeneratorMojo.java
index 577d871..8b6b581 100644
--- a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordManagerGeneratorMojo.java
+++ b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordManagerGeneratorMojo.java
@@ -85,9 +85,9 @@
         resource.addField("max mode", RecordType.Type.INT, "LockMode.NL");
         resource.addField("dataset id", RecordType.Type.INT, null);
         resource.addField("pk hash val", RecordType.Type.INT, null);
-        resource.addField("alloc id", RecordType.Type.SHORT, null, true);
+        resource.addField("alloc id", RecordType.Type.SHORT, null);
 
-        typeMap.put(resource.name, resource);
+        resource.addToMap(typeMap);
 
         RecordType request = new RecordType("Request");
         request.addField("resource id", RecordType.Type.GLOBAL, null);
@@ -96,18 +96,18 @@
         request.addField("next job request", RecordType.Type.GLOBAL, null);
         request.addField("next request", RecordType.Type.GLOBAL, null);
         request.addField("lock mode", RecordType.Type.INT, null);
-        request.addField("alloc id", RecordType.Type.SHORT, null, true);
+        request.addField("alloc id", RecordType.Type.SHORT, null);
 
-        typeMap.put(request.name, request);
+        request.addToMap(typeMap);
 
         RecordType job = new RecordType("Job");
         job.addField("last holder", RecordType.Type.GLOBAL, "-1");
         job.addField("last waiter", RecordType.Type.GLOBAL, "-1");
         job.addField("last upgrader", RecordType.Type.GLOBAL, "-1");
         job.addField("job id", RecordType.Type.INT, null);
-        job.addField("alloc id", RecordType.Type.SHORT, null, true);
+        job.addField("alloc id", RecordType.Type.SHORT, null);
 
-        typeMap.put(job.name, job);
+        job.addToMap(typeMap);
     }
 
     public void execute() throws MojoExecutionException, MojoFailureException {
diff --git a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordType.java b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordType.java
index 6a0d540..741311b 100644
--- a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordType.java
+++ b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/java/edu/uci/ics/asterix/recordmanagergenerator/RecordType.java
@@ -15,7 +15,11 @@
 
 package edu.uci.ics.asterix.recordmanagergenerator;
 
+import java.security.AlgorithmConstraints;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Map;
 
 public class RecordType {
     
@@ -27,19 +31,19 @@
     }
     
     static class Field {
-        
+                
         String name;
         Type type;
         String initial;
         int offset;
-        boolean debugField;
+        boolean accessible = true;
 
-        Field(String name, Type type, String initial, int offset, boolean debugField) {
+        Field(String name, Type type, String initial, int offset, boolean accessible) {
             this.name = name;
             this.type = type;
             this.initial = initial;
             this.offset = offset;
-            this.debugField = debugField;
+            this.accessible = accessible;
         }
         
         String methodName(String prefix) {
@@ -105,7 +109,7 @@
               .append(' ')
               .append(methodName("get"))
               .append("(long slotNum) {\n");
-            if (! debugField) {
+            if (initial != null) {
               sb = indent(sb, indent, level + 1);
               sb.append("if (TRACK_ALLOC) checkSlot(slotNum);\n");
             }
@@ -129,7 +133,7 @@
               .append("(long slotNum, ")
               .append(javaType(type))
               .append(" value) {\n");
-            if (! debugField) {
+            if (initial != null) {
               sb = indent(sb, indent, level + 1);
               sb.append("if (TRACK_ALLOC) checkSlot(slotNum);\n");
             }
@@ -163,7 +167,7 @@
         }
         
         StringBuilder appendChecks(StringBuilder sb, String indent, int level) {
-            if (debugField) {
+            if (initial == null) {
                 return sb;
             }
             sb = indent(sb, indent, level);
@@ -204,6 +208,7 @@
     String name;
     ArrayList<Field> fields;
     int totalSize;
+    boolean modifiable = true;
     
     static StringBuilder indent(StringBuilder sb, String indent, int level) {
         for (int i = 0; i < level; ++i) {
@@ -212,21 +217,51 @@
         return sb;
     }
     
-    RecordType(String name) {
+    public RecordType(String name) {
         this.name = name;
         fields = new ArrayList<Field>();
-        totalSize = 0;
+        addField("next free slot", Type.INT, "-1", false);
     }
     
-    void addField(String name, Type type, String initial) {
-        addField(name, type, initial, false);
+    public void addToMap(Map<String, RecordType> map) {
+        modifiable = false;
+        calcOffsetsAndSize();
+        map.put(name, this);
+    }
+
+    public void addField(String name, Type type, String initial) {
+        addField(name, type, initial, true);
+    }    
+    
+    private void addField(String name, Type type, String initial, boolean accessible) {
+        if (! modifiable) {
+            throw new IllegalStateException("cannot modify type anmore");
+        }
+        fields.add(new Field(name, type, initial, -1, accessible));
     }
      
-    void addField(String name, Type type, String initial, boolean debugField) {
-        fields.add(new Field(name, type, initial, totalSize, debugField));
-        totalSize += size(type);
+    private void calcOffsetsAndSize() {
+        Collections.sort(fields, new Comparator<Field>() {
+            public int compare(Field left, Field right) {
+                return size(right.type) - size(left.type);
+            }
+        });
+        // sort fields by size and align the items
+        totalSize = 0;
+        int alignment = 0;
+        for (int i = 0; i < fields.size(); ++i) {            
+            final Field field = fields.get(i);
+            assert field.offset == -1;
+            field.offset = totalSize;
+            final int size = size(field.type);
+            totalSize += size;
+            if (size > alignment) alignment = size;
+        }
+        if (totalSize % alignment != 0) {
+            totalSize = ((totalSize / alignment) + 1) * alignment; 
+        }
     }
-     
+    
     int size() {
         return fields.size();
     }
@@ -310,7 +345,8 @@
             sb.append("public static int ")
               .append(field.offsetName())
               .append(" = ")
-              .append(field.offset).append(";\n");
+              .append(field.offset).append("; // size: ")
+              .append(size(field.type)).append("\n");
         }
         return sb;
     }
@@ -342,6 +378,8 @@
             sb.append("sb = ")
               .append(appender(field.type))
               .append("(sb, value);\n");
+            sb = indent(sb, indent, level + 1);
+            sb.append("sb.append(\" | \");\n");
             sb = indent(sb, indent, level);
             sb.append("}\n");
             sb = indent(sb, indent, level);
diff --git a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/ArenaManager.java b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/ArenaManager.java
index 5d0a2d8..58f8972 100644
--- a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/ArenaManager.java
+++ b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/ArenaManager.java
@@ -25,11 +25,13 @@
     public static final boolean TRACK_ALLOC = @DEBUG@;
 
     private final int noArenas;
+    private final long txnShrinkTimer;
     private ArrayList<@E@RecordManager> arenas;
     private volatile int nextArena; 
     private ThreadLocal<LocalManager> local;    
     
-    public @E@ArenaManager() {
+    public @E@ArenaManager(long txnShrinkTimer) {
+        this.txnShrinkTimer = txnShrinkTimer;
         noArenas = Runtime.getRuntime().availableProcessors() * 2;
         arenas = new ArrayList<@E@RecordManager>(noArenas);
         nextArena = 0;
@@ -68,7 +70,7 @@
     
     public synchronized LocalManager getNext() {
         if (nextArena >= arenas.size()) { 
-            arenas.add(new @E@RecordManager());
+            arenas.add(new @E@RecordManager(txnShrinkTimer));
         }
         @E@RecordManager mgr = arenas.get(nextArena);
         LocalManager res = new LocalManager();
@@ -125,4 +127,13 @@
     public String toString() {
         return append(new StringBuilder()).toString();
     }
+
+    public Stats addTo(Stats s) {
+        final int size = arenas.size();
+        s.arenas += size;
+        for (int i = 0; i < size; ++i) {
+            arenas.get(i).addTo(s);
+        }
+        return s;
+    }
 }
diff --git a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/RecordManager.java b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/RecordManager.java
index e5ce5c1..01049d3 100644
--- a/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/RecordManager.java
+++ b/asterix-maven-plugins/record-manager-generator-maven-plugin/src/main/resources/RecordManager.java
@@ -23,23 +23,23 @@
 
 public class @E@RecordManager {
 
-    public static final int SHRINK_TIMER_THRESHOLD = 120000; //2min
     public static final boolean TRACK_ALLOC = @DEBUG@;
     
     static final int NO_SLOTS = 10;
-    static final int NEXT_FREE_SLOT_OFFSET = 0;
 
     @CONSTS@
 
+    private final long txnShrinkTimer;
+    private long shrinkTimer;
     private ArrayList<Buffer> buffers;
     private int current;
     private int occupiedSlots;
-    private long shrinkTimer;
     private boolean isShrinkTimerOn;
 
     int allocCounter;
     
-    public @E@RecordManager() {
+    public @E@RecordManager(long txnShrinkTimer) {
+        this.txnShrinkTimer = txnShrinkTimer;
         buffers = new ArrayList<Buffer>();
         buffers.add(new Buffer());
         current = 0;
@@ -106,7 +106,7 @@
 
         if (size > 1 && size * NO_SLOTS / usedSlots >= 3) {
             if (isShrinkTimerOn) {
-                if (System.currentTimeMillis() - shrinkTimer >= SHRINK_TIMER_THRESHOLD) {
+                if (System.currentTimeMillis() - shrinkTimer >= txnShrinkTimer) {
                     isShrinkTimerOn = false;
                     return true;
                 }
@@ -190,6 +190,17 @@
         return append(new StringBuilder()).toString();
     }
 
+    public Stats addTo(Stats s) {
+        final int size = buffers.size();
+        s.buffers += size;
+        s.slots += size * NO_SLOTS;
+        s.size += size * NO_SLOTS * ITEM_SIZE;
+        for (int i = 0; i < size; ++i) {
+            buffers.get(i).addTo(s);
+        }
+        return s;
+    }
+    
     static class Buffer {
         private ByteBuffer bb;
         private int freeSlotNum;
@@ -254,11 +265,11 @@
         }
 
         public int getNextFreeSlot(int slotNum) {
-            return bb.getInt(slotNum * ITEM_SIZE + NEXT_FREE_SLOT_OFFSET);
+            return bb.getInt(slotNum * ITEM_SIZE + NEXT_FREE_SLOT_OFF);
         }    
             
         public void setNextFreeSlot(int slotNum, int nextFreeSlot) {
-            bb.putInt(slotNum * ITEM_SIZE + NEXT_FREE_SLOT_OFFSET, nextFreeSlot);
+            bb.putInt(slotNum * ITEM_SIZE + NEXT_FREE_SLOT_OFF, nextFreeSlot);
         }
 
         StringBuilder append(StringBuilder sb) {
@@ -275,6 +286,12 @@
             return append(new StringBuilder()).toString();
         }
         
+        public void addTo(Stats s) {
+            if (isInitialized()) {
+                s.items += occupiedSlots;
+            }
+        }
+        
         private void checkSlot(int slotNum) {
             if (! TRACK_ALLOC) {
                 return;
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/ConcurrentLockManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/ConcurrentLockManager.java
index 18997e5..124b406 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/ConcurrentLockManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/ConcurrentLockManager.java
@@ -28,7 +28,6 @@
 import edu.uci.ics.asterix.common.transactions.ILockManager;
 import edu.uci.ics.asterix.common.transactions.ITransactionContext;
 import edu.uci.ics.asterix.common.transactions.ITransactionManager;
-import edu.uci.ics.asterix.common.transactions.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.api.lifecycle.ILifeCycleComponent;
@@ -77,9 +76,9 @@
         final int lockManagerShrinkTimer = txnSubsystem.getTransactionProperties()
                 .getLockManagerShrinkTimer();
 
-        resArenaMgr = new ResourceArenaManager();
-        reqArenaMgr = new RequestArenaManager();
-        jobArenaMgr = new JobArenaManager();
+        resArenaMgr = new ResourceArenaManager(lockManagerShrinkTimer);
+        reqArenaMgr = new RequestArenaManager(lockManagerShrinkTimer);
+        jobArenaMgr = new JobArenaManager(lockManagerShrinkTimer);
         jobIdSlotMap = new ConcurrentHashMap<>();
     }
 
@@ -107,6 +106,8 @@
         group.getLatch();
 
         try {
+            validateJob(txnContext);
+            
             // 1) Find the resource in the hash table
             long resSlot = getResourceSlot(group, dsId, entityHashValue);
             // 2) create a request entry
@@ -211,6 +212,8 @@
         group.getLatch();
 
         try {
+            validateJob(txnContext);
+
             // 1) Find the resource in the hash table
             long resSlot = getResourceSlot(group, dsId, entityHashValue);
             // 2) create a request entry
@@ -338,6 +341,10 @@
             holder = jobArenaMgr.getLastHolder(jobSlot);
         }
         jobArenaMgr.deallocate(jobSlot);
+        
+        //System.out.println("jobArenaMgr " + jobArenaMgr.addTo(new Stats()).toString());
+        //System.out.println("resArenaMgr " + resArenaMgr.addTo(new Stats()).toString());
+        //System.out.println("reqArenaMgr " + reqArenaMgr.addTo(new Stats()).toString());
     }
         
     private long getJobSlot(int jobId) {
@@ -441,8 +448,8 @@
         resArenaMgr.setLastHolder(resource, request);
         
         synchronized (jobArenaMgr) {
-            lastHolder = jobArenaMgr.getLastHolder(job);
-            insertIntoJobQueue(request, lastHolder);
+            long lastJobHolder = jobArenaMgr.getLastHolder(job);
+            insertIntoJobQueue(request, lastJobHolder);
             jobArenaMgr.setLastHolder(job, request);
         }
     }
@@ -796,7 +803,7 @@
     @Override
     public String prettyPrint() throws ACIDException {
         StringBuilder s = new StringBuilder("\n########### LockManager Status #############\n");
-        return s + "\n";
+        return append(s).toString() + "\n";
     }
 
     @Override
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/Stats.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/Stats.java
new file mode 100644
index 0000000..ff2c92a
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/Stats.java
@@ -0,0 +1,19 @@
+package edu.uci.ics.asterix.transaction.management.service.locking;
+
+public class Stats {
+    int arenas  = 0;
+    int buffers = 0;
+    int slots   = 0;
+    int items   = 0;
+    int size    = 0;
+    
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("{ arenas : ").append(arenas);
+        sb.append(", buffers : ").append(buffers);
+        sb.append(", slots : ").append(slots);
+        sb.append(", items : ").append(items);
+        sb.append(", size : ").append(size).append(" }");
+        return sb.toString();
+    }
+}