diff --git a/client/src/main/java/com/metamx/druid/client/DruidServer.java b/client/src/main/java/com/metamx/druid/client/DruidServer.java
index ebd078e9383..e86efdad816 100644
--- a/client/src/main/java/com/metamx/druid/client/DruidServer.java
+++ b/client/src/main/java/com/metamx/druid/client/DruidServer.java
@@ -25,6 +25,7 @@ import com.google.common.collect.ImmutableMap;
 import com.metamx.common.logger.Logger;
 import com.metamx.druid.coordination.DruidServerMetadata;
 
+import java.util.Collections;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
@@ -116,7 +117,8 @@ public class DruidServer implements Comparable
   @JsonProperty
   public Map<String, DataSegment> getSegments()
   {
-    return ImmutableMap.copyOf(segments);
+    // Copying the map slows things down a lot here, don't use Immutable Map here
+    return Collections.unmodifiableMap(segments);
   }
 
   public DataSegment getSegment(String segmentName)
diff --git a/server/src/main/java/com/metamx/druid/master/DruidMaster.java b/server/src/main/java/com/metamx/druid/master/DruidMaster.java
index c7c39d3fdd3..e0f7b5841ae 100644
--- a/server/src/main/java/com/metamx/druid/master/DruidMaster.java
+++ b/server/src/main/java/com/metamx/druid/master/DruidMaster.java
@@ -28,6 +28,7 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.google.common.io.Closeables;
+import com.metamx.common.IAE;
 import com.metamx.common.Pair;
 import com.metamx.common.concurrent.ScheduledExecutorFactory;
 import com.metamx.common.concurrent.ScheduledExecutors;
@@ -247,144 +248,106 @@ public class DruidMaster
 
   public void moveSegment(String from, String to, String segmentName, final LoadPeonCallback callback)
   {
-    final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
-    if (fromServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", from));
-    }
+    try {
+      final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
+      if (fromServer == null) {
+        throw new IAE("Unable to find server [%s]", from);
+      }
 
-    final DruidServer toServer = serverInventoryView.getInventoryValue(to);
-    if (toServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", to));
-    }
+      final DruidServer toServer = serverInventoryView.getInventoryValue(to);
+      if (toServer == null) {
+        throw new IAE("Unable to find server [%s]", to);
+      }
 
-    if (to.equalsIgnoreCase(from)) {
-      throw new IllegalArgumentException(
-          String.format("Redundant command to move segment [%s] from [%s] to [%s]", segmentName, from, to)
+      if (to.equalsIgnoreCase(from)) {
+        throw new IAE("Redundant command to move segment [%s] from [%s] to [%s]", segmentName, from, to);
+      }
+
+      final DataSegment segment = fromServer.getSegment(segmentName);
+      if (segment == null) {
+        throw new IAE("Unable to find segment [%s] on server [%s]", segmentName, from);
+      }
+
+      final LoadQueuePeon loadPeon = loadManagementPeons.get(to);
+      if (loadPeon == null) {
+        throw new IAE("LoadQueuePeon hasn't been created yet for path [%s]", to);
+      }
+
+      final LoadQueuePeon dropPeon = loadManagementPeons.get(from);
+      if (dropPeon == null) {
+        throw new IAE("LoadQueuePeon hasn't been created yet for path [%s]", from);
+      }
+
+      final ServerHolder toHolder = new ServerHolder(toServer, loadPeon);
+      if (toHolder.getAvailableSize() < segment.getSize()) {
+        throw new IAE(
+            "Not enough capacity on server [%s] for segment [%s]. Required: %,d, available: %,d.",
+            to,
+            segment,
+            segment.getSize(),
+            toHolder.getAvailableSize()
+        );
+      }
+
+      final String toLoadQueueSegPath = ZKPaths.makePath(ZKPaths.makePath(zkPaths.getLoadQueuePath(), to), segmentName);
+      final String toServedSegPath = ZKPaths.makePath(
+          ZKPaths.makePath(zkPaths.getServedSegmentsPath(), to), segmentName
       );
-    }
 
-    final DataSegment segment = fromServer.getSegment(segmentName);
-    if (segment == null) {
-      throw new IllegalArgumentException(
-          String.format("Unable to find segment [%s] on server [%s]", segmentName, from)
-      );
-    }
-
-    final LoadQueuePeon loadPeon = loadManagementPeons.get(to);
-    if (loadPeon == null) {
-      throw new IllegalArgumentException(String.format("LoadQueuePeon hasn't been created yet for path [%s]", to));
-    }
-
-    final LoadQueuePeon dropPeon = loadManagementPeons.get(from);
-    if (dropPeon == null) {
-      throw new IllegalArgumentException(String.format("LoadQueuePeon hasn't been created yet for path [%s]", from));
-    }
-
-    final ServerHolder toHolder = new ServerHolder(toServer, loadPeon);
-    if (toHolder.getAvailableSize() < segment.getSize()) {
-      throw new IllegalArgumentException(
-          String.format(
-              "Not enough capacity on server [%s] for segment [%s]. Required: %,d, available: %,d.",
-              to,
-              segment,
-              segment.getSize(),
-              toHolder.getAvailableSize()
-          )
-      );
-    }
-
-    final String toLoadQueueSegPath = ZKPaths.makePath(ZKPaths.makePath(zkPaths.getLoadQueuePath(), to), segmentName);
-    final String toServedSegPath = ZKPaths.makePath(
-        ZKPaths.makePath(zkPaths.getServedSegmentsPath(), to), segmentName
-    );
-
-    loadPeon.loadSegment(
-        segment,
-        new LoadPeonCallback()
-        {
-          @Override
-          protected void execute()
+      loadPeon.loadSegment(
+          segment,
+          new LoadPeonCallback()
           {
-            try {
-              if (curator.checkExists().forPath(toServedSegPath) != null &&
-                  curator.checkExists().forPath(toLoadQueueSegPath) == null &&
-                  !dropPeon.getSegmentsToDrop().contains(segment)) {
-                dropPeon.dropSegment(segment, callback);
-              } else if (callback != null) {
-                callback.execute();
+            @Override
+            protected void execute()
+            {
+              try {
+                if (curator.checkExists().forPath(toServedSegPath) != null &&
+                    curator.checkExists().forPath(toLoadQueueSegPath) == null &&
+                    !dropPeon.getSegmentsToDrop().contains(segment)) {
+                  dropPeon.dropSegment(segment, callback);
+                } else if (callback != null) {
+                  callback.execute();
+                }
+              }
+              catch (Exception e) {
+                throw Throwables.propagate(e);
               }
             }
-            catch (Exception e) {
-              throw Throwables.propagate(e);
-            }
           }
-        }
-    );
-  }
-
-  public void cloneSegment(String from, String to, String segmentName, LoadPeonCallback callback)
-  {
-    final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
-    if (fromServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", from));
-    }
-
-    final DruidServer toServer = serverInventoryView.getInventoryValue(to);
-    if (toServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", to));
-    }
-
-    final DataSegment segment = fromServer.getSegment(segmentName);
-    if (segment == null) {
-      throw new IllegalArgumentException(
-          String.format("Unable to find segment [%s] on server [%s]", segmentName, from)
       );
     }
-
-    final LoadQueuePeon loadPeon = loadManagementPeons.get(to);
-    if (loadPeon == null) {
-      throw new IllegalArgumentException(String.format("LoadQueuePeon hasn't been created yet for path [%s]", to));
-    }
-
-    final ServerHolder toHolder = new ServerHolder(toServer, loadPeon);
-    if (toHolder.getAvailableSize() < segment.getSize()) {
-      throw new IllegalArgumentException(
-          String.format(
-              "Not enough capacity on server [%s] for segment [%s]. Required: %,d, available: %,d.",
-              to,
-              segment,
-              segment.getSize(),
-              toHolder.getAvailableSize()
-          )
-      );
-    }
-
-    if (!loadPeon.getSegmentsToLoad().contains(segment)) {
-      loadPeon.loadSegment(segment, callback);
+    catch (Exception e) {
+      log.makeAlert(e, "Exception moving segment %s", segmentName).emit();
+      callback.execute();
     }
   }
 
   public void dropSegment(String from, String segmentName, final LoadPeonCallback callback)
   {
-    final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
-    if (fromServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", from));
-    }
+    try {
+      final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
+      if (fromServer == null) {
+        throw new IAE("Unable to find server [%s]", from);
+      }
 
-    final DataSegment segment = fromServer.getSegment(segmentName);
-    if (segment == null) {
-      throw new IllegalArgumentException(
-          String.format("Unable to find segment [%s] on server [%s]", segmentName, from)
-      );
-    }
+      final DataSegment segment = fromServer.getSegment(segmentName);
+      if (segment == null) {
+        throw new IAE("Unable to find segment [%s] on server [%s]", segmentName, from);
+      }
 
-    final LoadQueuePeon dropPeon = loadManagementPeons.get(from);
-    if (dropPeon == null) {
-      throw new IllegalArgumentException(String.format("LoadQueuePeon hasn't been created yet for path [%s]", from));
-    }
+      final LoadQueuePeon dropPeon = loadManagementPeons.get(from);
+      if (dropPeon == null) {
+        throw new IAE("LoadQueuePeon hasn't been created yet for path [%s]", from);
+      }
 
-    if (!dropPeon.getSegmentsToDrop().contains(segment)) {
-      dropPeon.dropSegment(segment, callback);
+      if (!dropPeon.getSegmentsToDrop().contains(segment)) {
+        dropPeon.dropSegment(segment, callback);
+      }
+    }
+    catch (Exception e) {
+      log.makeAlert(e, "Exception dropping segment %s", segmentName).emit();
+      callback.execute();
     }
   }
 
@@ -543,7 +506,7 @@ public class DruidMaster
       }
       catch (Exception e) {
         log.makeAlert(e, "Unable to become master")
-            .emit();
+           .emit();
         final LeaderLatch oldLatch = createNewLeaderLatch();
         Closeables.closeQuietly(oldLatch);
         try {