fix master speed issue with immutable copy of in druid server, better exception handling in moving and dropping segments

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)

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;
@@ -247,49 +248,44 @@ public class DruidMaster
 
   public void moveSegment(String from, String to, String segmentName, final LoadPeonCallback callback)
   {
+    try {
       final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
       if (fromServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", from));
+        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));
+        throw new IAE("Unable to find server [%s]", to);
       }
 
       if (to.equalsIgnoreCase(from)) {
-      throw new IllegalArgumentException(
+        throw new IAE("Redundant command to move segment [%s] from [%s] to [%s]", segmentName, from, to);
-          String.format("Redundant command to move segment [%s] from [%s] to [%s]", segmentName, from, to)
-      );
       }
 
       final DataSegment segment = fromServer.getSegment(segmentName);
       if (segment == null) {
-      throw new IllegalArgumentException(
+        throw new IAE("Unable to find segment [%s] on server [%s]", segmentName, from);
-          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));
+        throw new IAE("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));
+        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 IllegalArgumentException(
+        throw new IAE(
-          String.format(
             "Not enough capacity on server [%s] for segment [%s]. Required: %,d, available: %,d.",
             to,
             segment,
             segment.getSize(),
             toHolder.getAvailableSize()
-          )
         );
       }
 
@@ -321,72 +317,39 @@ public class DruidMaster
           }
       );
     }
-
+    catch (Exception e) {
-  public void cloneSegment(String from, String to, String segmentName, LoadPeonCallback callback)
+      log.makeAlert(e, "Exception moving segment %s", segmentName).emit();
-  {
+      callback.execute();
-    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);
     }
   }
 
   public void dropSegment(String from, String segmentName, final LoadPeonCallback callback)
   {
+    try {
       final DruidServer fromServer = serverInventoryView.getInventoryValue(from);
       if (fromServer == null) {
-      throw new IllegalArgumentException(String.format("Unable to find server [%s]", from));
+        throw new IAE("Unable to find server [%s]", from);
       }
 
       final DataSegment segment = fromServer.getSegment(segmentName);
       if (segment == null) {
-      throw new IllegalArgumentException(
+        throw new IAE("Unable to find segment [%s] on server [%s]", segmentName, from);
-          String.format("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));
+        throw new IAE("LoadQueuePeon hasn't been created yet for path [%s]", from);
       }
 
       if (!dropPeon.getSegmentsToDrop().contains(segment)) {
         dropPeon.dropSegment(segment, callback);
       }
     }
+    catch (Exception e) {
+      log.makeAlert(e, "Exception dropping segment %s", segmentName).emit();
+      callback.execute();
+    }
+  }
 
   public Set<DataSegment> getAvailableDataSegments()
   {