diff --git a/modules/elasticsearch/src/main/java/org/elasticsearch/action/index/IndexRequest.java b/modules/elasticsearch/src/main/java/org/elasticsearch/action/index/IndexRequest.java
index 4ae71bee5c6..19c58c31398 100644
--- a/modules/elasticsearch/src/main/java/org/elasticsearch/action/index/IndexRequest.java
+++ b/modules/elasticsearch/src/main/java/org/elasticsearch/action/index/IndexRequest.java
@@ -19,6 +19,7 @@
 
 package org.elasticsearch.action.index;
 
+import org.apache.lucene.util.UnicodeUtil;
 import org.elasticsearch.ElasticSearchGenerationException;
 import org.elasticsearch.ElasticSearchIllegalArgumentException;
 import org.elasticsearch.action.ActionRequestValidationException;
@@ -34,6 +35,7 @@ import org.elasticsearch.util.xcontent.builder.BinaryXContentBuilder;
 import org.elasticsearch.util.xcontent.builder.XContentBuilder;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Map;
 
 import static org.elasticsearch.action.Actions.*;
@@ -102,10 +104,13 @@ public class IndexRequest extends ShardReplicationOperationRequest {
 
     private String type;
     private String id;
-    private byte[] source;
-    private OpType opType = OpType.INDEX;
 
-    private transient XContentBuilder sourceBuilder;
+    private byte[] source;
+    private int sourceOffset;
+    private int sourceLength;
+    private boolean sourceUnsafe;
+
+    private OpType opType = OpType.INDEX;
 
     public IndexRequest() {
     }
@@ -138,12 +143,19 @@ public class IndexRequest extends ShardReplicationOperationRequest {
         if (type == null) {
             validationException = addValidationError("type is missing", validationException);
         }
-        if (source == null && sourceBuilder == null) {
+        if (source == null) {
             validationException = addValidationError("source is missing", validationException);
         }
         return validationException;
     }
 
+    /**
+     * Before we fork on a local thread, make sure we copy over the bytes if they are unsafe
+     */
+    @Override protected void beforeLocalFork() {
+        source();
+    }
+
     /**
      * Sets the index the index operation will happen on.
      */
@@ -203,12 +215,9 @@ public class IndexRequest extends ShardReplicationOperationRequest {
      * The source of the JSON document to index.
      */
     byte[] source() {
-        if (source == null && sourceBuilder != null) {
-            try {
-                source = sourceBuilder.copiedBytes();
-            } catch (IOException e) {
-                throw new ElasticSearchGenerationException("Failed to build source", e);
-            }
+        if (sourceUnsafe) {
+            source = Arrays.copyOfRange(source, sourceOffset, sourceLength);
+            sourceUnsafe = false;
         }
         return source;
     }
@@ -223,7 +232,7 @@ public class IndexRequest extends ShardReplicationOperationRequest {
     }
 
     /**
-     * Writes the JSON as the provided content type.
+     * Writes the Map as the provided content type.
      *
      * @param source The map to index
      */
@@ -231,21 +240,24 @@ public class IndexRequest extends ShardReplicationOperationRequest {
         try {
             BinaryXContentBuilder builder = XContentFactory.contentBinaryBuilder(contentType);
             builder.map(source);
-            this.source = builder.copiedBytes();
+            return source(builder);
         } catch (IOException e) {
             throw new ElasticSearchGenerationException("Failed to generate [" + source + "]", e);
         }
-        return this;
     }
 
     /**
-     * Sets the JSON source to index.
+     * Sets the document source to index.
      *
      * <p>Note, its preferable to either set it using {@link #source(org.elasticsearch.util.xcontent.builder.XContentBuilder)}
      * or using the {@link #source(byte[])}.
      */
     @Required public IndexRequest source(String source) {
-        this.source = Unicode.fromStringAsBytes(source);
+        UnicodeUtil.UTF8Result result = Unicode.fromStringAsUtf8(source);
+        this.source = result.result;
+        this.sourceOffset = 0;
+        this.sourceLength = result.length;
+        this.sourceUnsafe = true;
         return this;
     }
 
@@ -253,15 +265,51 @@ public class IndexRequest extends ShardReplicationOperationRequest {
      * Sets the content source to index.
      */
     @Required public IndexRequest source(XContentBuilder sourceBuilder) {
-        this.sourceBuilder = sourceBuilder;
+        try {
+            source = sourceBuilder.unsafeBytes();
+            sourceOffset = 0;
+            sourceLength = sourceBuilder.unsafeBytesLength();
+            sourceUnsafe = true;
+        } catch (IOException e) {
+            throw new ElasticSearchGenerationException("Failed to generate [" + sourceBuilder + "]", e);
+        }
         return this;
     }
 
     /**
-     * Sets the JSON source to index.
+     * Sets the document to index in bytes form.
      */
-    @Required public IndexRequest source(byte[] source) {
+    public IndexRequest source(byte[] source) {
+        return source(source, 0, source.length);
+    }
+
+    /**
+     * Sets the document to index in bytes form (assumed to be safe to be used from different
+     * threads).
+     *
+     * @param source The source to index
+     * @param offset The offset in the byte array
+     * @param length The length of the data
+     * @return
+     */
+    @Required public IndexRequest source(byte[] source, int offset, int length) {
+        return source(source, offset, length, false);
+    }
+
+    /**
+     * Sets the document to index in bytes form.
+     *
+     * @param source The source to index
+     * @param offset The offset in the byte array
+     * @param length The length of the data
+     * @param unsafe Is the byte array safe to be used form a different thread
+     * @return
+     */
+    @Required public IndexRequest source(byte[] source, int offset, int length, boolean unsafe) {
         this.source = source;
+        this.sourceOffset = offset;
+        this.sourceLength = length;
+        this.sourceUnsafe = unsafe;
         return this;
     }
 
@@ -319,8 +367,13 @@ public class IndexRequest extends ShardReplicationOperationRequest {
         if (in.readBoolean()) {
             id = in.readUTF();
         }
-        source = new byte[in.readVInt()];
+
+        sourceUnsafe = false;
+        sourceOffset = 0;
+        sourceLength = in.readVInt();
+        source = new byte[sourceLength];
         in.readFully(source);
+
         opType = OpType.fromId(in.readByte());
     }
 
@@ -333,17 +386,12 @@ public class IndexRequest extends ShardReplicationOperationRequest {
             out.writeBoolean(true);
             out.writeUTF(id);
         }
-        if (source != null) {
-            out.writeVInt(source.length);
-            out.writeBytes(source);
-        } else {
-            out.writeVInt(sourceBuilder.unsafeBytesLength());
-            out.writeBytes(sourceBuilder.unsafeBytes(), 0, sourceBuilder.unsafeBytesLength());
-        }
+        out.writeVInt(sourceLength);
+        out.writeBytes(source, sourceOffset, sourceLength);
         out.writeByte(opType.id());
     }
 
     @Override public String toString() {
-        return "[" + index + "][" + type + "][" + id + "], source[" + Unicode.fromBytes(source) + "]";
+        return "[" + index + "][" + type + "][" + id + "], source[" + Unicode.fromBytes(source, sourceOffset, sourceLength) + "]";
     }
 }
\ No newline at end of file
diff --git a/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/ShardReplicationOperationRequest.java b/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/ShardReplicationOperationRequest.java
index 86fa6102842..355ddb1b908 100644
--- a/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/ShardReplicationOperationRequest.java
+++ b/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/ShardReplicationOperationRequest.java
@@ -107,4 +107,11 @@ public abstract class ShardReplicationOperationRequest implements ActionRequest
         timeout.writeTo(out);
         out.writeUTF(index);
     }
+
+    /**
+     * Called before the request gets forked into a local thread.
+     */
+    protected void beforeLocalFork() {
+
+    }
 }
diff --git a/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/TransportShardReplicationOperationAction.java b/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/TransportShardReplicationOperationAction.java
index 307c55ba8d3..3066b050963 100644
--- a/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/TransportShardReplicationOperationAction.java
+++ b/modules/elasticsearch/src/main/java/org/elasticsearch/action/support/replication/TransportShardReplicationOperationAction.java
@@ -246,6 +246,7 @@ public abstract class TransportShardReplicationOperationAction<Request extends S
                     foundPrimary = true;
                     if (shard.currentNodeId().equals(nodes.localNodeId())) {
                         if (request.operationThreaded()) {
+                            request.beforeLocalFork();
                             threadPool.execute(new Runnable() {
                                 @Override public void run() {
                                     performOnPrimary(shard.id(), fromClusterEvent, true, shard);
@@ -434,6 +435,7 @@ public abstract class TransportShardReplicationOperationAction<Request extends S
                 });
             } else {
                 if (request.operationThreaded()) {
+                    request.beforeLocalFork();
                     threadPool.execute(new Runnable() {
                         @Override public void run() {
                             try {