logger.debug("Sending fetch chunk request {} to {}", chunkIndex, serverAddr);
final StreamChunkId streamChunkId = new StreamChunkId(streamId, chunkIndex);
handler.addFetchRequest(streamChunkId, callback);
channel.writeAndFlush(new ChunkFetchRequest(streamChunkId)).addListener(
new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
long timeTaken = System.currentTimeMillis() - startTime;