trivial change to add byte serializer to ProducerPerformance; patched by Jun Rao

clients/src/main/java/org/apache/kafka/clients/tools/ProducerPerformance.java

@@ -15,10 +15,7 @@ package org.apache.kafka.clients.tools;
 import java.util.Arrays;
 import java.util.Properties;
 
-import org.apache.kafka.clients.producer.Callback;
-import org.apache.kafka.clients.producer.KafkaProducer;
-import org.apache.kafka.clients.producer.ProducerRecord;
-import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.clients.producer.*;
 
 public class ProducerPerformance {
 
@@ -46,6 +43,8 @@ public class ProducerPerformance {
                 throw new IllegalArgumentException("Invalid property: " + args[i]);
             props.put(pieces[0], pieces[1]);
         }
+        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer");
+        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer");
         KafkaProducer<byte[], byte[]> producer = new KafkaProducer<byte[],byte[]>(props);
 
         /* setup perf test */