KAFKA-3406; Update CommonClientConfigs.RETRY_BACKOFF_MS_DOC doc string

Author: Manikumar reddy O <manikumar.reddy@gmail.com>

Reviewers: Sriharsha Chintalapani <schintalapani@hortonworks.com>, Ismael Juma <ismael@juma.me.uk>

Closes #1230 from omkreddy/KAFKA-3406

clients/src/main/java/org/apache/kafka/clients/CommonClientConfigs.java

@@ -50,7 +50,7 @@ public class CommonClientConfigs {
     public static final String RECONNECT_BACKOFF_MS_DOC = "The amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all requests sent by the consumer to the broker.";
 
     public static final String RETRY_BACKOFF_MS_CONFIG = "retry.backoff.ms";
-    public static final String RETRY_BACKOFF_MS_DOC = "The amount of time to wait before attempting to retry a failed fetch request to a given topic partition. This avoids repeated fetching-and-failing in a tight loop.";
+    public static final String RETRY_BACKOFF_MS_DOC = "The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios.";
 
     public static final String METRICS_SAMPLE_WINDOW_MS_CONFIG = "metrics.sample.window.ms";
     public static final String METRICS_SAMPLE_WINDOW_MS_DOC = "The window of time a metrics sample is computed over.";