Boost default scroll size to 1000 (#1429)

Author: jbaiera

docs/src/reference/asciidoc/core/configuration.adoc

@@ -510,8 +510,8 @@ available {es} node (based on the declaration of `es.nodes`, followed by the dis
 `es.scroll.keepalive` (default 10m)::
 The maximum duration of result scrolls between query requests.
 
-`es.scroll.size` (default 50)::
-Number of results/items returned by each individual per request.
+`es.scroll.size` (default 1000)::
+Number of results/items/documents returned per scroll request on each executor/worker/task.
 
 added[2.2]
 `es.scroll.limit` (default -1)::

mr/src/main/java/org/elasticsearch/hadoop/cfg/ConfigurationOptions.java

@@ -114,7 +114,7 @@ public interface ConfigurationOptions {
 
     /** Scroll size */
     String ES_SCROLL_SIZE = "es.scroll.size";
-    String ES_SCROLL_SIZE_DEFAULT = "50";
+    String ES_SCROLL_SIZE_DEFAULT = "1000";
 
     /** Scroll limit */
     String ES_SCROLL_LIMIT = "es.scroll.limit";