Ensure all shards return compareable scores for rescore tests

Author: s1monw

src/test/java/org/elasticsearch/test/integration/search/rescore/QueryRescorerTests.java

@@ -201,13 +201,16 @@ public void testEquivalence() throws Exception {
  for (int i = 0; i < numDocs; i++) {
  client().prepareIndex("test", "type1", String.valueOf(i)).setSource("field1", English.intToEnglish(i)).execute().actionGet();
  }
-
- client().admin().indices().prepareRefresh("test").execute().actionGet();
+ 
+ flush();
+ optimize(); // make sure we don't have a background merge running
+ refresh();
  for (int i = 0; i < numDocs; i++) {
  String intToEnglish = English.intToEnglish(i);
  String query = intToEnglish.split(" ")[0];
  SearchResponse rescored = client()
  .prepareSearch()
+ .setPreference("test") // ensure we hit the same shards for tie-breaking
  .setQuery(QueryBuilders.matchQuery("field1", query).operator(MatchQueryBuilder.Operator.OR))
  .setFrom(0)
  .setSize(10)
@@ -222,13 +225,15 @@ public void testEquivalence() throws Exception {
 
 
  SearchResponse plain = client().prepareSearch()
+ .setPreference("test") // ensure we hit the same shards for tie-breaking
  .setQuery(QueryBuilders.matchQuery("field1", query).operator(MatchQueryBuilder.Operator.OR)).setFrom(0).setSize(10)
  .execute().actionGet();
  // check equivalence
  assertEquivalent(plain, rescored); 
 
  rescored = client()
  .prepareSearch()
+ .setPreference("test") // ensure we hit the same shards for tie-breaking
  .setQuery(QueryBuilders.matchQuery("field1", query).operator(MatchQueryBuilder.Operator.OR))
  .setFrom(0)
  .setSize(10)
@@ -245,6 +250,7 @@ public void testEquivalence() throws Exception {
 
  rescored = client()
  .prepareSearch()
+ .setPreference("test") // ensure we hit the same shards for tie-breaking
  .setQuery(QueryBuilders.matchQuery("field1", query).operator(MatchQueryBuilder.Operator.OR))
  .setFrom(0)
  .setSize(10)