SOLR-5718: Make LBHttpSolrServer zombie checks non-distrib and non-scoring.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1568394 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -334,6 +334,9 @@ Bug Fixes
 * SOLR-5731: In ConnectionManager, we should catch and only log exceptions
   from BeforeReconnect. (Mark Miller)
 
+* SOLR-5718: Make LBHttpSolrServer zombie checks non-distrib and non-scoring.
+  (Christine Poerschke via Mark Miller)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/handler/component/SearchHandler.java

@@ -268,7 +268,7 @@ public class SearchHandler extends RequestHandlerBase implements SolrCoreAware ,
             for (String shard : sreq.actualShards) {
               ModifiableSolrParams params = new ModifiableSolrParams(sreq.params);
               params.remove(ShardParams.SHARDS);      // not a top-level request
-              params.set("distrib", "false");               // not a top-level request
+              params.set(CommonParams.DISTRIB, "false");               // not a top-level request
               params.remove("indent");
               params.remove(CommonParams.HEADER_ECHO_PARAMS);
               params.set(ShardParams.IS_SHARD, true);  // a sub (shard) request

solr/solrj/src/java/org/apache/solr/client/solrj/SolrQuery.java

@@ -42,6 +42,8 @@ import java.util.regex.Pattern;
  */
 public class SolrQuery extends ModifiableSolrParams 
 {  
+  public static final String DOCID = "_docid_"; // duplicate of org.apache.solr.search.QueryParsing.DOCID which is not accessible from here
+  
   public enum ORDER { desc, asc;
     public ORDER reverse() {
       return (this == asc) ? desc : asc;
@@ -897,6 +899,10 @@ public class SolrQuery extends ModifiableSolrParams
     this.set(CommonParams.DEBUG_QUERY, String.valueOf(showDebugInfo));
   }
 
+  public void setDistrib(boolean val) {
+    this.set(CommonParams.DISTRIB, String.valueOf(val));
+  }
+
 
   public SolrQuery setStart(Integer start) {
     if( start == null ) {

solr/solrj/src/java/org/apache/solr/client/solrj/impl/LBHttpSolrServer.java

@@ -101,6 +101,16 @@ public class LBHttpSolrServer extends SolrServer {
 
   static {
     solrQuery.setRows(0);
+    /**
+     * Default sort (if we don't supply a sort) is by score and since
+     * we request 0 rows any sorting and scoring is not necessary.
+     * SolrQuery.DOCID schema-independently specifies a non-scoring sort.
+     * <code>_docid_ asc</code> sort is efficient,
+     * <code>_docid_ desc</code> sort is not, so choose ascending DOCID sort.
+     */
+    solrQuery.setSort(SolrQuery.DOCID, SolrQuery.ORDER.asc);
+    // not a top-level request, we are interested only in the server being sent to i.e. it need not distribute our request to further servers    
+    solrQuery.setDistrib(false);
   }
 
   protected static class ServerWrapper {

solr/solrj/src/java/org/apache/solr/common/params/CommonParams.java

@@ -48,6 +48,9 @@ public interface CommonParams {
   /** query string */
   public static final String Q ="q";
   
+  /** distrib string */
+  public static final String DISTRIB = "distrib";
+  
   /** sort order */
   public static final String SORT ="sort";