Simplify logic around missing shards check in search phases (elastic#122817) (elastic#122916)

This removes a couple of indirections: the error message for missing shards is always the
same no matter the search phase. This was required to provide a slightly different error
message for open PIT. The previous error was misleading when open PIT did not support
setting allow_partial_search_results, but now that it does, it looks like we can unify
the error message and simplify the code around it.

Author: javanna

server/src/internalClusterTest/java/org/elasticsearch/search/retriever/RetrieverRewriteIT.java

@@ -127,10 +127,7 @@ public void testRewriteCompoundRetrieverShouldThrowForPartialResults() throws Ex
                 SearchPhaseExecutionException.class,
                 client().prepareSearch(testIndex).setSource(source)::get
             );
-            assertThat(
-                ex.getDetailedMessage(),
-                containsString("[open_point_in_time] action requires all shards to be available. Missing shards")
-            );
+            assertThat(ex.getDetailedMessage(), containsString("Search rejected due to missing shards"));
         } finally {
             internalCluster().restartNode(randomDataNode);
         }

server/src/main/java/org/elasticsearch/action/search/SearchPhase.java

@@ -43,13 +43,13 @@ public void start() {
         }
     }
 
-    protected String missingShardsErrorMessage(StringBuilder missingShards) {
+    private static String makeMissingShardsError(StringBuilder missingShards) {
         return "Search rejected due to missing shards ["
             + missingShards
             + "]. Consider using `allow_partial_search_results` setting to bypass this error.";
     }
 
-    protected void doCheckNoMissingShards(String phaseName, SearchRequest request, List<SearchShardIterator> shardsIts) {
+    protected static void doCheckNoMissingShards(String phaseName, SearchRequest request, List<SearchShardIterator> shardsIts) {
         assert request.allowPartialSearchResults() != null : "SearchRequest missing setting for allowPartialSearchResults";
         if (request.allowPartialSearchResults() == false) {
             final StringBuilder missingShards = new StringBuilder();
@@ -65,7 +65,7 @@ protected void doCheckNoMissingShards(String phaseName, SearchRequest request, L
             }
             if (missingShards.isEmpty() == false) {
                 // Status red - shard is missing all copies and would produce partial results for an index search
-                final String msg = missingShardsErrorMessage(missingShards);
+                final String msg = makeMissingShardsError(missingShards);
                 throw new SearchPhaseExecutionException(phaseName, msg, null, ShardSearchFailure.EMPTY_ARRAY);
             }
         }

server/src/main/java/org/elasticsearch/action/search/TransportOpenPointInTimeAction.java

@@ -241,13 +241,6 @@ SearchPhase openPointInTimePhase(
                 searchRequest.getMaxConcurrentShardRequests(),
                 clusters
             ) {
-                @Override
-                protected String missingShardsErrorMessage(StringBuilder missingShards) {
-                    return "[open_point_in_time] action requires all shards to be available. Missing shards: ["
-                        + missingShards
-                        + "].  Consider using `allow_partial_search_results` setting to bypass this error.";
-                }
-
                 @Override
                 protected void executePhaseOnShard(
                     SearchShardIterator shardIt,

x-pack/plugin/sql/qa/jdbc/single-node/src/javaRestTest/java/org/elasticsearch/xpack/sql/qa/jdbc/single_node/JdbcShardFailureIT.java

@@ -76,7 +76,7 @@ public void createTestIndex() throws IOException {
     public void testPartialResponseHandling() throws SQLException {
         try (Connection c = esJdbc(); Statement s = c.createStatement()) {
             SQLException exception = expectThrows(SQLException.class, () -> s.executeQuery("SELECT * FROM test ORDER BY test_field ASC"));
-            assertThat(exception.getMessage(), containsString("[open_point_in_time] action requires all shards to be available"));
+            assertThat(exception.getMessage(), containsString("Search rejected due to missing shards"));
         }
     }
 }

x-pack/plugin/sql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/sql/qa/single_node/JdbcShardFailureIT.java

@@ -89,7 +89,7 @@ public void testPartialResponseHandling() throws Exception {
         createTestIndex();
         try (Connection c = esJdbc(); Statement s = c.createStatement()) {
             SQLException exception = expectThrows(SQLException.class, () -> s.executeQuery("SELECT * FROM test ORDER BY test_field ASC"));
-            assertThat(exception.getMessage(), containsString("[open_point_in_time] action requires all shards to be available"));
+            assertThat(exception.getMessage(), containsString("Search rejected due to missing shards"));
         }
     }