Remove IndexTemplateAlreadyExistsException and IndexShardAlreadyExistsException (#21539)

Both exception can be replaced with java built-in exception, IAE and ISE respectively.
This should be back ported partially to 5.x which the transport layer code should be preserved.

Relates to #21494

Author: s1monw

core/src/main/java/org/elasticsearch/ElasticsearchException.java

@@ -554,7 +554,7 @@ enum ElasticsearchExceptionHandle {
                 org.elasticsearch.common.io.stream.NotSerializableExceptionWrapper::new, 62),
         ALIAS_FILTER_PARSING_EXCEPTION(org.elasticsearch.indices.AliasFilterParsingException.class,
                 org.elasticsearch.indices.AliasFilterParsingException::new, 63),
-        // 64 was DeleteByQueryFailedEngineException, which was removed in 3.0
+        // 64 was DeleteByQueryFailedEngineException, which was removed in 5.0
         GATEWAY_EXCEPTION(org.elasticsearch.gateway.GatewayException.class, org.elasticsearch.gateway.GatewayException::new, 65),
         INDEX_SHARD_NOT_RECOVERING_EXCEPTION(org.elasticsearch.index.shard.IndexShardNotRecoveringException.class,
                 org.elasticsearch.index.shard.IndexShardNotRecoveringException::new, 66),

core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java

@@ -142,7 +142,7 @@ public Integer version() {
 
     /**
      * Set to <tt>true</tt> to force only creation, not an update of an index template. If it already
-     * exists, it will fail with an {@link org.elasticsearch.indices.IndexTemplateAlreadyExistsException}.
+     * exists, it will fail with an {@link IllegalArgumentException}.
      */
     public PutIndexTemplateRequest create(boolean create) {
         this.create = create;

core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java

@@ -67,7 +67,7 @@ public PutIndexTemplateRequestBuilder setVersion(Integer version) {
 
     /**
      * Set to <tt>true</tt> to force only creation, not an update of an index template. If it already
-     * exists, it will fail with an {@link org.elasticsearch.indices.IndexTemplateAlreadyExistsException}.
+     * exists, it will fail with an {@link IllegalArgumentException}.
      */
     public PutIndexTemplateRequestBuilder setCreate(boolean create) {
         request.create(create);

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexTemplateService.java

@@ -40,7 +40,6 @@
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.MapperParsingException;
 import org.elasticsearch.index.mapper.MapperService;
-import org.elasticsearch.indices.IndexTemplateAlreadyExistsException;
 import org.elasticsearch.indices.IndexTemplateMissingException;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.indices.InvalidIndexTemplateException;
@@ -161,7 +160,7 @@ public void onFailure(String source, Exception e) {
             @Override
             public ClusterState execute(ClusterState currentState) throws Exception {
                 if (request.create && currentState.metaData().templates().containsKey(request.name)) {
-                    throw new IndexTemplateAlreadyExistsException(request.name);
+                    throw new IllegalArgumentException("index_template [" + request.name + "] already exists");
                 }
 
                 validateAndAddTemplate(request, templateBuilder, indicesService);

core/src/main/java/org/elasticsearch/index/IndexService.java

@@ -330,7 +330,7 @@ public synchronized IndexShard createShard(ShardRouting routing) throws IOExcept
             }
 
             if (shards.containsKey(shardId.id())) {
-                throw new IndexShardAlreadyExistsException(shardId + " already exists");
+                throw new IllegalStateException(shardId + " already exists");
             }
 
             logger.debug("creating shard_id {}", shardId);

core/src/main/java/org/elasticsearch/index/IndexShardAlreadyExistsException.java

@@ -26,7 +26,9 @@
 
 /**
  *
+ * @deprecated use {@link IllegalStateException} instead
  */
+@Deprecated
 public class IndexShardAlreadyExistsException extends ElasticsearchException {
 
     public IndexShardAlreadyExistsException(String message) {
@@ -36,4 +38,4 @@ public IndexShardAlreadyExistsException(String message) {
     public IndexShardAlreadyExistsException(StreamInput in) throws IOException {
         super(in);
     }
-}
+}

core/src/main/java/org/elasticsearch/indices/IndexTemplateAlreadyExistsException.java

@@ -26,8 +26,9 @@
 import java.io.IOException;
 
 /**
- *
+ * @deprecated use {@link IllegalArgumentException} instead
  */
+@Deprecated
 public class IndexTemplateAlreadyExistsException extends ElasticsearchException {
 
     private final String name;

core/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java

@@ -31,7 +31,6 @@
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
-import org.elasticsearch.cluster.routing.RecoverySource.SnapshotRecoverySource;
 import org.elasticsearch.cluster.routing.RecoverySource.Type;
 import org.elasticsearch.cluster.routing.RoutingNode;
 import org.elasticsearch.cluster.routing.RoutingTable;
@@ -40,7 +39,6 @@
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.component.AbstractLifecycleComponent;
 import org.elasticsearch.common.inject.Inject;
-import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.Callback;
@@ -52,7 +50,6 @@
 import org.elasticsearch.index.IndexComponent;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.IndexSettings;
-import org.elasticsearch.index.IndexShardAlreadyExistsException;
 import org.elasticsearch.index.shard.IndexEventListener;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.shard.IndexShardRelocatedException;
@@ -532,10 +529,6 @@ private void createShard(DiscoveryNodes nodes, RoutingTable routingTable, ShardR
             RecoveryState recoveryState = new RecoveryState(shardRouting, nodes.getLocalNode(), sourceNode);
             indicesService.createShard(shardRouting, recoveryState, recoveryTargetService, new RecoveryListener(shardRouting),
                 repositoriesService, failedShardHandler);
-        } catch (IndexShardAlreadyExistsException e) {
-            // ignore this, the method call can happen several times
-            logger.debug("Trying to create shard that already exists", e);
-            assert false;
         } catch (Exception e) {
             failAndRemoveShard(shardRouting, true, "failed to create shard", e);
         }

core/src/test/java/org/elasticsearch/indices/template/SimpleIndexTemplateIT.java

@@ -34,7 +34,6 @@
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.index.mapper.MapperParsingException;
 import org.elasticsearch.index.query.QueryBuilders;
-import org.elasticsearch.indices.IndexTemplateAlreadyExistsException;
 import org.elasticsearch.indices.InvalidAliasNameException;
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.test.ESIntegTestCase;
@@ -110,7 +109,7 @@ public void testSimpleIndexTemplateTests() throws Exception {
                 .addMapping("type1", XContentFactory.jsonBuilder().startObject().startObject("type1").startObject("properties")
                         .startObject("field2").field("type", "text").field("store", false).endObject()
                         .endObject().endObject().endObject())
-                , IndexTemplateAlreadyExistsException.class
+                , IllegalArgumentException.class
         );
 
         response = client().admin().indices().prepareGetTemplates().get();