SOLR-10446: Making HttpClusterStateProvider work with server that doesn't have LISTALIASES

solr/CHANGES.txt

@@ -164,8 +164,8 @@ New Features
 * SOLR-10446: CloudSolrClient can now be initialized using the base URL of a Solr instance instead of
   ZooKeeper hosts. This is possible through the use of newly introduced HttpClusterStateProvider.
   To fetch a list of collection aliases, this depends on LISTALIASES command, and hence this way of
-  initializing CloudSolrClient would not work with older versions of Solr that doesn't support LISTALIASES.
-  (Ishan Chattopadhyaya, Noble Paul)
+  initializing CloudSolrClient would not work if you have collection aliases on older versions of Solr
+  server that doesn't support LISTALIASES. (Ishan Chattopadhyaya, Noble Paul)
 
 Optimizations
 ----------------------

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

@@ -16,7 +16,6 @@
  */
 package org.apache.solr.client.solrj.impl;
 
-import java.io.Closeable;
 import java.io.IOException;
 import java.lang.invoke.MethodHandles;
 import java.net.ConnectException;
@@ -1783,34 +1782,4 @@ public class CloudSolrClient extends SolrClient {
           shardLeadersOnly, directUpdatesToLeadersOnly, stateProvider);
     }
   }
-
-  interface ClusterStateProvider extends Closeable {
-
-    /**
-     * Obtain the state of the collection (cluster status).
-     * @return the collection state, or null is collection doesn't exist
-     */
-    ClusterState.CollectionRef getState(String collection);
-
-    /**
-     * Obtain set of live_nodes for the cluster.
-     */
-    Set<String> liveNodes();
-
-    String getAlias(String collection);
-
-    String getCollectionName(String name);
-
-    /**
-     * Obtain a cluster property, or null if it doesn't exist.
-     */
-    Object getClusterProperty(String propertyName);
-
-    /**
-     * Obtain a cluster property, or the default value if it doesn't exist.
-     */
-    Object getClusterProperty(String propertyName, String def);
-
-    void connect();
-  }
 }

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

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.solr.client.solrj.impl;
+
+import java.io.Closeable;
+import java.util.Set;
+
+import org.apache.solr.common.cloud.ClusterState;
+
+public interface ClusterStateProvider extends Closeable {
+
+  /**
+   * Obtain the state of the collection (cluster status).
+   * @return the collection state, or null is collection doesn't exist
+   */
+  ClusterState.CollectionRef getState(String collection);
+
+  /**
+   * Obtain set of live_nodes for the cluster.
+   */
+  Set<String> liveNodes();
+
+  /**
+   * Given an alias, returns the collection name that this alias points to
+   */
+  String getAlias(String alias);
+
+  /**
+   * Given a name, returns the collection name if an alias by that name exists, or
+   * returns the name itself, if no alias exists.
+   */
+  String getCollectionName(String name);
+
+  /**
+   * Obtain a cluster property, or null if it doesn't exist.
+   */
+  Object getClusterProperty(String propertyName);
+
+  /**
+   * Obtain a cluster property, or the default value if it doesn't exist.
+   */
+  Object getClusterProperty(String propertyName, String def);
+
+  void connect();
+}

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

@@ -40,7 +40,7 @@ import org.apache.solr.common.util.SimpleOrderedMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class HttpClusterStateProvider implements CloudSolrClient.ClusterStateProvider {
+public class HttpClusterStateProvider implements ClusterStateProvider {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
   private String urlScheme;
@@ -72,8 +72,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
       throw new RuntimeException("Tried fetching live_nodes using Solr URLs provided, i.e. " + solrUrls + ". However, "
           + "succeeded in obtaining the cluster state from none of them."
           + "If you think your Solr cluster is up and is accessible,"
-          + " you could try re-creating a new CloudSolrClient using a working"
-          + " solrUrl or zkUrl.");
+          + " you could try re-creating a new CloudSolrClient using working"
+          + " solrUrl(s) or zkHost(s).");
     }
   }
 
@@ -106,8 +106,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
     throw new RuntimeException("Tried fetching cluster state using the node names we knew of, i.e. " + liveNodes +". However, "
         + "succeeded in obtaining the cluster state from none of them."
         + "If you think your Solr cluster is up and is accessible,"
-        + " you could try re-creating a new CloudSolrClient using a working"
-        + " solrUrl or zkUrl.");
+        + " you could try re-creating a new CloudSolrClient using working"
+        + " solrUrl(s) or zkHost(s).");
   }
 
   @SuppressWarnings({"rawtypes", "unchecked"})
@@ -118,7 +118,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
     QueryRequest request = new QueryRequest(params);
     request.setPath("/admin/collections");
     NamedList cluster = (SimpleOrderedMap) client.request(request).get("cluster");
-    Map<String, Object> collectionsMap = ((NamedList) cluster.get("collections")).asShallowMap();
+    Map<String, Object> collectionsMap = Collections.singletonMap(collection,
+        ((NamedList) cluster.get("collections")).get(collection));
     int znodeVersion = (int)((Map<String, Object>)(collectionsMap).get(collection)).get("znodeVersion");
     Set<String> liveNodes = new HashSet((List<String>)(cluster.get("live_nodes")));
     this.liveNodes = liveNodes;
@@ -133,8 +134,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
       throw new RuntimeException("We don't know of any live_nodes to fetch the"
           + " latest live_nodes information from. "
           + "If you think your Solr cluster is up and is accessible,"
-          + " you could try re-creating a new CloudSolrClient using a working"
-          + " solrUrl or zkUrl.");
+          + " you could try re-creating a new CloudSolrClient using working"
+          + " solrUrl(s) or zkHost(s).");
     }
     if (TimeUnit.SECONDS.convert((System.nanoTime() - liveNodesTimestamp), TimeUnit.NANOSECONDS) > getCacheTimeout()) {
       for (String nodeName: liveNodes) {
@@ -153,8 +154,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
       throw new RuntimeException("Tried fetching live_nodes using all the node names we knew of, i.e. " + liveNodes +". However, "
           + "succeeded in obtaining the cluster state from none of them."
           + "If you think your Solr cluster is up and is accessible,"
-          + " you could try re-creating a new CloudSolrClient using a working"
-          + " solrUrl or zkUrl.");
+          + " you could try re-creating a new CloudSolrClient using working"
+          + " solrUrl(s) or zkHost(s).");
     } else {
       return liveNodes; // cached copy is fresh enough
     }
@@ -171,9 +172,9 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
   }
 
   @Override
-  public String getAlias(String collection) {
+  public String getAlias(String alias) {
     Map<String, String> aliases = getAliases(false);
-    return aliases.get(collection);
+    return aliases.get(alias);
   }
 
   private Map<String, String> getAliases(boolean forceFetch) {
@@ -181,8 +182,8 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
       throw new RuntimeException("We don't know of any live_nodes to fetch the"
           + " latest aliases information from. "
           + "If you think your Solr cluster is up and is accessible,"
-          + " you could try re-creating a new CloudSolrClient using a working"
-          + " solrUrl or zkUrl.");
+          + " you could try re-creating a new CloudSolrClient using working"
+          + " solrUrl(s) or zkHost(s).");
     }
 
     if (forceFetch || this.aliases == null ||
@@ -197,6 +198,14 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
           this.aliasesTimestamp = System.nanoTime();
           return Collections.unmodifiableMap(aliases);
         } catch (SolrServerException | RemoteSolrException | IOException e) {
+          // Situation where we're hitting an older Solr which doesn't have LISTALIASES
+          if (e instanceof RemoteSolrException && ((RemoteSolrException)e).code()==400) {
+            log.warn("LISTALIASES not found, possibly using older Solr server. Aliases won't work"
+                + " unless you re-create the CloudSolrClient using zkHost(s) or upgrade Solr server", e);
+            this.aliases = Collections.emptyMap();
+            this.aliasesTimestamp = System.nanoTime();
+            return aliases;
+          }
           log.warn("Attempt to fetch cluster state from " +
               ZkStateReader.getBaseUrlForNodeName(nodeName, urlScheme) + " failed.", e);
         }
@@ -206,7 +215,7 @@ public class HttpClusterStateProvider implements CloudSolrClient.ClusterStatePro
           + "succeeded in obtaining the cluster state from none of them."
           + "If you think your Solr cluster is up and is accessible,"
           + " you could try re-creating a new CloudSolrClient using a working"
-          + " solrUrl or zkUrl.");
+          + " solrUrl or zkHost.");
     } else {
       return Collections.unmodifiableMap(this.aliases); // cached copy is fresh enough
     }

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

@@ -34,7 +34,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 
-public class ZkClientClusterStateProvider implements CloudSolrClient.ClusterStateProvider {
+public class ZkClientClusterStateProvider implements ClusterStateProvider {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
 
@@ -63,9 +63,9 @@ public class ZkClientClusterStateProvider implements CloudSolrClient.ClusterStat
 
 
   @Override
-  public String getAlias(String collection) {
+  public String getAlias(String alias) {
     Aliases aliases = zkStateReader.getAliases();
-    return aliases.getCollectionAlias(collection);
+    return aliases.getCollectionAlias(alias);
   }
 
   @Override

solr/solrj/src/test/org/apache/solr/client/solrj/impl/CloudSolrClientCacheTest.java

@@ -117,9 +117,9 @@ public class CloudSolrClientCacheTest extends SolrTestCaseJ4 {
     return mockLbclient;
   }
 
-  private CloudSolrClient.ClusterStateProvider getStateProvider(Set<String> livenodes,
+  private ClusterStateProvider getStateProvider(Set<String> livenodes,
                                                                 Map<String, ClusterState.CollectionRef> colls) {
-    return new CloudSolrClient.ClusterStateProvider() {
+    return new ClusterStateProvider() {
       @Override
       public ClusterState.CollectionRef getState(String collection) {
         return colls.get(collection);