SOLR-11614: ReplicaAssigner to use SolrCloudManager

solr/core/src/java/org/apache/solr/cloud/AddReplicaCmd.java

@@ -124,7 +124,7 @@ public class AddReplicaCmd implements OverseerCollectionMessageHandler.Cmd {
         }
       } else {
         node = getNodesForNewReplicas(clusterState, collection, shard, 1, node,
-            ocmh.overseer.getSolrCloudManager(), ocmh.overseer.getCoreContainer()).get(0).nodeName;// TODO: use replica type in this logic too
+            ocmh.overseer.getSolrCloudManager()).get(0).nodeName;// TODO: use replica type in this logic too
       }
     }
     log.info("Node Identified {} for creating new replica", node);

solr/core/src/java/org/apache/solr/cloud/Assign.java

@@ -32,12 +32,12 @@ import java.util.stream.Collectors;
 
 import com.google.common.collect.ImmutableMap;
 import org.apache.solr.client.solrj.cloud.autoscaling.AlreadyExistsException;
+import org.apache.solr.client.solrj.cloud.autoscaling.AutoScalingConfig;
 import org.apache.solr.client.solrj.cloud.autoscaling.BadVersionException;
 import org.apache.solr.client.solrj.cloud.autoscaling.DistribStateManager;
 import org.apache.solr.client.solrj.cloud.autoscaling.PolicyHelper;
 import org.apache.solr.client.solrj.cloud.autoscaling.SolrCloudManager;
 import org.apache.solr.client.solrj.cloud.autoscaling.VersionedData;
-import org.apache.solr.client.solrj.cloud.autoscaling.AutoScalingConfig;
 import org.apache.solr.cloud.rule.ReplicaAssigner;
 import org.apache.solr.cloud.rule.Rule;
 import org.apache.solr.common.SolrException;
@@ -49,7 +49,6 @@ import org.apache.solr.common.cloud.Slice;
 import org.apache.solr.common.cloud.ZkNodeProps;
 import org.apache.solr.common.util.StrUtils;
 import org.apache.solr.common.util.Utils;
-import org.apache.solr.core.CoreContainer;
 import org.apache.solr.util.NumberUtils;
 import org.apache.zookeeper.CreateMode;
 import org.apache.zookeeper.KeeperException;
@@ -284,7 +283,7 @@ public class Assign {
           (List<Map>) message.get(SNITCH),
           new HashMap<>(),//this is a new collection. So, there are no nodes in any shard
           nodeList,
-          ocmh.overseer.getZkController().getCoreContainer(),
+          ocmh.overseer.getSolrCloudManager(),
           clusterState);
 
       Map<ReplicaPosition, String> nodeMappings = replicaAssigner.getNodeMappings();
@@ -327,7 +326,7 @@ public class Assign {
   // could be created on live nodes given maxShardsPerNode, Replication factor (if from createShard) etc.
   public static List<ReplicaCount> getNodesForNewReplicas(ClusterState clusterState, String collectionName,
                                                           String shard, int nrtReplicas,
-                                                          Object createNodeSet, SolrCloudManager cloudManager, CoreContainer cc) throws IOException, InterruptedException {
+                                                          Object createNodeSet, SolrCloudManager cloudManager) throws IOException, InterruptedException {
     log.debug("getNodesForNewReplicas() shard: {} , replicas : {} , createNodeSet {}", shard, nrtReplicas, createNodeSet );
     DocCollection coll = clusterState.getCollection(collectionName);
     Integer maxShardsPerNode = coll.getMaxShardsPerNode();
@@ -360,7 +359,7 @@ public class Assign {
     List<ReplicaPosition> replicaPositions = null;
     if (l != null) {
       // TODO: make it so that this method doesn't require access to CC
-      replicaPositions = getNodesViaRules(clusterState, shard, nrtReplicas, cc, coll, createNodeList, l);
+      replicaPositions = getNodesViaRules(clusterState, shard, nrtReplicas, cloudManager, coll, createNodeList, l);
     }
     String policyName = coll.getStr(POLICY);
     AutoScalingConfig autoScalingConfig = cloudManager.getDistribStateManager().getAutoScalingConfig();
@@ -417,7 +416,7 @@ public class Assign {
   }
 
   private static List<ReplicaPosition> getNodesViaRules(ClusterState clusterState, String shard, int numberOfNodes,
-                                                        CoreContainer cc, DocCollection coll, List<String> createNodeList, List l) {
+                                                        SolrCloudManager cloudManager, DocCollection coll, List<String> createNodeList, List l) {
     ArrayList<Rule> rules = new ArrayList<>();
     for (Object o : l) rules.add(new Rule((Map) o));
     Map<String, Map<String, Integer>> shardVsNodes = new LinkedHashMap<>();
@@ -439,7 +438,7 @@ public class Assign {
         Collections.singletonMap(shard, numberOfNodes),
         snitches,
         shardVsNodes,
-        nodesList, cc, clusterState).getNodeMappings();
+        nodesList, cloudManager, clusterState).getNodeMappings();
 
     return positions.entrySet().stream().map(e -> e.getKey().setNode(e.getValue())).collect(Collectors.toList());// getReplicaCounts(positions);
   }

solr/core/src/java/org/apache/solr/cloud/CreateShardCmd.java

@@ -105,7 +105,7 @@ public class CreateShardCmd implements Cmd {
             numPullReplicas);
       } else {
         List<Assign.ReplicaCount> sortedNodeList = getNodesForNewReplicas(clusterState, collectionName, sliceName, totalReplicas,
-            createNodeSetStr, ocmh.overseer.getSolrCloudManager(), ocmh.overseer.getCoreContainer());
+            createNodeSetStr, ocmh.overseer.getSolrCloudManager());
         int i = 0;
         positions = new ArrayList<>();
         for (Map.Entry<Replica.Type, Integer> e : ImmutableMap.of(Replica.Type.NRT, numNrtReplicas,

solr/core/src/java/org/apache/solr/cloud/rule/ReplicaAssigner.java

@@ -30,23 +30,27 @@ import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.apache.solr.client.solrj.cloud.autoscaling.SolrCloudManager;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.cloud.ClusterState;
 import org.apache.solr.common.cloud.DocCollection;
-import org.apache.solr.common.cloud.ReplicaPosition;
 import org.apache.solr.common.cloud.Replica;
+import org.apache.solr.common.cloud.ReplicaPosition;
 import org.apache.solr.common.cloud.Slice;
 import org.apache.solr.common.cloud.rule.ImplicitSnitch;
 import org.apache.solr.common.cloud.rule.Snitch;
 import org.apache.solr.common.cloud.rule.SnitchContext;
 import org.apache.solr.common.util.Utils;
-import org.apache.solr.core.CoreContainer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import static java.util.Collections.singletonList;
-import static org.apache.solr.cloud.rule.Rule.MatchStatus.*;
+import static org.apache.solr.cloud.rule.Rule.MatchStatus.NODE_CAN_BE_ASSIGNED;
-import static org.apache.solr.cloud.rule.Rule.Phase.*;
+import static org.apache.solr.cloud.rule.Rule.MatchStatus.NOT_APPLICABLE;
+import static org.apache.solr.cloud.rule.Rule.Phase.ASSIGN;
+import static org.apache.solr.cloud.rule.Rule.Phase.FUZZY_ASSIGN;
+import static org.apache.solr.cloud.rule.Rule.Phase.FUZZY_VERIFY;
+import static org.apache.solr.cloud.rule.Rule.Phase.VERIFY;
 import static org.apache.solr.common.util.Utils.getDeepCopy;
 
 public class ReplicaAssigner {
@@ -71,12 +75,12 @@ public class ReplicaAssigner {
                          List snitches,
                          Map<String, Map<String, Integer>> shardVsNodes,
                          List<String> participatingLiveNodes,
-                         CoreContainer cc, ClusterState clusterState) {
+                         SolrCloudManager cloudManager, ClusterState clusterState) {
     this.rules = rules;
     for (Rule rule : rules) tagNames.add(rule.tag.name);
     this.shardVsReplicaCount = shardVsReplicaCount;
     this.participatingLiveNodes = new ArrayList<>(participatingLiveNodes);
-    this.nodeVsTags = getTagsForNodes(cc, snitches);
+    this.nodeVsTags = getTagsForNodes(cloudManager, snitches);
     this.shardVsNodes = getDeepCopy(shardVsNodes, 2);
 
     if (clusterState != null) {
@@ -309,12 +313,12 @@ public class ReplicaAssigner {
     final Snitch snitch;
     final Set<String> myTags = new HashSet<>();
     final Map<String, SnitchContext> nodeVsContext = new HashMap<>();
-    private final CoreContainer cc;
+    private final SolrCloudManager cloudManager;
 
-    SnitchInfoImpl(Map<String, Object> conf, Snitch snitch, CoreContainer cc) {
+    SnitchInfoImpl(Map<String, Object> conf, Snitch snitch, SolrCloudManager cloudManager) {
       super(conf);
       this.snitch = snitch;
-      this.cc = cc;
+      this.cloudManager = cloudManager;
     }
 
     @Override
@@ -328,13 +332,13 @@ public class ReplicaAssigner {
   /**
    * This method uses the snitches and get the tags for all the nodes
    */
-  private Map<String, Map<String, Object>> getTagsForNodes(final CoreContainer cc, List snitchConf) {
+  private Map<String, Map<String, Object>> getTagsForNodes(final SolrCloudManager cloudManager, List snitchConf) {
 
-    Map<Class, SnitchInfoImpl> snitches = getSnitchInfos(cc, snitchConf);
+    Map<Class, SnitchInfoImpl> snitches = getSnitchInfos(cloudManager, snitchConf);
     for (Class c : Snitch.WELL_KNOWN_SNITCHES) {
       if (snitches.containsKey(c)) continue;// it is already specified explicitly , ignore
       try {
-        snitches.put(c, new SnitchInfoImpl(Collections.EMPTY_MAP, (Snitch) c.newInstance(), cc));
+        snitches.put(c, new SnitchInfoImpl(Collections.EMPTY_MAP, (Snitch) c.newInstance(), cloudManager));
       } catch (Exception e) {
         throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Error instantiating Snitch " + c.getName());
       }
@@ -358,7 +362,7 @@ public class ReplicaAssigner {
       //now use the Snitch to get the tags
       for (SnitchInfoImpl info : snitches.values()) {
         if (!info.myTags.isEmpty()) {
-          SnitchContext context = getSnitchCtx(node, info, cc);
+          SnitchContext context = getSnitchCtx(node, info, cloudManager);
           info.nodeVsContext.put(node, context);
           try {
             info.snitch.getTags(node, info.myTags, context);
@@ -401,16 +405,16 @@ public class ReplicaAssigner {
 
   private Map<String, Object> snitchSession = new HashMap<>();
 
-  protected SnitchContext getSnitchCtx(String node, SnitchInfoImpl info, CoreContainer cc) {
+  protected SnitchContext getSnitchCtx(String node, SnitchInfoImpl info, SolrCloudManager cloudManager) {
-    return new ServerSnitchContext(info, node, snitchSession, cc);
+    return new ServerSnitchContext(info, node, snitchSession, cloudManager);
   }
 
-  public static void verifySnitchConf(CoreContainer cc, List snitchConf) {
+  public static void verifySnitchConf(SolrCloudManager cloudManager, List snitchConf) {
-    getSnitchInfos(cc, snitchConf);
+    getSnitchInfos(cloudManager, snitchConf);
   }
 
 
-  static Map<Class, SnitchInfoImpl> getSnitchInfos(CoreContainer cc, List snitchConf) {
+  static Map<Class, SnitchInfoImpl> getSnitchInfos(SolrCloudManager cloudManager, List snitchConf) {
     if (snitchConf == null) snitchConf = Collections.emptyList();
     Map<Class, SnitchInfoImpl> snitches = new LinkedHashMap<>();
     for (Object o : snitchConf) {
@@ -428,10 +432,9 @@ public class ReplicaAssigner {
       }
       try {
         if (klas.indexOf('.') == -1) klas = Snitch.class.getPackage().getName() + "." + klas;
-        Snitch inst = cc == null ?
+        Snitch inst =
-            (Snitch) Snitch.class.getClassLoader().loadClass(klas).newInstance() :
+            (Snitch) Snitch.class.getClassLoader().loadClass(klas).newInstance() ;
-            cc.getResourceLoader().newInstance(klas, Snitch.class);
+        snitches.put(inst.getClass(), new SnitchInfoImpl(map, inst, cloudManager));
-        snitches.put(inst.getClass(), new SnitchInfoImpl(map, inst, cc));
       } catch (Exception e) {
         throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e);
 

solr/core/src/java/org/apache/solr/cloud/rule/Rule.java

@@ -25,7 +25,6 @@ import org.apache.solr.common.SolrException;
 import org.apache.solr.common.util.StrUtils;
 import org.apache.solr.common.util.Utils;
 
-import static org.apache.solr.common.cloud.rule.ImplicitSnitch.CORES;
 import static org.apache.solr.cloud.rule.Rule.MatchStatus.CANNOT_ASSIGN_FAIL;
 import static org.apache.solr.cloud.rule.Rule.MatchStatus.NODE_CAN_BE_ASSIGNED;
 import static org.apache.solr.cloud.rule.Rule.MatchStatus.NOT_APPLICABLE;
@@ -35,6 +34,7 @@ import static org.apache.solr.cloud.rule.Rule.Operand.LESS_THAN;
 import static org.apache.solr.cloud.rule.Rule.Operand.NOT_EQUAL;
 import static org.apache.solr.common.cloud.ZkStateReader.REPLICA_PROP;
 import static org.apache.solr.common.cloud.ZkStateReader.SHARD_ID_PROP;
+import static org.apache.solr.common.cloud.rule.ImplicitSnitch.CORES;
 
 
 public class Rule {
@@ -73,7 +73,8 @@ public class Rule {
     if (o == null) return o;
     if (typ == String.class) return String.valueOf(o);
     if (typ == Integer.class) {
-      return Integer.parseInt(String.valueOf(o));
+      Double v = Double.parseDouble(String.valueOf(o));
+      return v.intValue();
     }
     return o;
   }

solr/core/src/java/org/apache/solr/cloud/rule/ServerSnitchContext.java

@@ -19,83 +19,40 @@ package org.apache.solr.cloud.rule;
 
 import java.io.IOException;
 import java.lang.invoke.MethodHandles;
-import java.util.Collections;
+import java.util.Collection;
 import java.util.Map;
 
-import org.apache.solr.client.solrj.SolrRequest;
+import org.apache.solr.client.solrj.cloud.autoscaling.SolrCloudManager;
-import org.apache.solr.client.solrj.SolrServerException;
-import org.apache.solr.client.solrj.impl.BinaryResponseParser;
-import org.apache.solr.client.solrj.impl.HttpSolrClient;
-import org.apache.solr.client.solrj.request.GenericSolrRequest;
-import org.apache.solr.client.solrj.response.SimpleSolrResponse;
-import org.apache.solr.common.cloud.rule.RemoteCallback;
 import org.apache.solr.common.cloud.rule.SnitchContext;
-import org.apache.solr.common.params.CommonParams;
-import org.apache.solr.common.params.ModifiableSolrParams;
-import org.apache.solr.common.params.SolrParams;
-import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.Utils;
-import org.apache.solr.core.CoreContainer;
-import org.apache.solr.update.UpdateShardHandler;
 import org.apache.zookeeper.KeeperException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static org.apache.solr.common.params.CoreAdminParams.ACTION;
-import static org.apache.solr.common.params.CoreAdminParams.CoreAdminAction.INVOKE;
-
 public class ServerSnitchContext extends SnitchContext {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
-  final CoreContainer coreContainer;
+  SolrCloudManager cloudManager;
   public ServerSnitchContext(SnitchInfo perSnitch,
                              String node, Map<String, Object> session,
-                             CoreContainer coreContainer) {
+                             SolrCloudManager cloudManager) {
     super(perSnitch, node, session);
-    this.coreContainer = coreContainer;
+    this.cloudManager = cloudManager;
   }
 
 
   public Map getZkJson(String path) throws KeeperException, InterruptedException {
-    if (coreContainer.isZooKeeperAware()) {
-      return Utils.getJson(coreContainer.getZkController().getZkClient(), path, true);
-    } else {
-      return Collections.emptyMap();
-    }
-  }
-
-  public void invokeRemote(String node, ModifiableSolrParams params, String klas, RemoteCallback callback) {
-    if (callback == null) callback = this;
-    params.add("class", klas);
-    params.add(ACTION, INVOKE.toString());
-    //todo batch all requests to the same server
-
     try {
-      SimpleSolrResponse rsp = invoke(node, CommonParams.CORES_HANDLER_PATH, params);
+      return Utils.getJson(cloudManager.getDistribStateManager(), path) ;
-      Map<String, Object> returnedVal = (Map<String, Object>) rsp.getResponse().get(klas);
+    } catch (IOException e) {
-      if(exception == null){
+      throw new RuntimeException(e);
-//        log this
-      } else {
-        callback.remoteCallback(ServerSnitchContext.this,returnedVal);
-      }
-      callback.remoteCallback(this, returnedVal);
-    } catch (Exception e) {
-      log.error("Unable to invoke snitch counterpart", e);
-      exception = e;
     }
+
   }
 
-  public SimpleSolrResponse invoke(String solrNode, String path, SolrParams params)
+  public Map<String, Object> getNodeValues(String node, Collection<String> tags){
-      throws IOException, SolrServerException {
+    return cloudManager.getNodeStateProvider().getNodeValues(node, tags);
-    String url = coreContainer.getZkController().getZkStateReader().getBaseUrlForNodeName(solrNode);
-    UpdateShardHandler shardHandler = coreContainer.getUpdateShardHandler();
-    GenericSolrRequest request = new GenericSolrRequest(SolrRequest.METHOD.GET, path, params);
-    try (HttpSolrClient client = new HttpSolrClient.Builder(url).withHttpClient(shardHandler.getHttpClient())
-        .withResponseParser(new BinaryResponseParser()).build()) {
-      NamedList<Object> rsp = client.request(request);
-      request.response.nl = rsp;
-      return request.response;
-    }
   }
 
+
 }

solr/core/src/java/org/apache/solr/handler/admin/CollectionsHandler.java

@@ -1103,7 +1103,8 @@ public class CollectionsHandler extends RequestHandlerBase implements Permission
         }
       }
     }
-    ReplicaAssigner.verifySnitchConf(cc, (List) m.get(SNITCH));
+    if (cc != null && cc.isZooKeeperAware())
+      ReplicaAssigner.verifySnitchConf(cc.getZkController().getSolrCloudManager(), (List) m.get(SNITCH));
   }
 
   /**

solr/core/src/test/org/apache/solr/cloud/rule/ImplicitSnitchTest.java

@@ -17,6 +17,7 @@
 
 package org.apache.solr.cloud.rule;
 
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -27,9 +28,7 @@ import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.cloud.ZkStateReader;
 import org.apache.solr.common.cloud.rule.ImplicitSnitch;
-import org.apache.solr.common.cloud.rule.RemoteCallback;
 import org.apache.solr.common.cloud.rule.SnitchContext;
-import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.zookeeper.KeeperException;
 import org.junit.Before;
 import org.junit.Test;
@@ -226,8 +225,9 @@ public class ImplicitSnitchTest extends LuceneTestCase {
     expectThrows(SolrException.class, KeeperException.ConnectionLossException.class, () -> implicitSnitch.getTags("", Collections.singleton(ImplicitSnitch.NODEROLE), keeperExceptionSnitch));
 
     ServerSnitchContext remoteExceptionSnitch = new ServerSnitchContext(null, null, new HashMap<>(), null)  {
+
       @Override
-      public void invokeRemote(String node, ModifiableSolrParams params, String klas, RemoteCallback callback) {
+      public Map<String, Object> getNodeValues(String node, Collection<String> tags) {
         throw new RuntimeException();
       }
     };

solr/core/src/test/org/apache/solr/cloud/rule/RuleEngineTest.java

@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -28,12 +29,15 @@ import java.util.Set;
 
 import com.google.common.collect.ImmutableList;
 import org.apache.solr.SolrTestCaseJ4;
+import org.apache.solr.client.solrj.cloud.autoscaling.DelegatingCloudManager;
+import org.apache.solr.client.solrj.cloud.autoscaling.NodeStateProvider;
+import org.apache.solr.client.solrj.cloud.autoscaling.ReplicaInfo;
+import org.apache.solr.client.solrj.cloud.autoscaling.SolrCloudManager;
 import org.apache.solr.common.cloud.ReplicaPosition;
 import org.apache.solr.common.cloud.ZkStateReader;
 import org.apache.solr.common.cloud.rule.Snitch;
 import org.apache.solr.common.cloud.rule.SnitchContext;
 import org.apache.solr.common.util.Utils;
-import org.apache.solr.core.CoreContainer;
 import org.junit.Test;
 
 import static java.util.Collections.singletonList;
@@ -94,8 +98,8 @@ public class RuleEngineTest extends SolrTestCaseJ4{
         new HashMap(), new ArrayList<>(MockSnitch.nodeVsTags.keySet()), null, null) {
 
       @Override
-      protected SnitchContext getSnitchCtx(String node, SnitchInfoImpl info, CoreContainer cc) {
+      protected SnitchContext getSnitchCtx(String node, SnitchInfoImpl info, SolrCloudManager cloudManager) {
-        return new ServerSnitchContext(info, node, snitchSession,cc){
+        return new ServerSnitchContext(info, node, snitchSession,cloudManager){
           @Override
           public Map getZkJson(String path) {
             if(ZkStateReader.ROLES.equals(path)){
@@ -189,6 +193,29 @@ public class RuleEngineTest extends SolrTestCaseJ4{
         new HashMap(), new ArrayList<>(MockSnitch.nodeVsTags.keySet()), null, null).getNodeMappings();
     assertNotNull(mapping);
 
+    mapping = new ReplicaAssigner(
+        rules,
+        shardVsReplicaCount, Collections.emptyList(),
+        new HashMap(), new ArrayList<>(MockSnitch.nodeVsTags.keySet()), new DelegatingCloudManager(null){
+      @Override
+      public NodeStateProvider getNodeStateProvider() {
+        return new NodeStateProvider() {
+          @Override
+          public Map<String, Object> getNodeValues(String node, Collection<String> tags) {
+            return (Map<String, Object>) MockSnitch.nodeVsTags.get(node);
+          }
+
+          @Override
+          public Map<String, Map<String, List<ReplicaInfo>>> getReplicaInfo(String node, Collection<String> keys) {
+            return null;
+          }
+        };
+      }
+    }, null).getNodeMappings();
+    assertNotNull(mapping);
+
+
+
     rules = parseRules(
         "[{cores:'<4'}, " +
             "{replica:'1',shard:'**',host:'*'}]"

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

@@ -43,7 +43,6 @@ import org.apache.solr.common.cloud.ClusterState;
 import org.apache.solr.common.cloud.DocCollection;
 import org.apache.solr.common.cloud.ZkStateReader;
 import org.apache.solr.common.cloud.rule.ImplicitSnitch;
-import org.apache.solr.common.cloud.rule.RemoteCallback;
 import org.apache.solr.common.cloud.rule.SnitchContext;
 import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.params.ModifiableSolrParams;
@@ -247,9 +246,6 @@ public class SolrClientNodeStateProvider implements NodeStateProvider, MapWriter
       return Utils.getJson(zkClientClusterStateProvider.getZkStateReader().getZkClient(), path, true);
     }
 
-    public void invokeRemote(String node, ModifiableSolrParams params, String klas, RemoteCallback callback) {
-
-    }
 
     public SimpleSolrResponse invoke(String solrNode, String path, SolrParams params)
         throws IOException, SolrServerException {

solr/solrj/src/java/org/apache/solr/common/cloud/rule/ImplicitSnitch.java

@@ -21,6 +21,7 @@ import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -30,7 +31,6 @@ import java.util.regex.Pattern;
 
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.cloud.ZkStateReader;
-import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.zookeeper.KeeperException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -79,13 +79,20 @@ public class ImplicitSnitch extends Snitch {
   }
 
   protected void getRemoteInfo(String solrNode, Set<String> requestedTags, SnitchContext ctx) {
-    ModifiableSolrParams params = new ModifiableSolrParams();
+    HashMap<String, Object> params = new HashMap<>();
-    if (requestedTags.contains(CORES)) params.add(CORES, "1");
+    if (requestedTags.contains(CORES)) params.put(CORES, "1");
-    if (requestedTags.contains(DISK)) params.add(DISK, "1");
+    if (requestedTags.contains(DISK)) params.put(DISK, "1");
     for (String tag : requestedTags) {
-      if (tag.startsWith(SYSPROP)) params.add(SYSPROP, tag.substring(SYSPROP.length()));
+      if (tag.startsWith(SYSPROP)) params.put(tag, tag.substring(SYSPROP.length()));
     }
-    if (params.size() > 0) ctx.invokeRemote(solrNode, params, "org.apache.solr.cloud.rule.ImplicitSnitch", null);
+
+    if (params.size() > 0) {
+      Map<String, Object> vals = ctx.getNodeValues(solrNode, params.keySet());
+      for (Map.Entry<String, Object> e : vals.entrySet()) {
+        if(e.getValue() != null) params.put(e.getKey(), e.getValue());
+      }
+    }
+    ctx.getTags().putAll(params);
   }
 
   private void fillRole(String solrNode, SnitchContext ctx, String key) throws KeeperException, InterruptedException {

solr/solrj/src/java/org/apache/solr/common/cloud/rule/SnitchContext.java

@@ -17,6 +17,8 @@
 package org.apache.solr.common.cloud.rule;
 
 import java.lang.invoke.MethodHandles;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
@@ -58,6 +60,9 @@ public abstract class SnitchContext implements RemoteCallback {
     return session != null ? session.get(s) : null;
 
   }
+  public Map<String, Object> getNodeValues(String node, Collection<String> tags){
+    return Collections.emptyMap();
+  }
 
   public abstract Map getZkJson(String path) throws KeeperException, InterruptedException;
 
@@ -75,7 +80,8 @@ public abstract class SnitchContext implements RemoteCallback {
    * @param callback The callback to be called when the response is obtained from remote node.
    *                 If this is passed as null the entire response map will be added as tags
    */
-  public abstract void invokeRemote(String node, ModifiableSolrParams params, String klas, RemoteCallback callback) ;
+  @Deprecated
+  public void invokeRemote(String node, ModifiableSolrParams params, String klas, RemoteCallback callback) {};
 
 
   @Override

solr/solrj/src/java/org/apache/solr/common/util/Utils.java

@@ -40,6 +40,8 @@ import java.util.regex.Pattern;
 
 import org.apache.http.HttpEntity;
 import org.apache.http.util.EntityUtils;
+import org.apache.solr.client.solrj.cloud.autoscaling.DistribStateManager;
+import org.apache.solr.client.solrj.cloud.autoscaling.VersionedData;
 import org.apache.solr.client.solrj.impl.BinaryRequestWriter;
 import org.apache.solr.common.IteratorWriter;
 import org.apache.solr.common.MapWriter;
@@ -366,6 +368,17 @@ public class Utils {
     while (is.read() != -1) {}
   }
 
+  public static Map<String, Object> getJson(DistribStateManager distribStateManager, String path) throws InterruptedException, IOException, KeeperException {
+    VersionedData data = null;
+    try {
+      data = distribStateManager.getData(path);
+    } catch (KeeperException.NoNodeException e) {
+      return Collections.emptyMap();
+    }
+    if (data == null || data.getData() == null || data.getData().length == 0) return Collections.emptyMap();
+    return (Map<String, Object>) Utils.fromJSON(data.getData());
+  }
+
   /**
    * Assumes data in ZooKeeper is a JSON string, deserializes it and returns as a Map
    *