SOLR-14652: SolrCore should hold its own CoreDescriptor (#1675)

(minor refactoring)
Also:
* SolrCore's constructors don't need a "name" since it's guaranteed to always be the name in the coreDescriptor.  I checked.
* SolrCore's constructor shouldn't call coreContainer.solrCores.addCoreDescriptor(cd); because it's the container's responsibility to manage such things.  I made SolrCores.putCore ensure the descriptor is added, and this is called by CoreContainer.registerCore which is called after new SolrCore instances are created.
* solrCore.setName should only be called when we expect the name to change.  Furthermore that shouldn't ever happen in SolrCloud so I added checks.
* solrCore.setName calls coreMetricManager.afterCoreSetName() which is something that is really only related to a rename, not name initialization (from the constructor).  I renamed that method and further only call it if the name did change from non-null.

solr/core/src/java/org/apache/solr/core/CoreContainer.java

@@ -1166,13 +1166,10 @@ public class CoreContainer {
       core.close();
       throw new IllegalStateException("This CoreContainer has been closed");
     }
-    SolrCore old = solrCores.putCore(cd, core);
-    /*
-     * set both the name of the descriptor and the name of the
-     * core, since the descriptors name is used for persisting.
-     */
 
-    core.setName(cd.getName());
+    assert core.getName().equals(cd.getName()) : "core name " + core.getName() + " != cd " + cd.getName();
+
+    SolrCore old = solrCores.putCore(cd, core);
 
     coreInitFailures.remove(cd.getName());
 
@@ -1693,6 +1690,7 @@ public class CoreContainer {
    * Swaps two SolrCore descriptors.
    */
   public void swap(String n0, String n1) {
+    apiAssumeStandalone();
     if (n0 == null || n1 == null) {
       throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Can not swap unnamed cores.");
     }
@@ -1788,6 +1786,7 @@ public class CoreContainer {
   }
 
   public void rename(String name, String toName) {
+    apiAssumeStandalone();
     SolrIdentifierValidator.validateCoreName(toName);
     try (SolrCore core = getCore(name)) {
       if (core != null) {
@@ -1808,6 +1807,12 @@ public class CoreContainer {
     }
   }
 
+  private void apiAssumeStandalone() {
+    if (getZkController() != null) {
+      throw new SolrException(ErrorCode.BAD_REQUEST, "Not supported in SolrCloud");
+    }
+  }
+
   /**
    * Get the CoreDescriptors for all cores managed by this container
    *

solr/core/src/java/org/apache/solr/core/SolrCore.java

@@ -199,6 +199,8 @@ public final class SolrCore implements SolrInfoBean, Closeable {
 
   private boolean isReloaded = false;
 
+  private final CoreDescriptor coreDescriptor;
+  private final CoreContainer coreContainer;
   private final SolrConfig solrConfig;
   private final SolrResourceLoader resourceLoader;
   private volatile IndexSchema schema;
@@ -239,7 +241,6 @@ public final class SolrCore implements SolrInfoBean, Closeable {
   private Counter newSearcherCounter;
   private Counter newSearcherMaxReachedCounter;
   private Counter newSearcherOtherErrorsCounter;
-  private final CoreContainer coreContainer;
 
   private Set<String> metricNames = ConcurrentHashMap.newKeySet();
   private final String metricTag = SolrMetricProducer.getUniqueMetricTag(this, null);
@@ -497,10 +498,13 @@ public final class SolrCore implements SolrInfoBean, Closeable {
   }
 
   public void setName(String v) {
+    Objects.requireNonNull(v);
+    boolean renamed = this.name != null && !this.name.equals(v);
+    assert !renamed || coreDescriptor.getCloudDescriptor() == null : "Cores are not renamed in SolrCloud";
     this.name = v;
-    this.logid = (v == null) ? "" : ("[" + v + "] ");
+    this.logid = "[" + v + "] "; // TODO remove; obsoleted by MDC
-    if (coreMetricManager != null) {
+    if (renamed && coreMetricManager != null) {
-      coreMetricManager.afterCoreSetName();
+      coreMetricManager.afterCoreRename();
     }
   }
 
@@ -706,7 +710,7 @@ public final class SolrCore implements SolrInfoBean, Closeable {
       try {
         CoreDescriptor cd = new CoreDescriptor(name, getCoreDescriptor());
         cd.loadExtraProperties(); //Reload the extra properties
-        core = new SolrCore(coreContainer, getName(), coreConfig, cd, getDataDir(),
+        core = new SolrCore(coreContainer, cd, coreConfig, getDataDir(),
             updateHandler, solrDelPolicy, currentCore, true);
 
         // we open a new IndexWriter to pick up the latest config
@@ -918,8 +922,8 @@ public final class SolrCore implements SolrInfoBean, Closeable {
     return createReloadedUpdateHandler(className, "Update Handler", updateHandler);
   }
 
-  public SolrCore(CoreContainer coreContainer, CoreDescriptor cd, ConfigSet coreConfig) {
+  public SolrCore(CoreContainer coreContainer, CoreDescriptor cd, ConfigSet configSet) {
-    this(coreContainer, cd.getName(), coreConfig, cd, null,
+    this(coreContainer, cd, configSet, null,
         null, null, null, false);
   }
 
@@ -932,22 +936,18 @@ public final class SolrCore implements SolrInfoBean, Closeable {
    * Creates a new core and register it in the list of cores. If a core with the
    * same name already exists, it will be stopped and replaced by this one.
    */
-  private SolrCore(CoreContainer coreContainer, String name, ConfigSet configSet, CoreDescriptor coreDescriptor,
+  private SolrCore(CoreContainer coreContainer, CoreDescriptor coreDescriptor, ConfigSet configSet,
                    String dataDir, UpdateHandler updateHandler,
                    IndexDeletionPolicyWrapper delPolicy, SolrCore prev, boolean reload) {
 
     assert ObjectReleaseTracker.track(searcherExecutor); // ensure that in unclean shutdown tests we still close this
 
-    this.coreContainer = coreContainer;
-
     final CountDownLatch latch = new CountDownLatch(1);
-
     try {
+      this.coreContainer = coreContainer;
+      this.coreDescriptor = Objects.requireNonNull(coreDescriptor, "coreDescriptor cannot be null");
+      setName(coreDescriptor.getName());
 
-      CoreDescriptor cd = Objects.requireNonNull(coreDescriptor, "coreDescriptor cannot be null");
-      coreContainer.solrCores.addCoreDescriptor(cd);
-
-      setName(name);
       this.solrConfig = configSet.getSolrConfig();
       this.resourceLoader = configSet.getSolrConfig().getResourceLoader();
       this.resourceLoader.core = this;
@@ -2957,7 +2957,7 @@ public final class SolrCore implements SolrInfoBean, Closeable {
   }
 
   public CoreDescriptor getCoreDescriptor() {
-    return coreContainer.getCoreDescriptor(name);
+    return coreDescriptor;
   }
 
   public IndexDeletionPolicyWrapper getDeletionPolicy() {

solr/core/src/java/org/apache/solr/core/SolrCores.java

@@ -158,6 +158,8 @@ class SolrCores {
   //WARNING! This should be the _only_ place you put anything into the list of transient cores!
   protected SolrCore putCore(CoreDescriptor cd, SolrCore core) {
     synchronized (modifyLock) {
+      addCoreDescriptor(cd); // cd must always be registered if we register a core
+
       if (cd.isTransient()) {
         if (getTransientCacheHandler() != null) {
           return getTransientCacheHandler().addCore(cd.getName(), core);

solr/core/src/java/org/apache/solr/metrics/SolrCoreMetricManager.java

@@ -92,10 +92,10 @@ public class SolrCoreMetricManager implements Closeable {
    * are carried over and will be used under the new core name.
    * This method also reloads reporters so that they use the new core name.
    */
-  public void afterCoreSetName() {
+  public void afterCoreRename() {
+    assert core.getCoreDescriptor().getCloudDescriptor() == null;
     String oldRegistryName = solrMetricsContext.getRegistryName();
     String oldLeaderRegistryName = leaderRegistryName;
-    initCloudMode();
     String newRegistryName = createRegistryName(cloudMode, collectionName, shardName, replicaName, core.getName());
     leaderRegistryName = createLeaderRegistryName(cloudMode, collectionName, shardName);
     if (oldRegistryName.equals(newRegistryName)) {