SOLR-14000: clean up more static field leaks in tests

On windows, these objects can't be inspected due to security restrictions. So the test runner fails the tests since it does not know how big the leak is.

solr/contrib/prometheus-exporter/src/test/org/apache/solr/prometheus/scraper/SolrStandaloneScraperTest.java

@@ -91,6 +91,8 @@ public class SolrStandaloneScraperTest extends RestTestBase {
       jetty.stop();
       jetty = null;
     }
+    solrScraper = null;
+    solrClient = null;
   }
 
   @Test

solr/core/src/test/org/apache/solr/cloud/OverseerCollectionConfigSetProcessorTest.java

@@ -204,6 +204,7 @@ public class OverseerCollectionConfigSetProcessorTest extends SolrTestCaseJ4 {
     zkControllerMock = null;
     cloudDataProviderMock = null;
     clusterStateProviderMock = null;
+    stateManagerMock = null;;
     cloudManagerMock = null;
     distribStateManagerMock = null;
     coreContainerMock = null;

solr/core/src/test/org/apache/solr/cloud/OverseerTest.java

@@ -315,6 +315,8 @@ public class OverseerTest extends SolrTestCaseJ4 {
     if (null != server) {
       server.shutdown();
     }
+
+    server = null;
   }
 
   @After

solr/core/src/test/org/apache/solr/cloud/TestWithCollection.java

@@ -48,6 +48,7 @@ import org.apache.solr.common.util.TimeSource;
 import org.apache.solr.util.LogLevel;
 import org.apache.solr.util.TimeOut;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -92,6 +93,11 @@ public class TestWithCollection extends SolrCloudTestCase {
     shutdownCluster();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    cloudManager = null;
+  }
+
   private void deleteChildrenRecursively(String path) throws Exception {
     cloudManager.getDistribStateManager().removeRecursively(path, true, false);
   }

solr/core/src/test/org/apache/solr/cloud/autoscaling/ComputePlanActionTest.java

@@ -56,6 +56,7 @@ import org.apache.solr.common.util.Utils;
 import org.apache.solr.core.SolrResourceLoader;
 import org.apache.solr.util.LogLevel;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -168,6 +169,11 @@ public class ComputePlanActionTest extends SolrCloudTestCase {
     state.forEachCollection(coll -> log.debug("* Collection " + coll.getName() + " state: " + coll));
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    cloudManager = null;
+  }
+
   @Test
   @LuceneTestCase.AwaitsFix(bugUrl="https://issues.apache.org/jira/browse/SOLR-12028") 
   public void testNodeLost() throws Exception  {

solr/core/src/test/org/apache/solr/cloud/autoscaling/NodeAddedTriggerIntegrationTest.java

@@ -41,6 +41,7 @@ import org.apache.solr.util.LogLevel;
 import org.apache.solr.util.TimeOut;
 import org.apache.zookeeper.data.Stat;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -68,6 +69,11 @@ public class NodeAddedTriggerIntegrationTest extends SolrCloudTestCase {
     shutdownCluster();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    cloudManager = null;
+  }
+
   private static CountDownLatch getTriggerFiredLatch() {
     return triggerFiredLatch;
   }

solr/core/src/test/org/apache/solr/cloud/autoscaling/NodeLostTriggerIntegrationTest.java

@@ -43,6 +43,7 @@ import org.apache.solr.util.LogLevel;
 import org.apache.solr.util.TimeOut;
 import org.apache.zookeeper.data.Stat;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -116,6 +117,11 @@ public class NodeLostTriggerIntegrationTest extends SolrCloudTestCase {
     shutdownCluster();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    cloudManager = null;
+  }
+
   private void deleteChildrenRecursively(String path) throws Exception {
     cloudManager.getDistribStateManager().removeRecursively(path, true, false);
   }

solr/core/src/test/org/apache/solr/cloud/autoscaling/TriggerIntegrationTest.java

@@ -50,6 +50,7 @@ import org.apache.solr.common.util.Utils;
 import org.apache.solr.core.SolrResourceLoader;
 import org.apache.solr.util.LogLevel;
 import org.apache.zookeeper.data.Stat;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -90,6 +91,11 @@ public class TriggerIntegrationTest extends SolrCloudTestCase {
     CloudTestUtils.suspendTrigger(cluster.getOpenOverseer().getSolrCloudManager(), ".scheduled_maintenance");
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    cloudManager = null;
+  }
+
   private static CountDownLatch getTriggerFiredLatch() {
     return triggerFiredLatch;
   }

solr/core/src/test/org/apache/solr/cloud/autoscaling/sim/TestSimClusterStateProvider.java

@@ -88,6 +88,7 @@ public class TestSimClusterStateProvider extends SolrCloudTestCase {
     if (simulated && cloudManager != null) {
       cloudManager.close();
     }
+    cloudManager = null;
   }
 
   private static void init() throws Exception {

solr/core/src/test/org/apache/solr/cloud/autoscaling/sim/TestSnapshotCloudManager.java

@@ -51,6 +51,7 @@ import org.apache.solr.common.cloud.Replica;
 import org.apache.solr.common.params.CollectionAdminParams;
 import org.apache.solr.common.util.TimeSource;
 import org.apache.solr.common.util.Utils;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -82,6 +83,11 @@ public class TestSnapshotCloudManager extends SolrCloudTestCase {
         .getZkController().getSolrCloudManager();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    realManager = null;
+  }
+
   @Test
   public void testSnapshots() throws Exception {
     SnapshotCloudManager snapshotCloudManager = new SnapshotCloudManager(realManager, null);

solr/core/src/test/org/apache/solr/core/TestJmxIntegration.java

@@ -100,6 +100,7 @@ public class TestJmxIntegration extends SolrTestCaseJ4 {
       MBeanServerFactory.releaseMBeanServer(newMbeanServer);
     }
     mbeanServer = null;
+    newMbeanServer = null;
   }
 
   @Before

solr/core/src/test/org/apache/solr/handler/admin/MetricsHistoryHandlerTest.java

@@ -111,6 +111,11 @@ public class MetricsHistoryHandlerTest extends SolrCloudTestCase {
     if (simulated) {
       cloudManager.close();
     }
+    handler = null;
+    metricsHandler = null;
+    cloudManager = null;
+    metricManager = null;
+    solrClient = null;
   }
 
   @Test

solr/core/src/test/org/apache/solr/handler/tagger/EmbeddedSolrNoSerializeTest.java

@@ -42,6 +42,7 @@ import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.util.ContentStream;
 import org.apache.solr.common.util.ContentStreamBase;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
@@ -62,6 +63,11 @@ public class EmbeddedSolrNoSerializeTest extends SolrTestCaseJ4 {
     //we don't need to close the EmbeddedSolrServer because SolrTestCaseJ4 closes the core
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    solrServer = null;
+  }
+
   @Before
   public void setUp() throws Exception {
     super.setUp();

solr/core/src/test/org/apache/solr/handler/tagger/XmlInterpolationTest.java

@@ -40,6 +40,7 @@ import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.response.SolrQueryResponse;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.xml.sax.InputSource;
@@ -59,6 +60,11 @@ public class XmlInterpolationTest extends TaggerTestCase {
     initCore("solrconfig-tagger.xml", "schema-tagger.xml");
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    xmlDocBuilder = null;
+  }
+
   @Override
   public void setUp() throws Exception {
     super.setUp();

solr/core/src/test/org/apache/solr/search/join/TestCloudNestedDocsSort.java

@@ -36,6 +36,7 @@ import org.apache.solr.cloud.SolrCloudTestCase;
 import org.apache.solr.common.SolrDocument;
 import org.apache.solr.common.SolrInputDocument;
 import org.apache.solr.common.cloud.ZkStateReader;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -120,6 +121,11 @@ public class TestCloudNestedDocsSort extends SolrCloudTestCase {
     }
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    client = null;
+  }
+
   @Test 
   public void test() throws SolrServerException, IOException {
     final boolean asc = random().nextBoolean();

solr/core/src/test/org/apache/solr/update/processor/CategoryRoutedAliasUpdateProcessorTest.java

@@ -40,6 +40,7 @@ import org.apache.solr.response.SolrQueryResponse;
 import org.apache.solr.update.UpdateCommand;
 import org.apache.solr.util.LogLevel;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -85,6 +86,11 @@ public class CategoryRoutedAliasUpdateProcessorTest extends RoutedAliasUpdatePro
     }
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    solrClient = null;
+  }
+
   @Test
   @Slow
   public void testNonEnglish() throws Exception {

solr/core/src/test/org/apache/solr/update/processor/DimensionalRoutedAliasUpdateProcessorTest.java

@@ -85,6 +85,7 @@ public class DimensionalRoutedAliasUpdateProcessorTest extends RoutedAliasUpdate
   @AfterClass
   public static void finish() throws Exception {
     IOUtils.close(solrClient);
+    solrClient = null;
   }
   @Test
   public void testTimeCat() throws Exception {

solr/solrj/src/test/org/apache/solr/client/solrj/impl/CloudHttp2SolrClientTest.java

@@ -71,6 +71,7 @@ import org.apache.solr.handler.admin.CollectionsHandler;
 import org.apache.solr.handler.admin.ConfigSetsHandler;
 import org.apache.solr.handler.admin.CoreAdminHandler;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -134,6 +135,12 @@ public class CloudHttp2SolrClientTest extends SolrCloudTestCase {
     super.tearDown();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    httpBasedCloudSolrClient = null;
+    zkBasedCloudSolrClient = null;
+  }
+
   /**
    * Randomly return the cluster's ZK based CSC, or HttpClusterProvider based CSC.
    */

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

@@ -72,6 +72,7 @@ import org.apache.solr.handler.admin.CollectionsHandler;
 import org.apache.solr.handler.admin.ConfigSetsHandler;
 import org.apache.solr.handler.admin.CoreAdminHandler;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -124,6 +125,11 @@ public class CloudSolrClientTest extends SolrCloudTestCase {
     super.tearDown();
   }
 
+  @AfterClass
+  public static void cleanUpAfterClass() throws Exception {
+    httpBasedCloudSolrClient = null;
+  }
+
   /**
    * Randomly return the cluster's ZK based CSC, or HttpClusterProvider based CSC.
    */