SOLR-2610 -- Add an option to delete index through CoreAdmin UNLOAD action

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1138405 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -251,6 +251,12 @@ Documentation
 
 ==================  3.3.0  ==================
 
+Upgrading from Solr 3.2.0
+----------------------
+The SolrCore's CloseHook API has been changed in a backward-incompatible way.
+Any custom components which use the SolrCore.addCloseHook method will need to
+be modified accordingly.
+
 New Features
 ----------------------
 
@@ -276,6 +282,8 @@ New Features
 * SOLR-1331 -- Added a srcCore parameter to CoreAdminHandler's mergeindexes action
   to merge one or more cores' indexes to a target core (shalin)
 
+* SOLR-2610 -- Add an option to delete index through CoreAdmin UNLOAD action (shalin)
+
 Optimizations
 ----------------------
 

solr/src/common/org/apache/solr/common/params/CoreAdminParams.java

@@ -69,6 +69,9 @@ public interface CoreAdminParams
   /** The shard id in solr cloud */
   public final static String SHARD = "shard";
 
+  /** If you unload a core, delete the index too */
+  public final static String DELETE_INDEX = "deleteIndex";
+
   public enum CoreAdminAction {
     STATUS,  
     LOAD,

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

@@ -18,27 +18,40 @@ package org.apache.solr.core;
 
 
 /**
-    * Interface to request notification when the core is closed.
- *<p/>
+ * Used to request notification when the core is closed.
+ * <p/>
  * Call {@link org.apache.solr.core.SolrCore#addCloseHook(org.apache.solr.core.CloseHook)} during the {@link org.apache.solr.util.plugin.SolrCoreAware#inform(SolrCore)} method to
  * add a close hook to your object.
  * <p/>
- * The close hook can be useful for releasing objects related to the request handler (for instance, if you have a JDBC DataSource or something like that) 
- *
- *
-  */
+ * The close hook can be useful for releasing objects related to the request handler (for instance, if you have a JDBC DataSource or something like that)
+ */
 
- public interface CloseHook {
-   
-   /**
-    * Method called when the given SolrCore object is closing / shutting down.
-    * <br />
-    *  <b>Important:</b> Keep the method implementation as short as possible. If it were to use any heavy i/o , network connections -
-    *   it might be a better idea to launch in a separate Thread so as to not to block the process of 
-    *   shutting down a given SolrCore instance.   
-    *   
-    * 
-    * @param core SolrCore object that is shutting down / closing
-    */
-   void close( SolrCore core );
- }
+public abstract class CloseHook {
+
+  /**
+   * Method called when the given SolrCore object is closing / shutting down but before the update handler and
+   * searcher(s) are actually closed
+   * <br />
+   * <b>Important:</b> Keep the method implementation as short as possible. If it were to use any heavy i/o , network connections -
+   * it might be a better idea to launch in a separate Thread so as to not to block the process of
+   * shutting down a given SolrCore instance.
+   *
+   * @param core SolrCore object that is shutting down / closing
+   */
+  public abstract void preClose(SolrCore core);
+
+  /**
+   * Method called when the given SolrCore object has been shut down and update handlers and searchers are closed
+   * <br/>
+   * Use this method for post-close clean up operations e.g. deleting the index from disk.
+   * <br/>
+   * <b>The core's passed to the method is already closed and therefore, it's update handler or searcher should *NOT* be used</b>
+   *
+   * <b>Important:</b> Keep the method implementation as short as possible. If it were to use any heavy i/o , network connections -
+   * it might be a better idea to launch in a separate Thread so as to not to block the process of
+   * shutting down a given SolrCore instance.
+   *
+   * @param core
+   */
+  public abstract void postClose(SolrCore core);
+}

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

@@ -654,7 +654,7 @@ public final class SolrCore implements SolrInfoMBean {
     if( closeHooks != null ) {
        for( CloseHook hook : closeHooks ) {
          try {
-           hook.close( this );
+           hook.preClose( this );
          } catch (Throwable e) {
            SolrException.log(log, e);           
          }
@@ -693,7 +693,15 @@ public final class SolrCore implements SolrInfoMBean {
       SolrException.log(log,e);
     }
 
-
+    if( closeHooks != null ) {
+       for( CloseHook hook : closeHooks ) {
+         try {
+           hook.postClose( this );
+         } catch (Throwable e) {
+           SolrException.log(log, e);
+         }
+      }
+    }
   }
 
   /** Current core usage count. */

solr/src/java/org/apache/solr/handler/ReplicationHandler.java

@@ -889,11 +889,15 @@ public class ReplicationHandler extends RequestHandlerBase implements SolrCoreAw
    */
   private void registerCloseHook() {
     core.addCloseHook(new CloseHook() {
-      public void close(SolrCore core) {
+      @Override
+      public void preClose(SolrCore core) {
         if (snapPuller != null) {
           snapPuller.destroy();
         }
       }
+
+      @Override
+      public void postClose(SolrCore core) {}
     });
   }
 

solr/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java

@@ -18,7 +18,6 @@
 package org.apache.solr.handler.admin;
 
 import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.util.IOUtils;
 import org.apache.solr.cloud.CloudDescriptor;
 import org.apache.solr.common.SolrException;
@@ -28,10 +27,7 @@ import org.apache.solr.common.params.SolrParams;
 import org.apache.solr.common.params.UpdateParams;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.SimpleOrderedMap;
-import org.apache.solr.core.CoreContainer;
-import org.apache.solr.core.CoreDescriptor;
-import org.apache.solr.core.SolrCore;
-import org.apache.solr.core.DirectoryFactory;
+import org.apache.solr.core.*;
 import org.apache.solr.handler.RequestHandlerBase;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.request.LocalSolrQueryRequest;
@@ -41,19 +37,19 @@ import org.apache.solr.util.RefCounted;
 import org.apache.solr.update.MergeIndexesCommand;
 import org.apache.solr.update.processor.UpdateRequestProcessor;
 import org.apache.solr.update.processor.UpdateRequestProcessorChain;
-import org.apache.lucene.store.Directory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.Date;
-import java.util.List;
 
 /**
  *
  * @since solr 1.3
  */
 public class CoreAdminHandler extends RequestHandlerBase {
+  protected static Logger log = LoggerFactory.getLogger(CoreAdminHandler.class);
   protected final CoreContainer coreContainer;
 
   public CoreAdminHandler() {
@@ -397,6 +393,23 @@ public class CoreAdminHandler extends RequestHandlerBase {
        throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
               "No such core exists '"+cname+"'");
     }
+    if (params.getBool(CoreAdminParams.DELETE_INDEX, false)) {
+      core.addCloseHook(new CloseHook() {
+        @Override
+        public void preClose(SolrCore core) {}
+
+        @Override
+        public void postClose(SolrCore core) {
+          File dataDir = new File(core.getIndexDir());
+          for (File file : dataDir.listFiles()) {
+            if (!file.delete()) {
+              log.error(file.getAbsolutePath() + " could not be deleted on core unload");
+            }
+          }
+          if (!dataDir.delete()) log.error(dataDir.getAbsolutePath() + " could not be deleted on core unload");
+        }
+      });
+    }
     core.close();
     return coreContainer.isPersistent();
 

solr/src/solrj/org/apache/solr/client/solrj/request/CoreAdminRequest.java

@@ -163,6 +163,30 @@ public class CoreAdminRequest extends SolrRequest
     }
   }
 
+  public static class Unload extends CoreAdminRequest {
+    protected boolean deleteIndex;
+
+    public Unload(boolean deleteIndex) {
+      action = CoreAdminAction.UNLOAD;
+      this.deleteIndex = deleteIndex;
+    }
+
+    public boolean isDeleteIndex() {
+      return deleteIndex;
+    }
+
+    public void setDeleteIndex(boolean deleteIndex) {
+      this.deleteIndex = deleteIndex;
+    }
+
+    @Override
+    public SolrParams getParams() {
+      ModifiableSolrParams params = (ModifiableSolrParams) super.getParams();
+      params.set(CoreAdminParams.DELETE_INDEX, deleteIndex);
+      return params;
+    }
+  }
+
   public CoreAdminRequest()
   {
     super( METHOD.GET, "/admin/cores" );
@@ -244,11 +268,15 @@ public class CoreAdminRequest extends SolrRequest
 
   public static CoreAdminResponse unloadCore( String name, SolrServer server ) throws SolrServerException, IOException
   {
-    CoreAdminRequest req = new CoreAdminRequest();
+    return unloadCore(name, false, server);
+  }
+
+  public static CoreAdminResponse unloadCore( String name, boolean deleteIndex, SolrServer server ) throws SolrServerException, IOException
+  {
+    Unload req = new Unload(deleteIndex);
     req.setCoreName( name );
-    req.setAction( CoreAdminAction.UNLOAD );
     return req.process( server );
-  }  
+  }
 
   public static CoreAdminResponse renameCore(String coreName, String newName, SolrServer server ) throws SolrServerException, IOException
   {

solr/src/test/org/apache/solr/client/solrj/MultiCoreExampleTestBase.java

@@ -23,11 +23,15 @@ import org.apache.solr.client.solrj.request.UpdateRequest;
 import org.apache.solr.client.solrj.request.UpdateRequest.ACTION;
 import org.apache.solr.client.solrj.response.CoreAdminResponse;
 import org.apache.solr.common.SolrInputDocument;
+import org.apache.solr.common.util.NamedList;
 import org.apache.solr.core.CoreContainer;
 import org.apache.solr.core.SolrCore;
+import org.apache.solr.request.SolrRequestInfo;
 import org.apache.solr.util.ExternalPaths;
 import org.junit.Test;
 
+import java.io.File;
+
 
 /**
  *
@@ -161,5 +165,13 @@ public abstract class MultiCoreExampleTestBase extends SolrExampleTestBase
     }
     catch( Exception ex ) {}
     assertEquals( 1, getSolrCore("corefoo").query( new SolrQuery( "id:BBB" ) ).getResults().size() );
+
+    NamedList<Object> response = getSolrCore("corefoo").query(new SolrQuery().setQueryType("/admin/system")).getResponse();
+    NamedList<Object> coreInfo = (NamedList<Object>) response.get("core");
+    String indexDir = (String) ((NamedList<Object>) coreInfo.get("directory")).get("index");
+    // test delete index on core
+    CoreAdminRequest.unloadCore("corefoo", true, coreadmin);
+    File dir = new File(indexDir);
+    assertFalse("Index directory exists after core unload with deleteIndex=true", dir.exists());
   }
 }

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

@@ -207,9 +207,13 @@ class ClosingRequestHandler extends EmptyRequestHandler implements SolrCoreAware
 
   public void inform(SolrCore core) {
     core.addCloseHook( new CloseHook() {
-      public void close(SolrCore core) {
+      @Override
+      public void preClose(SolrCore core) {
         closed = true;
       }
+
+      @Override
+      public void postClose(SolrCore core) {}
     });
   }
 }