Added capability to perform hot backups.

3 files changed, 157 insertions, 4 deletions

diff --git a/src/main/java/com/amazon/carbonado/repo/sleepycat/BDBRepository.java b/src/main/java/com/amazon/carbonado/repo/sleepycat/BDBRepository.java
index 9f3d9ac..01e3668 100644
--- a/src/main/java/com/amazon/carbonado/repo/sleepycat/BDBRepository.java
+++ b/src/main/java/com/amazon/carbonado/repo/sleepycat/BDBRepository.java
@@ -83,6 +83,7 @@ abstract class BDBRepository<Txn> extends AbstractRepository<Txn>
     implements Repository,

                RepositoryAccess,

                IndexInfoCapability,

+               HotBackupCapability,

                CheckpointCapability,

                EnvironmentCapability,

                ShutdownCapability,

@@ -116,6 +117,9 @@ abstract class BDBRepository<Txn> extends AbstractRepository<Txn>
     final String mSingleFileName;

     final Map<String, String> mFileNameMap;

 

+    final Object mBackupLock = new Object();

+    int mBackupCount = 0;

+

     private LayoutFactory mLayoutFactory;

 

     private LobEngine mLobEngine;

@@ -221,6 +225,63 @@ abstract class BDBRepository<Txn> extends AbstractRepository<Txn>
         return StorableIntrospector.examine(type).getAllProperties().get(name) != null;

     }

 

+    @Override

+    public Backup startBackup() throws RepositoryException {

+        synchronized (mBackupLock) {

+            int count = mBackupCount;

+            if (count == 0) {

+                try {

+                    enterBackupMode();

+                } catch (Exception e) {

+                    throw mExTransformer.toRepositoryException(e);

+                }

+            }

+            mBackupCount = count + 1;

+

+            return new Backup() {

+                private boolean mDone;

+

+                @Override

+                public void endBackup() throws RepositoryException {

+                    synchronized (mBackupLock) {

+                        if (mDone) {

+                            return;

+                        }

+                        mDone = true;

+

+                        int count = mBackupCount - 1;

+                        try {

+                            if (count == 0) {

+                                try {

+                                    exitBackupMode();

+                                } catch (Exception e) {

+                                    throw mExTransformer.toRepositoryException(e);

+                                }

+                            }

+                        } finally {

+                            mBackupCount = count;

+                        }

+                    }

+                }

+

+                @Override

+                public File[] getFiles() throws RepositoryException {

+                    synchronized (mBackupLock) {

+                        if (mDone) {

+                            throw new IllegalStateException("Backup has ended");

+                        }

+

+                        try {

+                            return backupFiles();

+                        } catch (Exception e) {

+                            throw mExTransformer.toRepositoryException(e);

+                        }

+                    }

+                }

+            };

+        }

+    }

+

     /**

      * Suspend the checkpointer until the suspension time has expired or until

      * manually resumed. If a checkpoint is in progress, this method will block

@@ -365,6 +426,28 @@ abstract class BDBRepository<Txn> extends AbstractRepository<Txn>
         return mIsMaster;

     }

 

+    String[] getAllDatabaseNames() throws RepositoryException {

+        Repository metaRepo = getRootRepository();

+

+        Cursor<StoredDatabaseInfo> cursor =

+            metaRepo.storageFor(StoredDatabaseInfo.class)

+            .query().orderBy("databaseName").fetch();

+

+        ArrayList<String> names = new ArrayList<String>();

+        // This one needs to manually added since it is the metadata db itself.

+        names.add(StoredDatabaseInfo.class.getName());

+

+        try {

+            while (cursor.hasNext()) {

+                names.add(cursor.next().getDatabaseName());

+            }

+        } finally {

+            cursor.close();

+        }

+

+        return names.toArray(new String[names.size()]);

+    }

+

     String getDatabaseFileName(final String dbName) {

         String singleFileName = mSingleFileName;

         if (singleFileName == null && mFileNameMap != null) {

@@ -527,6 +610,21 @@ abstract class BDBRepository<Txn> extends AbstractRepository<Txn>
     abstract <S extends Storable> BDBStorage<Txn, S> createBDBStorage(Class<S> type)

         throws Exception;

 

+    /**

+     * Called only the first time a backup is started.

+     */

+    abstract void enterBackupMode() throws Exception;

+

+    /**

+     * Called only after the last backup ends.

+     */

+    abstract void exitBackupMode() throws Exception;

+

+    /**

+     * Called only if in backup mode.

+     */

+    abstract File[] backupFiles() throws Exception;

+

     FetchException toFetchException(Throwable e) {

         return mExTransformer.toFetchException(e);

     }

diff --git a/src/main/java/com/amazon/carbonado/repo/sleepycat/CheckpointCapability.java b/src/main/java/com/amazon/carbonado/repo/sleepycat/CheckpointCapability.java
index dc4b3d7..c261d8a 100644
--- a/src/main/java/com/amazon/carbonado/repo/sleepycat/CheckpointCapability.java
+++ b/src/main/java/com/amazon/carbonado/repo/sleepycat/CheckpointCapability.java
@@ -22,9 +22,10 @@ import com.amazon.carbonado.PersistException;
 import com.amazon.carbonado.capability.Capability;

 

 /**

- * Capability to control BDB checkpointing. Useful when performing hot backups.

+ * Capability to control BDB checkpointing.

  *

  * @author Brian S O'Neill

+ * @see HotBackupCapability

  */

 public interface CheckpointCapability extends Capability {

     /**

@@ -33,9 +34,7 @@ public interface CheckpointCapability extends Capability {
      * until it is finished. If checkpointing is disabled, calling this method

      * has no effect.

      *

-     * <p>Calling this method repeatedly resets the suspension time. This

-     * technique should be used by hot backup processes to ensure that its

-     * failure does not leave the checkpointer permanently suspended. Each

+     * <p>Calling this method repeatedly resets the suspension time. Each

      * invocation of suspendCheckpointer is like a lease renewal or heartbeat.

      *

      * @param suspensionTime minimum length of suspension, in milliseconds,

diff --git a/src/main/java/com/amazon/carbonado/repo/sleepycat/HotBackupCapability.java b/src/main/java/com/amazon/carbonado/repo/sleepycat/HotBackupCapability.java
new file mode 100644
index 0000000..8bce86d
--- /dev/null
+++ b/src/main/java/com/amazon/carbonado/repo/sleepycat/HotBackupCapability.java
@@ -0,0 +1,56 @@
+/*

+ * Copyright 2009 Amazon Technologies, Inc. or its affiliates.

+ * Amazon, Amazon.com and Carbonado are trademarks or registered trademarks

+ * of Amazon Technologies, Inc. or its affiliates.  All rights reserved.

+ *

+ * Licensed 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 com.amazon.carbonado.repo.sleepycat;

+

+import java.io.File;

+

+import com.amazon.carbonado.RepositoryException;

+

+import com.amazon.carbonado.capability.Capability;

+

+/**

+ * Capability for performing a backup of an active BDB environment.

+ *

+ * @author Brian S O'Neill

+ * @since 1.2.1

+ */

+public interface HotBackupCapability extends Capability {

+    /**

+     * Starts the backup by disabling log file deletion. Be sure to call

+     * endBackup when done to resume log file cleanup. Concurrent backups is

+     * supported.

+     */

+    Backup startBackup() throws RepositoryException;

+

+    public static interface Backup {

+        /**

+         * End the backup and resume log file cleanup.

+         */

+        void endBackup() throws RepositoryException;

+

+        /**

+         * Returns all the files to be copied, in the exact order in which they

+         * must be copied.

+         *

+         * @return ordered array of absolute files

+         * @throws IllegalStateException if backup has ended

+         */

+        File[] getFiles() throws RepositoryException;

+    }

+}