HDDS-1141. Update DBCheckpointSnapshot to DBCheckpoint.

* HDDS-1141.Update DBCheckpointSnapshot to DBCheckpoint.

* fix test failures in TestOzoneConfigurationFields

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/DBCheckpointSnapshot.java → hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/DBCheckpoint.java

@@ -25,7 +25,7 @@ import java.nio.file.Path;
 /**
  * Generic DB Checkpoint interface.
  */
-public interface DBCheckpointSnapshot {
+public interface DBCheckpoint {
 
   /**
    * Get Snapshot location.

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/DBStore.java

@@ -143,6 +143,6 @@ public interface DBStore extends AutoCloseable {
    * @return An object that encapsulates the checkpoint information along with
    * location.
    */
-  DBCheckpointSnapshot getCheckpointSnapshot(boolean flush) throws IOException;
+  DBCheckpoint getCheckpoint(boolean flush) throws IOException;
 
 }

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/RDBCheckpointManager.java

@@ -68,8 +68,7 @@ public class RDBCheckpointManager {
    * @param parentDir The directory where the checkpoint needs to be created.
    * @return RocksDB specific Checkpoint information object.
    */
-  public RocksDBCheckpointSnapshot createCheckpointSnapshot(String parentDir)
-      throws IOException {
+  public RocksDBCheckpoint createCheckpoint(String parentDir) {
     try {
       long currentTime = System.currentTimeMillis();
 
@@ -82,7 +81,7 @@ public class RDBCheckpointManager {
       Path checkpointPath = Paths.get(parentDir, checkpointDir);
       checkpoint.createCheckpoint(checkpointPath.toString());
 
-      return new RocksDBCheckpointSnapshot(
+      return new RocksDBCheckpoint(
           checkpointPath,
           currentTime,
           db.getLatestSequenceNumber()); //Best guesstimate here. Not accurate.
@@ -93,13 +92,13 @@ public class RDBCheckpointManager {
     return null;
   }
 
-  static class RocksDBCheckpointSnapshot implements DBCheckpointSnapshot {
+  static class RocksDBCheckpoint implements DBCheckpoint {
 
     private Path checkpointLocation;
     private long checkpointTimestamp;
     private long latestSequenceNumber;
 
-    RocksDBCheckpointSnapshot(Path checkpointLocation,
+    RocksDBCheckpoint(Path checkpointLocation,
                               long snapshotTimestamp,
                               long latestSequenceNumber) {
       this.checkpointLocation = checkpointLocation;

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/db/RDBStore.java

@@ -268,18 +268,14 @@ public class RDBStore implements DBStore {
   }
 
   @Override
-  public DBCheckpointSnapshot getCheckpointSnapshot(boolean flush)
-      throws IOException {
-    if (flush) {
-      final FlushOptions flushOptions =
-          new FlushOptions().setWaitForFlush(true);
-      try {
-        db.flush(flushOptions);
-      } catch (RocksDBException e) {
-        LOG.error("Unable to Flush RocksDB data before creating snapshot", e);
-      }
+  public DBCheckpoint getCheckpoint(boolean flush) {
+    final FlushOptions flushOptions = new FlushOptions().setWaitForFlush(flush);
+    try {
+      db.flush(flushOptions);
+    } catch (RocksDBException e) {
+      LOG.error("Unable to Flush RocksDB data before creating snapshot", e);
     }
-    return checkPointManager.createCheckpointSnapshot(checkpointsParentDir);
+    return checkPointManager.createCheckpoint(checkpointsParentDir);
   }
 
 }

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -1882,7 +1882,7 @@
     </description>
   </property>
   <property>
-    <name>ozone.manager.db.snapshot.transfer.bandwidthPerSec</name>
+    <name>ozone.manager.db.checkpoint.transfer.bandwidthPerSec</name>
     <value>0</value>
     <tag>OZONE</tag>
     <description>

hadoop-hdds/common/src/test/java/org/apache/hadoop/utils/db/TestRDBStore.java

@@ -254,19 +254,19 @@ public class TestRDBStore {
       Assert.assertNotNull("DB Store cannot be null", newStore);
 
       insertRandomData(newStore, 1);
-      DBCheckpointSnapshot checkpointSnapshot =
-          newStore.getCheckpointSnapshot(true);
-      Assert.assertNotNull(checkpointSnapshot);
+      DBCheckpoint checkpoint =
+          newStore.getCheckpoint(true);
+      Assert.assertNotNull(checkpoint);
 
       RDBStore restoredStoreFromCheckPoint =
-          new RDBStore(checkpointSnapshot.getCheckpointLocation().toFile(),
+          new RDBStore(checkpoint.getCheckpointLocation().toFile(),
               options, configSet);
 
       // Let us make sure that our estimate is not off by 10%
       Assert.assertTrue(
           restoredStoreFromCheckPoint.getEstimatedKeyCount() > 90
           || restoredStoreFromCheckPoint.getEstimatedKeyCount() < 110);
-      checkpointSnapshot.cleanupCheckpoint();
+      checkpoint.cleanupCheckpoint();
     }
 
   }
@@ -278,15 +278,15 @@ public class TestRDBStore {
       Assert.assertNotNull("DB Store cannot be null", newStore);
 
       insertRandomData(newStore, 1);
-      DBCheckpointSnapshot checkpointSnapshot =
-          newStore.getCheckpointSnapshot(true);
-      Assert.assertNotNull(checkpointSnapshot);
+      DBCheckpoint checkpoint =
+          newStore.getCheckpoint(true);
+      Assert.assertNotNull(checkpoint);
 
       Assert.assertTrue(Files.exists(
-          checkpointSnapshot.getCheckpointLocation()));
-      checkpointSnapshot.cleanupCheckpoint();
+          checkpoint.getCheckpointLocation()));
+      checkpoint.cleanupCheckpoint();
       Assert.assertFalse(Files.exists(
-          checkpointSnapshot.getCheckpointLocation()));
+          checkpoint.getCheckpointLocation()));
     }
   }
 }

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/OMConfigKeys.java

@@ -205,9 +205,9 @@ public final class OMConfigKeys {
   public static final long    DELEGATION_TOKEN_MAX_LIFETIME_DEFAULT =
       7*24*60*60*1000; // 7 days
 
-  public static final String OZONE_DB_SNAPSHOT_TRANSFER_RATE_KEY =
-      "ozone.manager.db.snapshot.transfer.bandwidthPerSec";
-  public static final long OZONE_DB_SNAPSHOT_TRANSFER_RATE_DEFAULT =
+  public static final String OZONE_DB_CHECKPOINT_TRANSFER_RATE_KEY =
+      "ozone.manager.db.checkpoint.transfer.bandwidthPerSec";
+  public static final long OZONE_DB_CHECKPOINT_TRANSFER_RATE_DEFAULT =
       0;  //no throttling
 
 }

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OMDbSnapshotServlet.java → hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OMDBCheckpointServlet.java

@@ -39,17 +39,17 @@ import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ozone.OmUtils;
 import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.utils.db.DBStore;
-import org.apache.hadoop.utils.db.DBCheckpointSnapshot;
+import org.apache.hadoop.utils.db.DBCheckpoint;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * Provides the current checkpoint Snapshot of the OM DB. (tar.gz)
  */
-public class OMDbSnapshotServlet extends HttpServlet {
+public class OMDBCheckpointServlet extends HttpServlet {
 
   private static final Logger LOG =
-      LoggerFactory.getLogger(OMDbSnapshotServlet.class);
+      LoggerFactory.getLogger(OMDBCheckpointServlet.class);
   private static final long serialVersionUID = 1L;
 
   private transient DBStore omDbStore;
@@ -62,15 +62,15 @@ public class OMDbSnapshotServlet extends HttpServlet {
         .getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE);
 
     if (om == null) {
-      LOG.error("Unable to initialize OMDbSnapshotServlet. OM is null");
+      LOG.error("Unable to initialize OMDBCheckpointServlet. OM is null");
       return;
     }
 
     omDbStore = om.getMetadataManager().getStore();
     OzoneConfiguration configuration = om.getConfiguration();
     long transferBandwidth = configuration.getLongBytes(
-        OMConfigKeys.OZONE_DB_SNAPSHOT_TRANSFER_RATE_KEY,
-        OMConfigKeys.OZONE_DB_SNAPSHOT_TRANSFER_RATE_DEFAULT);
+        OMConfigKeys.OZONE_DB_CHECKPOINT_TRANSFER_RATE_KEY,
+        OMConfigKeys.OZONE_DB_CHECKPOINT_TRANSFER_RATE_DEFAULT);
 
     if (transferBandwidth > 0) {
       throttler = new DataTransferThrottler(transferBandwidth);
@@ -105,7 +105,7 @@ public class OMDbSnapshotServlet extends HttpServlet {
         flush = Boolean.valueOf(flushParam);
       }
 
-      DBCheckpointSnapshot checkpoint = omDbStore.getCheckpointSnapshot(flush);
+      DBCheckpoint checkpoint = omDbStore.getCheckpoint(flush);
       if (checkpoint == null) {
         LOG.error("Unable to process metadata snapshot request. " +
             "Checkpoint request returned null.");

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManagerHttpServer.java

@@ -32,7 +32,7 @@ public class OzoneManagerHttpServer extends BaseHttpServer {
       throws IOException {
     super(conf, "ozoneManager");
     addServlet("serviceList", "/serviceList", ServiceListJSONServlet.class);
-    addServlet("dbSnapshot", "/dbSnapshot", OMDbSnapshotServlet.class);
+    addServlet("dbCheckpoint", "/dbCheckpoint", OMDBCheckpointServlet.class);
     getWebAppContext().setAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE, om);
   }