HDFS-15498. Show snapshots deletion status in snapList cmd. (#2181)

Author: bshashikant

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotStatus.java

@@ -40,6 +40,11 @@ public class SnapshotStatus {
    */
   private final int snapshotID;
 
+  /**
+   * Whether the snapshot is deleted or not.
+   */
+  private final boolean isDeleted;
+
   /**
    * Full path of the parent.
    */
@@ -50,7 +55,7 @@ public SnapshotStatus(long modificationTime, long accessTime,
                         EnumSet<HdfsFileStatus.Flags> flags,
                         String owner, String group, byte[] localName,
                         long inodeId, int childrenNum, int snapshotID,
-                        byte[] parentFullPath) {
+                        boolean isDeleted, byte[] parentFullPath) {
     this.dirStatus = new HdfsFileStatus.Builder()
         .isdir(true)
         .mtime(modificationTime)
@@ -64,13 +69,7 @@ public SnapshotStatus(long modificationTime, long accessTime,
         .children(childrenNum)
         .build();
     this.snapshotID = snapshotID;
-    this.parentFullPath = parentFullPath;
-  }
-
-  public SnapshotStatus(HdfsFileStatus dirStatus,
-                        int snapshotNumber, byte[] parentFullPath) {
-    this.dirStatus = dirStatus;
-    this.snapshotID = snapshotNumber;
+    this.isDeleted = isDeleted;
     this.parentFullPath = parentFullPath;
   }
 
@@ -89,6 +88,13 @@ public int getSnapshotID() {
     return snapshotID;
   }
 
+  /**
+   * @return whether snapshot is deleted
+   */
+  public boolean isDeleted() {
+    return isDeleted;
+  }
+
   /**
    * @return The basic information of the directory
    */
@@ -143,6 +149,7 @@ public static void print(SnapshotStatus[] stats,
         + "%" + maxLen + "s "
         + "%s " // mod time
         + "%" + maxSnapshotID + "s "
+        + "%s " // deletion status
         + "%s"; // path
     SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
@@ -155,6 +162,7 @@ public static void print(SnapshotStatus[] stats,
           String.valueOf(status.dirStatus.getLen()),
           dateFormat.format(new Date(status.dirStatus.getModificationTime())),
           status.snapshotID,
+          status.isDeleted ? "DELETED" : "ACTIVE",
           getSnapshotPath(DFSUtilClient.bytes2String(status.parentFullPath),
               status.dirStatus.getLocalName())
       );
@@ -166,22 +174,29 @@ private static int maxLength(int n, Object value) {
     return Math.max(n, String.valueOf(value).length());
   }
 
+  /**
+   * To be used to for collection of snapshot jmx.
+   */
   public static class Bean {
     private final String path;
     private final int snapshotID;
     private final long modificationTime;
     private final short permission;
     private final String owner;
     private final String group;
+    private final boolean isDeleted;
+
 
     public Bean(String path, int snapshotID, long
-        modificationTime, short permission, String owner, String group) {
+        modificationTime, short permission, String owner, String group,
+                boolean isDeleted) {
       this.path = path;
       this.snapshotID = snapshotID;
       this.modificationTime = modificationTime;
       this.permission = permission;
       this.owner = owner;
       this.group = group;
+      this.isDeleted = isDeleted;
     }
 
     public String getPath() {
@@ -207,6 +222,10 @@ public String getOwner() {
     public String getGroup() {
       return group;
     }
+
+    public boolean isDeleted() {
+      return isDeleted;
+    }
   }
 
   static String getSnapshotPath(String snapshottableDir,

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java

@@ -1711,6 +1711,7 @@ public static SnapshotStatus convert(
         status.getFileId(),
         status.getChildrenNum(),
         sdirStatusProto.getSnapshotID(),
+        sdirStatusProto.getIsDeleted(),
         sdirStatusProto.getParentFullpath().toByteArray());
   }
 
@@ -2425,6 +2426,7 @@ public static HdfsProtos.SnapshotStatusProto convert(SnapshotStatus status) {
             .newBuilder()
             .setSnapshotID(status.getSnapshotID())
             .setParentFullpath(parentFullPathBytes)
+            .setIsDeleted(status.isDeleted())
             .setDirStatus(fs);
     return builder.build();
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/proto/hdfs.proto

@@ -574,6 +574,7 @@ message SnapshotStatusProto {
   // Fields specific for snapshot directory
   required uint32 snapshotID = 2;
   required bytes parent_fullpath = 3;
+  required bool isDeleted = 4;
 }
 
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/snapshot/SnapshotManager.java

@@ -599,7 +599,8 @@ public SnapshotStatus[] getSnapshotListing(INodesInPath iip)
           // It is expensive to build the snapshot tree for the directory
           // and determine the child count.
           dir.getChildrenNum(Snapshot.CURRENT_STATE_ID),
-          s.getId(), DFSUtil.string2Bytes(dir.getParent().getFullPathName()));
+          s.getId(), s.getRoot().isMarkedAsDeleted(),
+          DFSUtil.string2Bytes(dir.getParent().getFullPathName()));
 
     }
     return statuses;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestListSnapshot.java

@@ -30,7 +30,10 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import static org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotManager.
+    DFS_NAMENODE_SNAPSHOT_DELETION_ORDERED;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
@@ -51,6 +54,7 @@ public class TestListSnapshot {
   @Before
   public void setUp() throws Exception {
     conf = new Configuration();
+    conf.setBoolean(DFS_NAMENODE_SNAPSHOT_DELETION_ORDERED, true);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(REPLICATION)
         .build();
     cluster.waitActive();
@@ -128,7 +132,15 @@ public void testListSnapshot() throws Exception {
         snapshotStatuses[2].getFullPath());
     hdfs.deleteSnapshot(dir1, "s2");
     snapshotStatuses = hdfs.getSnapshotListing(dir1);
-    // There are now 2 snapshots for dir1
+    // There are now 2 active snapshots for dir1 and one is marked deleted
+    assertEquals(3, snapshotStatuses.length);
+    assertTrue(snapshotStatuses[2].isDeleted());
+    assertFalse(snapshotStatuses[1].isDeleted());
+    assertFalse(snapshotStatuses[0].isDeleted());
+    // delete the 1st snapshot
+    hdfs.deleteSnapshot(dir1, "s0");
+    snapshotStatuses = hdfs.getSnapshotListing(dir1);
+    // There are now 2 snapshots now as the 1st one is deleted in order
     assertEquals(2, snapshotStatuses.length);
   }
 }