public virtual void TestSnapshotOnRoot()
{
Path root = new Path("/");
hdfs.AllowSnapshot(root);
hdfs.CreateSnapshot(root, "s1");
cluster.Shutdown();
cluster = new MiniDFSCluster.Builder(conf).Format(false).NumDataNodes(Replication
).Build();
cluster.WaitActive();
fsn = cluster.GetNamesystem();
hdfs = cluster.GetFileSystem();
// save namespace and restart cluster
hdfs.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeEnter);
hdfs.SaveNamespace();
hdfs.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeLeave);
cluster.Shutdown();
cluster = new MiniDFSCluster.Builder(conf).Format(false).NumDataNodes(Replication
).Build();
cluster.WaitActive();
fsn = cluster.GetNamesystem();
hdfs = cluster.GetFileSystem();
INodeDirectory rootNode = fsn.dir.GetINode4Write(root.ToString()).AsDirectory();
NUnit.Framework.Assert.IsTrue("The children list of root should be empty", rootNode
.GetChildrenList(Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot.CurrentStateId
).IsEmpty());
// one snapshot on root: s1
IList <DirectoryWithSnapshotFeature.DirectoryDiff> diffList = rootNode.GetDiffs().
AsList();
NUnit.Framework.Assert.AreEqual(1, diffList.Count);
Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot s1 = rootNode.GetSnapshot
(DFSUtil.String2Bytes("s1"));
NUnit.Framework.Assert.AreEqual(s1.GetId(), diffList[0].GetSnapshotId());
// check SnapshotManager's snapshottable directory list
NUnit.Framework.Assert.AreEqual(1, fsn.GetSnapshotManager().GetNumSnapshottableDirs
());
SnapshottableDirectoryStatus[] sdirs = fsn.GetSnapshotManager().GetSnapshottableDirListing
(null);
NUnit.Framework.Assert.AreEqual(root, sdirs[0].GetFullPath());
// save namespace and restart cluster
hdfs.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeEnter);
hdfs.SaveNamespace();
hdfs.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeLeave);
cluster.Shutdown();
cluster = new MiniDFSCluster.Builder(conf).Format(false).NumDataNodes(Replication
).Build();
cluster.WaitActive();
fsn = cluster.GetNamesystem();
hdfs = cluster.GetFileSystem();
}