secondary = new SecondaryNameNode(conf);
SnapshotManager nnSnapshotManager = cluster.getNamesystem().getSnapshotManager();
SnapshotManager secondarySnapshotManager = secondary.getFSNamesystem().getSnapshotManager();
FileSystem fs = cluster.getFileSystem();
HdfsAdmin admin = new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
assertEquals(0, nnSnapshotManager.getNumSnapshots());
assertEquals(0, nnSnapshotManager.getNumSnapshottableDirs());
assertEquals(0, secondarySnapshotManager.getNumSnapshots());
assertEquals(0, secondarySnapshotManager.getNumSnapshottableDirs());
// 1. Create a snapshottable directory foo on the NN.
fs.mkdirs(TEST_PATH);
admin.allowSnapshot(TEST_PATH);
assertEquals(0, nnSnapshotManager.getNumSnapshots());
assertEquals(1, nnSnapshotManager.getNumSnapshottableDirs());
// 2. Create a snapshot of the dir foo. This will be referenced both in
// the SnapshotManager as well as in the file system tree. The snapshot
// count will go up to 1.
Path snapshotPath = fs.createSnapshot(TEST_PATH);
assertEquals(1, nnSnapshotManager.getNumSnapshots());
assertEquals(1, nnSnapshotManager.getNumSnapshottableDirs());
// 3. Start up a 2NN and have it do a checkpoint. It will have foo and its
// snapshot in its list of snapshottable dirs referenced from the
// SnapshotManager, as well as in the file system tree.
secondary.doCheckpoint();
assertEquals(1, secondarySnapshotManager.getNumSnapshots());
assertEquals(1, secondarySnapshotManager.getNumSnapshottableDirs());
// 4. Disallow snapshots on and delete foo on the NN. The snapshot count
// will go down to 0 and the snapshottable dir will be removed from the fs
// tree.
fs.deleteSnapshot(TEST_PATH, snapshotPath.getName());
admin.disallowSnapshot(TEST_PATH);
assertEquals(0, nnSnapshotManager.getNumSnapshots());
assertEquals(0, nnSnapshotManager.getNumSnapshottableDirs());
// 5. Have the NN do a saveNamespace, writing out a new fsimage with
// snapshot count 0.