* Tests save namespace.
*/
@Test
public void testSaveNamespace() throws IOException {
MiniDFSCluster cluster = null;
DistributedFileSystem fs = null;
FileContext fc;
try {
Configuration conf = new HdfsConfiguration();
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDatanodes).format(true).build();
cluster.waitActive();
fs = (cluster.getFileSystem());
fc = FileContext.getFileContext(cluster.getURI(0));
// Saving image without safe mode should fail
DFSAdmin admin = new DFSAdmin(conf);
String[] args = new String[]{"-saveNamespace"};
try {
admin.run(args);
} catch(IOException eIO) {
assertTrue(eIO.getLocalizedMessage().contains("Safe mode should be turned ON"));
} catch(Exception e) {
throw new IOException(e);
}
// create new file
Path file = new Path("namespace.dat");
writeFile(fs, file, replication);
checkFile(fs, file, replication);
// create new link
Path symlink = new Path("file.link");
fc.createSymlink(file, symlink, false);
assertTrue(fc.getFileLinkStatus(symlink).isSymlink());
// verify that the edits file is NOT empty
Collection<URI> editsDirs = cluster.getNameEditsDirs(0);
for(URI uri : editsDirs) {
File ed = new File(uri.getPath());
assertTrue(new File(ed, "current/"
+ NNStorage.getInProgressEditsFileName(1))
.length() > Integer.SIZE/Byte.SIZE);
}
// Saving image in safe mode should succeed
fs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
try {
admin.run(args);
} catch(Exception e) {
throw new IOException(e);
}
// TODO: Fix the test to not require a hard-coded transaction count.
final int EXPECTED_TXNS_FIRST_SEG = 13;
// the following steps should have happened:
// edits_inprogress_1 -> edits_1-12 (finalized)
// fsimage_12 created
// edits_inprogress_13 created
//
for(URI uri : editsDirs) {
File ed = new File(uri.getPath());
File curDir = new File(ed, "current");
LOG.info("Files in " + curDir + ":\n " +
Joiner.on("\n ").join(curDir.list()));
// Verify that the first edits file got finalized
File originalEdits = new File(curDir,
NNStorage.getInProgressEditsFileName(1));
assertFalse(originalEdits.exists());
File finalizedEdits = new File(curDir,
NNStorage.getFinalizedEditsFileName(1, EXPECTED_TXNS_FIRST_SEG));
GenericTestUtils.assertExists(finalizedEdits);
assertTrue(finalizedEdits.length() > Integer.SIZE/Byte.SIZE);
GenericTestUtils.assertExists(new File(ed, "current/"
+ NNStorage.getInProgressEditsFileName(
EXPECTED_TXNS_FIRST_SEG + 1)));
}
Collection<URI> imageDirs = cluster.getNameDirs(0);
for (URI uri : imageDirs) {
File imageDir = new File(uri.getPath());
File savedImage = new File(imageDir, "current/"
+ NNStorage.getImageFileName(
EXPECTED_TXNS_FIRST_SEG));
assertTrue("Should have saved image at " + savedImage,
savedImage.exists());
}
// restart cluster and verify file exists
cluster.shutdown();
cluster = null;
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDatanodes).format(false).build();
cluster.waitActive();
fs = (cluster.getFileSystem());
checkFile(fs, file, replication);
fc = FileContext.getFileContext(cluster.getURI(0));
assertTrue(fc.getFileLinkStatus(symlink).isSymlink());
} finally {
if(fs != null) fs.close();
cleanup(cluster);
cluster = null;
}
}