001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.util;
019
020import static org.junit.jupiter.api.Assertions.assertEquals;
021import static org.junit.jupiter.api.Assertions.assertFalse;
022import static org.junit.jupiter.api.Assertions.assertNotEquals;
023import static org.junit.jupiter.api.Assertions.assertNotNull;
024import static org.junit.jupiter.api.Assertions.assertNull;
025import static org.junit.jupiter.api.Assertions.assertTrue;
026import static org.junit.jupiter.api.Assertions.fail;
027
028import java.io.IOException;
029import java.util.Arrays;
030import java.util.Comparator;
031import java.util.Map;
032import org.apache.hadoop.fs.FSDataOutputStream;
033import org.apache.hadoop.fs.FileStatus;
034import org.apache.hadoop.fs.FileSystem;
035import org.apache.hadoop.fs.Path;
036import org.apache.hadoop.hbase.HBaseCommonTestingUtil;
037import org.apache.hadoop.hbase.HConstants;
038import org.apache.hadoop.hbase.TableDescriptors;
039import org.apache.hadoop.hbase.TableName;
040import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
041import org.apache.hadoop.hbase.client.TableDescriptor;
042import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
043import org.apache.hadoop.hbase.testclassification.MediumTests;
044import org.apache.hadoop.hbase.testclassification.MiscTests;
045import org.junit.jupiter.api.AfterAll;
046import org.junit.jupiter.api.BeforeEach;
047import org.junit.jupiter.api.Tag;
048import org.junit.jupiter.api.Test;
049import org.junit.jupiter.api.TestInfo;
050import org.slf4j.Logger;
051import org.slf4j.LoggerFactory;
052
053/**
054 * Tests for {@link FSTableDescriptors}.
055 */
056// Do not support to be executed in he same JVM as other tests
057@Tag(MiscTests.TAG)
058@Tag(MediumTests.TAG)
059public class TestFSTableDescriptors {
060
061  private static final HBaseCommonTestingUtil UTIL = new HBaseCommonTestingUtil();
062  private static final Logger LOG = LoggerFactory.getLogger(TestFSTableDescriptors.class);
063
064  private Path testDir;
065
066  @BeforeEach
067  public void setUp(TestInfo testInfo) {
068    testDir = UTIL.getDataTestDir(testInfo.getTestMethod().get().getName());
069  }
070
071  @AfterAll
072  public static void tearDownAfterClass() {
073    UTIL.cleanupTestDir();
074  }
075
076  @Test
077  public void testRegexAgainstOldStyleTableInfo() {
078    Path p = new Path(testDir, FSTableDescriptors.TABLEINFO_FILE_PREFIX);
079    int i = FSTableDescriptors.getTableInfoSequenceIdAndFileLength(p).sequenceId;
080    assertEquals(0, i);
081    // Assert it won't eat garbage -- that it fails
082    Path p2 = new Path(testDir, "abc");
083    org.junit.jupiter.api.Assertions.assertThrows(IllegalArgumentException.class,
084      () -> FSTableDescriptors.getTableInfoSequenceIdAndFileLength(p2));
085  }
086
087  @Test
088  public void testCreateAndUpdate(TestInfo testInfo) throws IOException {
089    TableDescriptor htd = TableDescriptorBuilder
090      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
091    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
092    FSTableDescriptors fstd = new FSTableDescriptors(fs, testDir);
093    assertTrue(fstd.createTableDescriptor(htd));
094    assertFalse(fstd.createTableDescriptor(htd));
095    Path tableInfoDir = new Path(CommonFSUtils.getTableDir(testDir, htd.getTableName()),
096      FSTableDescriptors.TABLEINFO_DIR);
097    FileStatus[] statuses = fs.listStatus(tableInfoDir);
098    assertEquals(1, statuses.length, "statuses.length=" + statuses.length);
099    for (int i = 0; i < 10; i++) {
100      fstd.update(htd);
101    }
102    statuses = fs.listStatus(tableInfoDir);
103    assertEquals(1, statuses.length);
104  }
105
106  @Test
107  public void testSequenceIdAdvancesOnTableInfo(TestInfo testInfo) throws IOException {
108    TableDescriptor htd = TableDescriptorBuilder
109      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
110    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
111    FSTableDescriptors fstd = new FSTableDescriptors(fs, testDir);
112    Path previousPath = null;
113    int previousSeqId = -1;
114    for (int i = 0; i < 10; i++) {
115      Path path = fstd.updateTableDescriptor(htd);
116      int seqId = FSTableDescriptors.getTableInfoSequenceIdAndFileLength(path).sequenceId;
117      if (previousPath != null) {
118        // Assert we cleaned up the old file.
119        assertTrue(!fs.exists(previousPath));
120        assertEquals(previousSeqId + 1, seqId);
121      }
122      previousPath = path;
123      previousSeqId = seqId;
124    }
125  }
126
127  @Test
128  public void testFormatTableInfoSequenceId() {
129    Path p0 = assertWriteAndReadSequenceId(0);
130    // Assert p0 has format we expect.
131    StringBuilder sb = new StringBuilder();
132    for (int i = 0; i < FSTableDescriptors.WIDTH_OF_SEQUENCE_ID; i++) {
133      sb.append("0");
134    }
135    assertEquals(FSTableDescriptors.TABLEINFO_FILE_PREFIX + "." + sb.toString() + ".0",
136      p0.getName());
137    // Check a few more.
138    Path p2 = assertWriteAndReadSequenceId(2);
139    Path p10000 = assertWriteAndReadSequenceId(10000);
140    // Get a .tablinfo that has no sequenceid suffix.
141    Path p = new Path(p0.getParent(), FSTableDescriptors.TABLEINFO_FILE_PREFIX);
142    FileStatus fs = new FileStatus(0, false, 0, 0, 0, p);
143    FileStatus fs0 = new FileStatus(0, false, 0, 0, 0, p0);
144    FileStatus fs2 = new FileStatus(0, false, 0, 0, 0, p2);
145    FileStatus fs10000 = new FileStatus(0, false, 0, 0, 0, p10000);
146    Comparator<FileStatus> comparator = FSTableDescriptors.TABLEINFO_FILESTATUS_COMPARATOR;
147    assertTrue(comparator.compare(fs, fs0) > 0);
148    assertTrue(comparator.compare(fs0, fs2) > 0);
149    assertTrue(comparator.compare(fs2, fs10000) > 0);
150  }
151
152  private Path assertWriteAndReadSequenceId(final int i) {
153    Path p =
154      new Path(testDir, FSTableDescriptors.getTableInfoFileName(i, HConstants.EMPTY_BYTE_ARRAY));
155    int ii = FSTableDescriptors.getTableInfoSequenceIdAndFileLength(p).sequenceId;
156    assertEquals(i, ii);
157    return p;
158  }
159
160  @Test
161  public void testRemoves(TestInfo testInfo) throws IOException {
162    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
163    // Cleanup old tests if any detrius laying around.
164    TableDescriptors htds = new FSTableDescriptors(fs, testDir);
165    TableDescriptor htd = TableDescriptorBuilder
166      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
167    htds.update(htd);
168    assertNotNull(htds.remove(htd.getTableName()));
169    assertNull(htds.remove(htd.getTableName()));
170  }
171
172  @Test
173  public void testReadingHTDFromFS(TestInfo testInfo) throws IOException {
174    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
175    TableDescriptor htd = TableDescriptorBuilder
176      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
177    FSTableDescriptors fstd = new FSTableDescriptors(fs, testDir);
178    fstd.createTableDescriptor(htd);
179    TableDescriptor td2 =
180      FSTableDescriptors.getTableDescriptorFromFs(fs, testDir, htd.getTableName());
181    assertTrue(htd.equals(td2));
182  }
183
184  @Test
185  public void testTableDescriptors(TestInfo testInfo) throws IOException, InterruptedException {
186    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
187    // Cleanup old tests if any debris laying around.
188    FSTableDescriptors htds = new FSTableDescriptors(fs, testDir) {
189      @Override
190      public TableDescriptor get(TableName tablename) {
191        LOG.info(tablename + ", cachehits=" + this.cachehits);
192        return super.get(tablename);
193      }
194    };
195    final int count = 10;
196    // Write out table infos.
197    for (int i = 0; i < count; i++) {
198      htds.createTableDescriptor(TableDescriptorBuilder
199        .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)).build());
200    }
201
202    for (int i = 0; i < count; i++) {
203      assertTrue(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)) != null);
204    }
205    for (int i = 0; i < count; i++) {
206      assertTrue(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)) != null);
207    }
208    // Update the table infos
209    for (int i = 0; i < count; i++) {
210      TableDescriptorBuilder builder = TableDescriptorBuilder
211        .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName() + i));
212      builder.setColumnFamily(ColumnFamilyDescriptorBuilder.of("" + i));
213      htds.update(builder.build());
214    }
215    // Wait a while so mod time we write is for sure different.
216    Thread.sleep(100);
217    for (int i = 0; i < count; i++) {
218      assertTrue(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)) != null);
219    }
220    for (int i = 0; i < count; i++) {
221      assertTrue(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)) != null);
222    }
223    assertEquals(count * 4, htds.invocations);
224    assertTrue(htds.cachehits >= (count * 2),
225      "expected=" + (count * 2) + ", actual=" + htds.cachehits);
226  }
227
228  @Test
229  public void testTableDescriptorsNoCache(TestInfo testInfo)
230    throws IOException, InterruptedException {
231    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
232    // Cleanup old tests if any debris laying around.
233    FSTableDescriptors htds = new FSTableDescriptorsTest(fs, testDir, false);
234    final int count = 10;
235    // Write out table infos.
236    for (int i = 0; i < count; i++) {
237      htds.createTableDescriptor(TableDescriptorBuilder
238        .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)).build());
239    }
240
241    for (int i = 0; i < 2 * count; i++) {
242      assertNotNull(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i % 2)),
243        "Expected HTD, got null instead");
244    }
245    // Update the table infos
246    for (int i = 0; i < count; i++) {
247      TableDescriptorBuilder builder = TableDescriptorBuilder
248        .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName() + i));
249      builder.setColumnFamily(ColumnFamilyDescriptorBuilder.of("" + i));
250      htds.update(builder.build());
251    }
252    for (int i = 0; i < count; i++) {
253      assertNotNull(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)),
254        "Expected HTD, got null instead");
255      assertTrue(htds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i))
256        .hasColumnFamily(Bytes.toBytes("" + i)), "Column Family " + i + " missing");
257    }
258    assertEquals(count * 4, htds.invocations);
259    assertEquals(0, htds.cachehits, "expected=0, actual=" + htds.cachehits);
260  }
261
262  @Test
263  public void testGetAll() throws IOException, InterruptedException {
264    final String name = "testGetAll";
265    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
266    // Cleanup old tests if any debris laying around.
267    FSTableDescriptors htds = new FSTableDescriptorsTest(fs, testDir);
268    final int count = 4;
269    // Write out table infos.
270    for (int i = 0; i < count; i++) {
271      htds.createTableDescriptor(
272        TableDescriptorBuilder.newBuilder(TableName.valueOf(name + i)).build());
273    }
274    // add hbase:meta
275    htds
276      .createTableDescriptor(TableDescriptorBuilder.newBuilder(TableName.META_TABLE_NAME).build());
277    assertEquals(count + 1, htds.getAll().size(),
278      "getAll() didn't return all TableDescriptors, expected: " + (count + 1) + " got: "
279        + htds.getAll().size());
280  }
281
282  @Test
283  public void testParallelGetAll() throws IOException, InterruptedException {
284    final String name = "testParallelGetAll";
285    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
286    // Enable parallel load table descriptor.
287    FSTableDescriptors htds = new FSTableDescriptorsTest(fs, testDir, true, 20);
288    final int count = 100;
289    // Write out table infos.
290    for (int i = 0; i < count; i++) {
291      htds.createTableDescriptor(
292        TableDescriptorBuilder.newBuilder(TableName.valueOf(name + i)).build());
293    }
294    // add hbase:meta
295    htds
296      .createTableDescriptor(TableDescriptorBuilder.newBuilder(TableName.META_TABLE_NAME).build());
297
298    int getTableDescriptorSize = htds.getAll().size();
299    assertEquals(count + 1, getTableDescriptorSize,
300      "getAll() didn't return all TableDescriptors, expected: " + (count + 1) + " got: "
301        + getTableDescriptorSize);
302
303    // get again to check whether the cache works well
304    getTableDescriptorSize = htds.getAll().size();
305    assertEquals(count + 1, getTableDescriptorSize,
306      "getAll() didn't return all TableDescriptors with cache, expected: " + (count + 1) + " got: "
307        + getTableDescriptorSize);
308  }
309
310  @Test
311  public void testGetAllOrdering() throws Exception {
312    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
313    FSTableDescriptors tds = new FSTableDescriptorsTest(fs, testDir);
314
315    String[] tableNames = new String[] { "foo", "bar", "foo:bar", "bar:foo" };
316    for (String tableName : tableNames) {
317      tds.createTableDescriptor(
318        TableDescriptorBuilder.newBuilder(TableName.valueOf(tableName)).build());
319    }
320
321    Map<String, TableDescriptor> tables = tds.getAll();
322    // Remove hbase:meta from list. It shows up now since we made it dynamic. The schema
323    // is written into the fs by the FSTableDescriptors constructor now where before it
324    // didn't.
325    tables.remove(TableName.META_TABLE_NAME.getNameAsString());
326    assertEquals(4, tables.size());
327
328    String[] tableNamesOrdered =
329      new String[] { "bar:foo", "default:bar", "default:foo", "foo:bar" };
330    int i = 0;
331    for (Map.Entry<String, TableDescriptor> entry : tables.entrySet()) {
332      assertEquals(tableNamesOrdered[i], entry.getKey());
333      assertEquals(tableNamesOrdered[i],
334        entry.getValue().getTableName().getNameWithNamespaceInclAsString());
335      i++;
336    }
337  }
338
339  @Test
340  public void testCacheConsistency(TestInfo testInfo) throws IOException, InterruptedException {
341    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
342    // Cleanup old tests if any debris laying around.
343    FSTableDescriptors chtds = new FSTableDescriptorsTest(fs, testDir);
344    FSTableDescriptors nonchtds = new FSTableDescriptorsTest(fs, testDir, false);
345
346    final int count = 10;
347    // Write out table infos via non-cached FSTableDescriptors
348    for (int i = 0; i < count; i++) {
349      nonchtds.createTableDescriptor(TableDescriptorBuilder
350        .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)).build());
351    }
352
353    // Calls to getAll() won't increase the cache counter, do per table.
354    for (int i = 0; i < count; i++) {
355      assertTrue(
356        chtds.get(TableName.valueOf(testInfo.getTestMethod().get().getName() + i)) != null);
357    }
358
359    assertTrue(nonchtds.getAll().size() == chtds.getAll().size());
360
361    // add a new entry for random table name.
362    TableName random = TableName.valueOf("random");
363    TableDescriptor htd = TableDescriptorBuilder.newBuilder(random).build();
364    nonchtds.createTableDescriptor(htd);
365
366    // random will only increase the cachehit by 1
367    assertEquals(nonchtds.getAll().size(), chtds.getAll().size() + 1);
368
369    for (Map.Entry<String, TableDescriptor> entry : chtds.getAll().entrySet()) {
370      String t = (String) entry.getKey();
371      TableDescriptor nchtd = entry.getValue();
372      assertTrue((nchtd.equals(chtds.get(TableName.valueOf(t)))),
373        "expected " + htd.toString() + " got: " + chtds.get(TableName.valueOf(t)).toString());
374    }
375    // this is by design, for FSTableDescriptor with cache enabled, once we have done a full scan
376    // and load all the table descriptors to cache, we will not go to file system again, as the only
377    // way to update table descriptor is to through us so we can cache it when updating.
378    assertNotNull(nonchtds.get(random));
379    assertNull(chtds.get(random));
380  }
381
382  @Test
383  public void testNoSuchTable() throws IOException {
384    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
385    // Cleanup old tests if any detrius laying around.
386    TableDescriptors htds = new FSTableDescriptors(fs, testDir);
387    assertNull(htds.get(TableName.valueOf("NoSuchTable")),
388      "There shouldn't be any HTD for this table");
389  }
390
391  @Test
392  public void testUpdates(TestInfo testInfo) throws IOException {
393    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
394    // Cleanup old tests if any detrius laying around.
395    TableDescriptors htds = new FSTableDescriptors(fs, testDir);
396    TableDescriptor htd = TableDescriptorBuilder
397      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
398    htds.update(htd);
399    htds.update(htd);
400    htds.update(htd);
401  }
402
403  @Test
404  public void testTableInfoFileStatusComparator() {
405    FileStatus bare = new FileStatus(0, false, 0, 0, -1,
406      new Path("/tmp", FSTableDescriptors.TABLEINFO_FILE_PREFIX));
407    FileStatus future = new FileStatus(0, false, 0, 0, -1,
408      new Path("/tmp/tablinfo." + EnvironmentEdgeManager.currentTime()));
409    FileStatus farFuture = new FileStatus(0, false, 0, 0, -1,
410      new Path("/tmp/tablinfo." + EnvironmentEdgeManager.currentTime() + 1000));
411    FileStatus[] alist = { bare, future, farFuture };
412    FileStatus[] blist = { bare, farFuture, future };
413    FileStatus[] clist = { farFuture, bare, future };
414    Comparator<FileStatus> c = FSTableDescriptors.TABLEINFO_FILESTATUS_COMPARATOR;
415    Arrays.sort(alist, c);
416    Arrays.sort(blist, c);
417    Arrays.sort(clist, c);
418    // Now assert all sorted same in way we want.
419    for (int i = 0; i < alist.length; i++) {
420      assertTrue(alist[i].equals(blist[i]));
421      assertTrue(blist[i].equals(clist[i]));
422      assertTrue(clist[i].equals(i == 0 ? farFuture : i == 1 ? future : bare));
423    }
424  }
425
426  @Test
427  public void testReadingInvalidDirectoryFromFS() throws IOException {
428    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
429    try {
430      new FSTableDescriptors(fs, CommonFSUtils.getRootDir(UTIL.getConfiguration()))
431        .get(TableName.valueOf(HConstants.HBASE_TEMP_DIRECTORY));
432      fail("Shouldn't be able to read a table descriptor for the archive directory.");
433    } catch (Exception e) {
434      LOG.debug("Correctly got error when reading a table descriptor from the archive directory: "
435        + e.getMessage());
436    }
437  }
438
439  @Test
440  public void testCreateTableDescriptorUpdatesIfExistsAlready(TestInfo testInfo)
441    throws IOException {
442    TableDescriptor htd = TableDescriptorBuilder
443      .newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName())).build();
444    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
445    FSTableDescriptors fstd = new FSTableDescriptors(fs, testDir);
446    assertTrue(fstd.createTableDescriptor(htd));
447    assertFalse(fstd.createTableDescriptor(htd));
448    htd = TableDescriptorBuilder.newBuilder(htd)
449      .setValue(Bytes.toBytes("mykey"), Bytes.toBytes("myValue")).build();
450    assertTrue(fstd.createTableDescriptor(htd)); // this will re-create
451    Path tableDir = CommonFSUtils.getTableDir(testDir, htd.getTableName());
452    assertEquals(htd, FSTableDescriptors.getTableDescriptorFromFs(fs, tableDir));
453  }
454
455  @Test
456  public void testIgnoreBrokenTableDescriptorFiles(TestInfo testInfo) throws IOException {
457    TableDescriptor htd =
458      TableDescriptorBuilder.newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName()))
459        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("cf")).build();
460    TableDescriptor newHtd =
461      TableDescriptorBuilder.newBuilder(TableName.valueOf(testInfo.getTestMethod().get().getName()))
462        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("cf2")).build();
463    assertNotEquals(newHtd, htd);
464    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
465    FSTableDescriptors fstd = new FSTableDescriptors(fs, testDir, false, false);
466    fstd.update(htd);
467    byte[] bytes = TableDescriptorBuilder.toByteArray(newHtd);
468    Path tableDir = CommonFSUtils.getTableDir(testDir, htd.getTableName());
469    Path tableInfoDir = new Path(tableDir, FSTableDescriptors.TABLEINFO_DIR);
470    FileStatus[] statuses = fs.listStatus(tableInfoDir);
471    assertEquals(1, statuses.length);
472    int seqId =
473      FSTableDescriptors.getTableInfoSequenceIdAndFileLength(statuses[0].getPath()).sequenceId + 1;
474    Path brokenFile = new Path(tableInfoDir, FSTableDescriptors.getTableInfoFileName(seqId, bytes));
475    try (FSDataOutputStream out = fs.create(brokenFile)) {
476      out.write(bytes, 0, bytes.length / 2);
477    }
478    assertTrue(fs.exists(brokenFile));
479    TableDescriptor getTd = fstd.get(htd.getTableName());
480    assertEquals(htd, getTd);
481    assertFalse(fs.exists(brokenFile));
482  }
483
484  private static class FSTableDescriptorsTest extends FSTableDescriptors {
485
486    public FSTableDescriptorsTest(FileSystem fs, Path rootdir) {
487      this(fs, rootdir, true);
488    }
489
490    public FSTableDescriptorsTest(FileSystem fs, Path rootdir, boolean usecache) {
491      super(fs, rootdir, false, usecache);
492    }
493
494    public FSTableDescriptorsTest(FileSystem fs, Path rootdir, boolean usecache,
495      int tableDescriptorParallelLoadThreads) {
496      super(fs, rootdir, false, usecache, tableDescriptorParallelLoadThreads);
497    }
498
499    @Override
500    public TableDescriptor get(TableName tablename) {
501      LOG.info((super.isUsecache() ? "Cached" : "Non-Cached") + " TableDescriptor.get() on "
502        + tablename + ", cachehits=" + this.cachehits);
503      return super.get(tablename);
504    }
505  }
506}