content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.journal.ufs;
  
  import static org.junit.Assert.assertThrows;
  import static org.junit.Assert.assertTrue;
  
  import alluxio.exception.status.UnavailableException;
  import alluxio.master.journal.CatchupFuture;
  import alluxio.master.journal.CountingNoopFileSystemMaster;
  import alluxio.proto.journal.Journal;
  import alluxio.util.CommonUtils;
  import alluxio.util.URIUtils;
  import alluxio.util.WaitForOptions;
  
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.rules.TemporaryFolder;
  
  import java.io.File;
  import java.net.URI;
  import java.util.Collections;
  
  /**
   * Unit tests for {@link UfsJournal}.
   */
  public final class UfsJournalTest {
    @Rule
    public TemporaryFolder mFolder = new TemporaryFolder();
  
    @Rule
    public ExpectedException mThrown = ExpectedException.none();
  
    private UfsJournal mJournal;
    private CountingNoopFileSystemMaster mFileSystemMaster;
  
    @Before
    public void before() throws Exception {
      mFileSystemMaster = new CountingNoopFileSystemMaster();
      mJournal =
          new UfsJournal(URIUtils.appendPathOrDie(new URI(mFolder.newFolder().getAbsolutePath()),
              "FileSystemMaster"), mFileSystemMaster, 0, Collections::emptySet);
    }
  
    /**
     * Tests formatting journal.
     */
    @Test
    public void format() throws Exception {
      mJournal.getUfs().create(UfsJournalFile.encodeCheckpointFileLocation(mJournal, 0x12).toString())
          .close();
      mJournal.getUfs()
          .create(UfsJournalFile.encodeTemporaryCheckpointFileLocation(mJournal).toString()).close();
  
      long start = 0x11;
      for (int i = 0; i < 10; i++) {
        String l =
            UfsJournalFile.encodeLogFileLocation(mJournal, start + i, start + i + 2).toString();
        mJournal.getUfs().create(l).close();
        start = start + i + 2;
      }
      String currentLog =
          UfsJournalFile.encodeLogFileLocation(mJournal, start, UfsJournal.UNKNOWN_SEQUENCE_NUMBER)
              .toString();
      mJournal.getUfs().create(currentLog).close();
      // Write a malformed log file which should be skipped.
      mJournal.getUfs()
          .create(UfsJournalFile.encodeLogFileLocation(mJournal, 0x10, 0x100).toString() + ".tmp")
          .close();
  
      mJournal.format();
      Assert.assertTrue(mJournal.isFormatted());
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      Assert.assertTrue(snapshot.getCheckpoints().isEmpty());
      Assert.assertTrue(snapshot.getLogs().isEmpty());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    @Test
    public void unavailableAfterClose() throws Exception {
      mJournal.start();
      mJournal.close();
      mThrown.expect(UnavailableException.class);
      mJournal.createJournalContext();
    }
  
    @Test
    public void suspendNotAllowedOnPrimary() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
      mThrown.expect(IllegalStateException.class);
      mJournal.suspend();
    }
  
    @Test
    public void suspendCatchupResume() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = new CountingNoopFileSystemMaster();
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Bring current next sequence to 3.
      mJournal.write(Journal.JournalEntry.getDefaultInstance()); // seq-0
      mJournal.write(Journal.JournalEntry.getDefaultInstance()); // seq-1
      mJournal.write(Journal.JournalEntry.getDefaultInstance()); // seq-2
      mJournal.flush();
      // Standby still hasn't seen the updates since the current journal file is not complete.
      standbyJournal.suspend();
      // Write more entries while standby is at backup mode.
      mJournal.write(Journal.JournalEntry.getDefaultInstance()); // seq-3
      mJournal.write(Journal.JournalEntry.getDefaultInstance()); // seq-4
      mJournal.flush();
      // Resume until sequence-1.
      standbyJournal.catchup(1).waitTermination();
      // Entries still reside in an incomplete journal file.
      // After backup, we should have read only up to sequence-1.
      Assert.assertEquals(2, countingMaster.getApplyCount());
      // Initiate primary journal shutdown.
      // Current journal file will be completed and standby should still be suspended.
      mJournal.close();
      Assert.assertEquals(2, countingMaster.getApplyCount());
      // standby should apply new entries after resumed.
      standbyJournal.resume();
      CommonUtils.waitFor("catching up to current state", () -> countingMaster.getApplyCount() == 5);
    }
  
    @Test
    public void journalInitialReplay() throws Exception {
      Assert.assertEquals(UfsJournalCheckpointThread.CatchupState.NOT_STARTED,
          mJournal.getCatchupState());
      mJournal.start();
      CommonUtils.waitFor("catchup done", () -> mJournal.getCatchupState()
              == UfsJournalCheckpointThread.CatchupState.DONE,
          WaitForOptions.defaults().setTimeoutMs(6000));
      mJournal.gainPrimacy();
      Assert.assertEquals(UfsJournalCheckpointThread.CatchupState.NOT_STARTED,
          mJournal.getCatchupState());
      // Write entries and close to guarantee it's a complete journal file
      int entryCount = 10;
      for (int i = 0; i < entryCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      mJournal.flush();
      mJournal.close();
  
      // Validate the initial replay finished and applied all entries
      // Create a new Journal with the same journal path
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      mJournal =
          new UfsJournal(new URI(parentPath), mFileSystemMaster, 0, Collections::emptySet);
      mJournal.start();
      CommonUtils.waitFor("catchup done", () -> mJournal.getCatchupState()
              == UfsJournalCheckpointThread.CatchupState.DONE,
          WaitForOptions.defaults().setTimeoutMs(6000));
      Assert.assertEquals(entryCount, mFileSystemMaster.getApplyCount());
    }
  
    @Test
    public void journalStandbyCatchup() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
      UfsJournalLogWriter writer = new UfsJournalLogWriter(mJournal, 0);
      int entryCount = 10;
      for (long i = 0; i < 10; i++) {
        writer.write(Journal.JournalEntry.newBuilder().setSequenceNumber(i).build());
      }
      writer.close();
      mJournal.signalLosePrimacy();
      Assert.assertEquals(0, mFileSystemMaster.getApplyCount());
      mJournal.awaitLosePrimacy();
      // When master steps down, it should start catching up
      CommonUtils.waitFor("catchup done", () -> mJournal.getCatchupState()
              == UfsJournalCheckpointThread.CatchupState.DONE,
          WaitForOptions.defaults().setTimeoutMs(6000));
      // check if logs are applied
      Assert.assertEquals(entryCount, mFileSystemMaster.getApplyCount());
    }
  
    @Test
    public void gainPrimacyAfterSuspend() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = new CountingNoopFileSystemMaster();
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Suspend standby journal
      standbyJournal.suspend();
  
      // Write entries
      int entryCount = 10;
      for (int i = 0; i < entryCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      mJournal.flush();
      // Validate standby didn't apply any entries yet.
      Assert.assertEquals(0, countingMaster.getApplyCount());
  
      // Gain primacy.
      standbyJournal.gainPrimacy();
      CommonUtils.waitFor("catching up to current state",
          () -> countingMaster.getApplyCount() == entryCount);
  
      // Resume should fail after becoming primary.
      mThrown.expect(IllegalStateException.class);
      standbyJournal.resume();
    }
  
    @Test
    public void subsequentCatchups() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = new CountingNoopFileSystemMaster();
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Suspend standby journal.
      standbyJournal.suspend();
  
      // Write 2 batches of entries.
      int entryBatchCount = 5;
      for (int i = 0; i < 2 * entryBatchCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      mJournal.flush();
      // Validate standby didn't apply any entries yet.
      Assert.assertEquals(0, countingMaster.getApplyCount());
  
      // Catch up follower journal system to first batch of entries.
      standbyJournal.catchup(entryBatchCount - 1).waitTermination();
      Assert.assertEquals(entryBatchCount, countingMaster.getApplyCount());
      // Catch up follower journal system to second batch of entries.
      standbyJournal.catchup((2 * entryBatchCount) - 1).waitTermination();
      Assert.assertEquals(2 * entryBatchCount, countingMaster.getApplyCount());
    }
  
    @Test
    public void gainPrimacyDuringCatchup() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = CountingNoopFileSystemMaster.withApplyDelay(50);
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Suspend standby journal.
      standbyJournal.suspend();
  
      // Write many entries to guarantee that advancing will be in progress
      // when gainPrimacy() is called.
      int entryCount = 10;
      for (int i = 0; i < entryCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      mJournal.flush();
      // Validate standby didn't apply any entries yet.
      Assert.assertEquals(0, countingMaster.getApplyCount());
  
      // Initiate catching up.
      standbyJournal.catchup(entryCount - 2);
  
      // Gain primacy.
      standbyJournal.gainPrimacy();
      CommonUtils.waitFor("catching up to current state",
          () -> countingMaster.getApplyCount() == entryCount);
    }
  
    @Test
    public void gainPrimacyAfterCatchup() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = new CountingNoopFileSystemMaster();
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Suspend standby journal.
      standbyJournal.suspend();
  
      // Write many entries to guarantee that advancing will be in progress
      // when gainPrimacy() is called.
      int entryCount = 10;
      for (int i = 0; i < entryCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      mJournal.flush();
      // Validate standby didn't apply any entries yet.
      Assert.assertEquals(0, countingMaster.getApplyCount());
  
      // Initiate and wait for catching up.
      standbyJournal.catchup(entryCount - 2).waitTermination();
      Assert.assertEquals(entryCount - 1, countingMaster.getApplyCount());
  
      // Gain primacy.
      standbyJournal.gainPrimacy();
      CommonUtils.waitFor("catching up to current state",
          () -> countingMaster.getApplyCount() == entryCount);
    }
  
    @Test
    public void catchupCorruptedEntry() throws Exception {
      mJournal.start();
      mJournal.gainPrimacy();
  
      // Create a counting master implementation that counts how many journal entries it processed.
      CountingNoopFileSystemMaster countingMaster = new CountingNoopFileSystemMaster();
      // Find journal base path for standby journal to consume the same journal files.
      String parentPath = new File(mJournal.getLocation().getPath()).getParent();
      UfsJournal standbyJournal =
          new UfsJournal(new URI(parentPath), countingMaster, 0, Collections::emptySet);
      standbyJournal.start();
  
      // Suspend standby journal.
      standbyJournal.suspend();
  
      int entryCount = 10;
      for (int i = 0; i < entryCount; i++) {
        mJournal.write(Journal.JournalEntry.getDefaultInstance());
      }
      // This one will corrupt the journal catch thread
      Journal.JournalEntry corruptedEntry = Journal.JournalEntry.newBuilder()
          .setSequenceNumber(entryCount + 1)
          .setDeleteFile(alluxio.proto.journal.File.DeleteFileEntry.newBuilder()
              .setId(4563728)
              .setPath("/crash")
              .build())
            .build();
      mJournal.write(corruptedEntry);
      mJournal.flush();
  
      // The standby catchup thread will crash and the exception will be
      // recovered on waitTermination()
      RuntimeException exception = assertThrows(RuntimeException.class, () -> {
        CatchupFuture future = standbyJournal.catchup(entryCount);
        future.waitTermination();
      });
      assertTrue(exception.getMessage()
          .contains(CountingNoopFileSystemMaster.ENTRY_DOES_NOT_EXIST));
    }
  }
  