TransactionExecutorTest.java

/*
 * Copyright © 2012-2014 Cask Data, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package co.cask.tephra;

import co.cask.tephra.inmemory.InMemoryTxSystemClient;
import co.cask.tephra.runtime.ConfigModule;
import co.cask.tephra.runtime.DiscoveryModules;
import co.cask.tephra.runtime.TransactionModules;
import co.cask.tephra.snapshot.DefaultSnapshotCodec;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.inject.AbstractModule;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Singleton;
import com.google.inject.util.Modules;
import org.apache.hadoop.conf.Configuration;
import org.junit.Assert;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

import java.io.IOException;
import java.util.Collection;
import java.util.List;
import javax.annotation.Nullable;

/**
 * Tests the transaction executor.
 */
public class TransactionExecutorTest {
  private static DummyTxClient txClient;
  private static TransactionExecutorFactory factory;

  @ClassRule
  public static TemporaryFolder tmpFolder = new TemporaryFolder();

  @BeforeClass
  public static void setup() throws IOException {
    final Configuration conf = new Configuration();
    conf.set(TxConstants.Persist.CFG_TX_SNAPHOT_CODEC_CLASSES, DefaultSnapshotCodec.class.getName());
    conf.set(TxConstants.Manager.CFG_TX_SNAPSHOT_DIR, tmpFolder.newFolder().getAbsolutePath());
    Injector injector = Guice.createInjector(
      new ConfigModule(conf),
      new DiscoveryModules().getInMemoryModules(),
      Modules.override(
        new TransactionModules().getInMemoryModules()).with(new AbstractModule() {
        @Override
        protected void configure() {
          TransactionManager txManager = new TransactionManager(conf);
          txManager.startAndWait();
          bind(TransactionManager.class).toInstance(txManager);
          bind(TransactionSystemClient.class).to(DummyTxClient.class).in(Singleton.class);
        }
      }));

    txClient = (DummyTxClient) injector.getInstance(TransactionSystemClient.class);
    factory = injector.getInstance(TransactionExecutorFactory.class);
  }

  final DummyTxAware ds1 = new DummyTxAware(), ds2 = new DummyTxAware();
  final Collection<TransactionAware> txAwares = ImmutableList.<TransactionAware>of(ds1, ds2);

  private TransactionExecutor getExecutor() {
    return factory.createExecutor(txAwares);
  }

  private TransactionExecutor getExecutorWithNoRetry() {
    return new DefaultTransactionExecutor(txClient, txAwares, RetryStrategies.noRetries());
  }

  static final byte[] A = { 'a' };
  static final byte[] B = { 'b' };

  final TransactionExecutor.Function<Integer, Integer> testFunction =
    new TransactionExecutor.Function<Integer, Integer>() {
      @Override
      public Integer apply(@Nullable Integer input) {
        ds1.addChange(A);
        ds2.addChange(B);
        if (input == null) {
          throw new RuntimeException("function failed");
        }
        return input * input;
      }
  };

  @Before
  public void resetTxAwares() {
    ds1.reset();
    ds2.reset();
  }

  @Test
  public void testSuccessful() throws TransactionFailureException, InterruptedException {
    // execute: add a change to ds1 and ds2
    Integer result = getExecutor().execute(testFunction, 10);
    // verify both are committed and post-committed
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertTrue(ds2.committed);
    Assert.assertTrue(ds1.postCommitted);
    Assert.assertTrue(ds2.postCommitted);
    Assert.assertFalse(ds1.rolledBack);
    Assert.assertFalse(ds2.rolledBack);
    Assert.assertTrue(100 == result);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Committed);
  }

  @Test
  public void testPostCommitFailure() throws TransactionFailureException, InterruptedException {
    ds1.failPostCommitTxOnce = InduceFailure.ThrowException;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("post commit failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("post failure", e.getCause().getMessage());
    }
    // verify both are committed and post-committed
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertTrue(ds2.committed);
    Assert.assertTrue(ds1.postCommitted);
    Assert.assertTrue(ds2.postCommitted);
    Assert.assertFalse(ds1.rolledBack);
    Assert.assertFalse(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Committed);
  }

  @Test
  public void testPersistFailure() throws TransactionFailureException, InterruptedException {
    ds1.failCommitTxOnce = InduceFailure.ThrowException;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("persist failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("persist failure", e.getCause().getMessage());
    }
    // verify both are rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  @Test
  public void testPersistFalse() throws TransactionFailureException, InterruptedException {
    ds1.failCommitTxOnce = InduceFailure.ReturnFalse;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("persist failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertNull(e.getCause()); // in this case, the ds simply returned false
    }
    // verify both are rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  @Test
  public void testPersistAndRollbackFailure() throws TransactionFailureException, InterruptedException {
    ds1.failCommitTxOnce = InduceFailure.ThrowException;
    ds1.failRollbackTxOnce = InduceFailure.ThrowException;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("persist failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("persist failure", e.getCause().getMessage());
    }
    // verify both are rolled back and tx is invalidated
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Invalidated);
  }

  @Test
  public void testPersistAndRollbackFalse() throws TransactionFailureException, InterruptedException {
    ds1.failCommitTxOnce = InduceFailure.ReturnFalse;
    ds1.failRollbackTxOnce = InduceFailure.ReturnFalse;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("persist failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertNull(e.getCause()); // in this case, the ds simply returned false
    }
    // verify both are rolled back and tx is invalidated
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Invalidated);
  }

  @Test
  public void testNoIndefiniteRetryByDefault() throws TransactionFailureException, InterruptedException {
    // we want retry by default, so that engineers don't miss it
    txClient.failCommits = 1000;
    try {
      // execute: add a change to ds1 and ds2
      getExecutor().execute(testFunction, 10);
      Assert.fail("commit failed too many times to retry - exception should be thrown");
    } catch (TransactionConflictException e) {
      Assert.assertNull(e.getCause());
    }

    txClient.failCommits = 0;

    // verify both are rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertTrue(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  @Test
  public void testRetryByDefault() throws TransactionFailureException, InterruptedException {
    // we want retry by default, so that engineers don't miss it
    txClient.failCommits = 2;
    // execute: add a change to ds1 and ds2
    getExecutor().execute(testFunction, 10);
    // should not fail, but continue

    // verify both are committed
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertTrue(ds2.committed);
    Assert.assertTrue(ds1.postCommitted);
    Assert.assertTrue(ds2.postCommitted);
    Assert.assertFalse(ds1.rolledBack);
    Assert.assertFalse(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Committed);
  }

  @Test
  public void testCommitFalse() throws TransactionFailureException, InterruptedException {
    txClient.failCommits = 1;
    // execute: add a change to ds1 and ds2
    try {
      getExecutorWithNoRetry().execute(testFunction, 10);
      Assert.fail("commit failed - exception should be thrown");
    } catch (TransactionConflictException e) {
      Assert.assertNull(e.getCause());
    }
    // verify both are rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertTrue(ds1.committed);
    Assert.assertTrue(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  @Test
  public void testCanCommitFalse() throws TransactionFailureException, InterruptedException {
    txClient.failCanCommitOnce = true;
    // execute: add a change to ds1 and ds2
    try {
      getExecutorWithNoRetry().execute(testFunction, 10);
      Assert.fail("commit failed - exception should be thrown");
    } catch (TransactionConflictException e) {
      Assert.assertNull(e.getCause());
    }
    // verify both are rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertTrue(ds2.checked);
    Assert.assertFalse(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  @Test
  public void testChangesAndRollbackFailure() throws TransactionFailureException, InterruptedException {
    ds1.failChangesTxOnce = InduceFailure.ThrowException;
    ds1.failRollbackTxOnce = InduceFailure.ThrowException;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("get changes failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("changes failure", e.getCause().getMessage());
    }
    // verify both are rolled back and tx is invalidated
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertTrue(ds1.checked);
    Assert.assertFalse(ds2.checked);
    Assert.assertFalse(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Invalidated);
  }

  @Test
  public void testFunctionAndRollbackFailure() throws TransactionFailureException, InterruptedException {
    ds1.failRollbackTxOnce = InduceFailure.ReturnFalse;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, null);
      Assert.fail("function failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("function failed", e.getCause().getMessage());
    }
    // verify both are rolled back and tx is invalidated
    Assert.assertTrue(ds1.started);
    Assert.assertTrue(ds2.started);
    Assert.assertFalse(ds1.checked);
    Assert.assertFalse(ds2.checked);
    Assert.assertFalse(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertTrue(ds1.rolledBack);
    Assert.assertTrue(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Invalidated);
  }

  @Test
  public void testStartAndRollbackFailure() throws TransactionFailureException, InterruptedException {
    ds1.failStartTxOnce = InduceFailure.ThrowException;
    // execute: add a change to ds1 and ds2
    try {
      getExecutor().execute(testFunction, 10);
      Assert.fail("start failed - exception should be thrown");
    } catch (TransactionFailureException e) {
      Assert.assertEquals("start failure", e.getCause().getMessage());
    }
    // verify both are not rolled back and tx is aborted
    Assert.assertTrue(ds1.started);
    Assert.assertFalse(ds2.started);
    Assert.assertFalse(ds1.checked);
    Assert.assertFalse(ds2.checked);
    Assert.assertFalse(ds1.committed);
    Assert.assertFalse(ds2.committed);
    Assert.assertFalse(ds1.postCommitted);
    Assert.assertFalse(ds2.postCommitted);
    Assert.assertFalse(ds1.rolledBack);
    Assert.assertFalse(ds2.rolledBack);
    Assert.assertEquals(txClient.state, DummyTxClient.CommitState.Aborted);
  }

  enum InduceFailure { NoFailure, ReturnFalse, ThrowException }

  static class DummyTxAware implements TransactionAware {

    Transaction tx;
    boolean started = false;
    boolean committed = false;
    boolean checked = false;
    boolean rolledBack = false;
    boolean postCommitted = false;
    List<byte[]> changes = Lists.newArrayList();

    InduceFailure failStartTxOnce = InduceFailure.NoFailure;
    InduceFailure failChangesTxOnce = InduceFailure.NoFailure;
    InduceFailure failCommitTxOnce = InduceFailure.NoFailure;
    InduceFailure failPostCommitTxOnce = InduceFailure.NoFailure;
    InduceFailure failRollbackTxOnce = InduceFailure.NoFailure;

    void addChange(byte[] key) {
      changes.add(key);
    }

    void reset() {
      tx = null;
      started = false;
      checked = false;
      committed = false;
      rolledBack = false;
      postCommitted = false;
      changes.clear();
    }

    @Override
    public void startTx(Transaction tx) {
      reset();
      started = true;
      this.tx = tx;
      if (failStartTxOnce == InduceFailure.ThrowException) {
        failStartTxOnce = InduceFailure.NoFailure;
        throw new RuntimeException("start failure");
      }
    }

    @Override
    public void updateTx(Transaction tx) {
      this.tx = tx;
    }

    @Override
    public Collection<byte[]> getTxChanges() {
      checked = true;
      if (failChangesTxOnce == InduceFailure.ThrowException) {
        failChangesTxOnce = InduceFailure.NoFailure;
        throw new RuntimeException("changes failure");
      }
      return ImmutableList.copyOf(changes);
    }

    @Override
    public boolean commitTx() throws Exception {
      committed = true;
      if (failCommitTxOnce == InduceFailure.ThrowException) {
        failCommitTxOnce = InduceFailure.NoFailure;
        throw new RuntimeException("persist failure");
      }
      if (failCommitTxOnce == InduceFailure.ReturnFalse) {
        failCommitTxOnce = InduceFailure.NoFailure;
        return false;
      }
      return true;
    }

    @Override
    public void postTxCommit() {
      postCommitted = true;
      if (failPostCommitTxOnce == InduceFailure.ThrowException) {
        failPostCommitTxOnce = InduceFailure.NoFailure;
        throw new RuntimeException("post failure");
      }
    }

    @Override
    public boolean rollbackTx() throws Exception {
      rolledBack = true;
      if (failRollbackTxOnce == InduceFailure.ThrowException) {
        failRollbackTxOnce = InduceFailure.NoFailure;
        throw new RuntimeException("rollback failure");
      }
      if (failRollbackTxOnce == InduceFailure.ReturnFalse) {
        failRollbackTxOnce = InduceFailure.NoFailure;
        return false;
      }
      return true;
    }

    @Override
    public String getTransactionAwareName() {
      return "dummy";
    }
  }

  static class DummyTxClient extends InMemoryTxSystemClient {

    boolean failCanCommitOnce = false;
    int failCommits = 0;
    enum CommitState {
      Started, Committed, Aborted, Invalidated
    }
    CommitState state = CommitState.Started;

    @Inject
    DummyTxClient(TransactionManager txmgr) {
      super(txmgr);
    }

    @Override
    public boolean canCommit(Transaction tx, Collection<byte[]> changeIds) throws TransactionNotInProgressException {
      if (failCanCommitOnce) {
        failCanCommitOnce = false;
        return false;
      } else {
        return super.canCommit(tx, changeIds);
      }
    }

    @Override
    public boolean commit(Transaction tx) throws TransactionNotInProgressException {
      if (failCommits-- > 0) {
        return false;
      } else {
        state = CommitState.Committed;
        return super.commit(tx);
      }
    }

    @Override
    public Transaction startLong() {
      state = CommitState.Started;
      return super.startLong();
    }

    @Override
    public Transaction startShort() {
      state = CommitState.Started;
      return super.startShort();
    }

    @Override
    public Transaction startShort(int timeout) {
      state = CommitState.Started;
      return super.startShort(timeout);
    }

    @Override
    public void abort(Transaction tx) {
      state = CommitState.Aborted;
      super.abort(tx);
    }

    @Override
    public boolean invalidate(long tx) {
      state = CommitState.Invalidated;
      return super.invalidate(tx);
    }
  }
}