/**
   * Checks that gets work for implicit txs.
   *
   * @param cache Cache to test.
   * @throws Exception If failed.
   */
  private void checkExplicitTx(Ignite ignite, IgniteCache<String, String> cache) throws Exception {
    IgniteCache<String, String> asyncCache = cache.withAsync();

    Transaction tx = ignite.transactions().txStart();

    try {
      assertNull(cache.get("key1"));

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.get("key2");

      assertNull(asyncCache.future().get());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      assertTrue(cache.getAll(F.asSet("key3", "key4")).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.getAll(F.asSet("key5", "key6"));

      assertTrue(((Map) asyncCache.future().get()).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      cache.put("key7", "key7");

      cache.remove("key7");

      assertNull(cache.get("key7"));

      tx.commit();
    } finally {
      tx.close();
    }

    checkEmpty(cache);
  }
  /**
   * Tests preset eviction policy.
   *
   * @throws Exception If failed.
   */
  private void checkPolicy0() throws Exception {
    for (TransactionConcurrency concurrency : TransactionConcurrency.values()) {
      txConcurrency = concurrency;

      for (TransactionIsolation isolation : TransactionIsolation.values()) {
        txIsolation = isolation;

        Ignite g = startGrids();

        IgniteCache<String, String> cache = g.cache(null);

        try {
          info(
              ">>> Checking policy [txConcurrency="
                  + txConcurrency
                  + ", txIsolation="
                  + txIsolation
                  + ", plc="
                  + plc
                  + ", nearPlc="
                  + nearPlc
                  + ']');

          checkExplicitTx(g, cache);

          checkImplicitTx(cache);
        } finally {
          stopAllGrids();
        }
      }
    }
  }
  /** {@inheritDoc} */
  @Override
  protected void beforeTestsStarted() throws Exception {
    chunk = new byte[128];

    for (int i = 0; i < chunk.length; i++) chunk[i] = (byte) i;

    Ignite igniteSecondary =
        startGridWithIgfs("grid-secondary", "igfs-secondary", PRIMARY, null, SECONDARY_REST_CFG);

    IgfsSecondaryFileSystem hadoopFs =
        new IgniteHadoopIgfsSecondaryFileSystem(SECONDARY_URI, SECONDARY_CFG);

    Ignite ignite = startGridWithIgfs("grid", "igfs", mode, hadoopFs, PRIMARY_REST_CFG);

    igfsSecondary = (IgfsImpl) igniteSecondary.fileSystem("igfs-secondary");
    igfs = (IgfsImpl) ignite.fileSystem("igfs");
  }
  /**
   * @param g Grid.
   * @throws Exception If failed.
   */
  private void checkNodes(Ignite g) throws Exception {
    IgniteCache<String, String> cache = g.cache("test");

    for (char c = 'a'; c <= 'z'; c++) {
      String key = Character.toString(c);

      cache.put(key, "val-" + key);

      String v1 = cache.get(key);
      String v2 = cache.get(key); // Get second time.

      info("v1: " + v1);
      info("v2: " + v2);

      assertNotNull(v1);
      assertNotNull(v2);

      if (affinity(cache).mapKeyToNode(key).isLocal()) assertSame(v1, v2);
      else assertEquals(v1, v2);
    }
  }