private ScanResult getHashNumberRangeKeyItems(String[] hashKeys, String hashType) {
  List<Map<String, AttributeValue>> items = new ArrayList<>();
  for (String key : hashKeys) {
    for (Integer i = 0; i < NUM_RANGE_KEYS_PER_HASH_KEY; i++) {
      Map<String, AttributeValue> item = new HashMap<>();
      if (hashType.equals("S")) {
        item.put("hashKey", new AttributeValue(key));
      } else {
        item.put("hashKey", new AttributeValue().withN(key));
      }
      item.put("rangeKey", new AttributeValue().withN("0" + i.toString()));
      items.add(item);
    }
  }
  return new ScanResult().withScannedCount(items.size()).withItems(items).withConsumedCapacity
      (new ConsumedCapacity().withCapacityUnits(1d));
}
 

@Override
public QueryResultWrapper next() throws BackendException {
    final Query backoff = new ExponentialBackoff.Query(request, delegate, permitsToConsume);
    final QueryResult result = backoff.runWithBackoff();
    final ConsumedCapacity consumedCapacity = result.getConsumedCapacity();
    if (null != consumedCapacity) {
        permitsToConsume = Math.max((int) (consumedCapacity.getCapacityUnits() - 1.0), 1);
        totalCapacityUnits += consumedCapacity.getCapacityUnits();
    }

    if (result.getLastEvaluatedKey() != null && !result.getLastEvaluatedKey().isEmpty()) {
        request.setExclusiveStartKey(result.getLastEvaluatedKey());
    } else {
        markComplete();
    }
    // a update returned count
    returnedCount += result.getCount();

    // b update scanned count
    scannedCount += result.getScannedCount();
    // c add scanned finalItemList
    finalItemList.addAll(result.getItems());
    return new QueryResultWrapper(titanKey, result);
}
 

@Override
public void write(K key, V value) throws IOException {
  if (value == null) {
    throw new RuntimeException("Null record encountered. At least the key columns must be "
        + "specified.");
  }

  verifyInterval();
  if (progressable != null) {
    progressable.progress();
  }

  DynamoDBItemWritable item = convertValueToDynamoDBItem(key, value);
  BatchWriteItemResult result = client.putBatch(tableName, item.getItem(),
      permissibleWritesPerSecond - writesPerSecond, reporter, deletionMode);

  batchSize++;
  totalItemsWritten++;

  if (result != null) {
    if (result.getConsumedCapacity() != null) {
      for (ConsumedCapacity consumedCapacity : result.getConsumedCapacity()) {
        double consumedUnits = consumedCapacity.getCapacityUnits();
        totalIOPSConsumed += consumedUnits;
      }
    }

    int unprocessedItems = 0;
    for (List<WriteRequest> requests : result.getUnprocessedItems().values()) {
      unprocessedItems += requests.size();
    }
    writesPerSecond += batchSize - unprocessedItems;
    batchSize = unprocessedItems;
  }
}
 

private ScanResult getHashKeyItems(String[] hashKeys, String type) {
  List<Map<String, AttributeValue>> items = new ArrayList<>();
  for (String key : hashKeys) {
    Map<String, AttributeValue> item = new HashMap<>();
    if (type.equals("S")) {
      item.put("hashKey", new AttributeValue(key));
    } else {
      item.put("hashKey", new AttributeValue().withN(key));
    }
    items.add(item);
  }
  return new ScanResult().withScannedCount(items.size()).withItems(items).withConsumedCapacity
      (new ConsumedCapacity().withCapacityUnits(1d));
}
 

@Override
protected QueryResultWrapper getMergedPages() {
    final QueryResult mergedDynamoResult = new QueryResult().withItems(getFinalItemList())
                                                      .withCount(returnedCount)
                                                      .withScannedCount(scannedCount)
                                                      .withConsumedCapacity(new ConsumedCapacity()
                                                                                    .withTableName(request.getTableName())
                                                                                    .withCapacityUnits(totalCapacityUnits));
    return new QueryResultWrapper(titanKey, mergedDynamoResult);
}
 

@Override
public SegmentedScanResult call() {
    ScanResult result = null;
    result = runWithBackoff();

    final ConsumedCapacity cc = result.getConsumedCapacity();

    if (cc != null && cc.getCapacityUnits() != null) {
        lastConsumedCapacity = result.getConsumedCapacity()
                .getCapacityUnits().intValue();
    } else if (result.getScannedCount() != null && result.getCount() != null) {

        final boolean isConsistent = request.getConsistentRead();
        int itemSize = isConsistent ? BootstrapConstants.STRONGLY_CONSISTENT_READ_ITEM_SIZE
                : BootstrapConstants.EVENTUALLY_CONSISTENT_READ_ITEM_SIZE;

        lastConsumedCapacity = (result.getScannedCount() / (int) Math.max(1.0, result.getCount()))
                * (ItemSizeCalculator.calculateScanResultSizeInBytes(result) / itemSize);
    }

    if (result.getLastEvaluatedKey() != null
            && !result.getLastEvaluatedKey().isEmpty()) {
        hasNext = true;
        request.setExclusiveStartKey(result.getLastEvaluatedKey());
    } else {
        hasNext = false;
    }

    if (lastConsumedCapacity > 0) {
        rateLimiter.acquire(lastConsumedCapacity);
    }
    return new SegmentedScanResult(result, request.getSegment());
}
 

/**
 * Batch writes the write request to the DynamoDB endpoint and THEN acquires
 * permits equal to the consumed capacity of the write.
 */
@Override
public Void call() {
    List<ConsumedCapacity> batchResult = runWithBackoff(batch);
    Iterator<ConsumedCapacity> it = batchResult.iterator();
    int consumedCapacity = 0;
    while (it.hasNext()) {
        consumedCapacity += it.next().getCapacityUnits().intValue();
    }
    rateLimiter.acquire(consumedCapacity);
    return null;
}
 

/**
 * Writes to DynamoDBTable using an exponential backoff. If the
 * batchWriteItem returns unprocessed items then it will exponentially
 * backoff and retry the unprocessed items.
 */
public List<ConsumedCapacity> runWithBackoff(BatchWriteItemRequest req) {
    BatchWriteItemResult writeItemResult = null;
    List<ConsumedCapacity> consumedCapacities = new LinkedList<ConsumedCapacity>();
    Map<String, List<WriteRequest>> unprocessedItems = null;
    boolean interrupted = false;
    try {
        do {
            writeItemResult = client.batchWriteItem(req);
            unprocessedItems = writeItemResult.getUnprocessedItems();
            consumedCapacities
                    .addAll(writeItemResult.getConsumedCapacity());

            if (unprocessedItems != null) {
                req.setRequestItems(unprocessedItems);
                try {
                    Thread.sleep(exponentialBackoffTime);
                } catch (InterruptedException ie) {
                    interrupted = true;
                } finally {
                    exponentialBackoffTime *= 2;
                    if (exponentialBackoffTime > BootstrapConstants.MAX_EXPONENTIAL_BACKOFF_TIME) {
                        exponentialBackoffTime = BootstrapConstants.MAX_EXPONENTIAL_BACKOFF_TIME;
                    }
                }
            }
        } while (unprocessedItems != null && unprocessedItems.get(tableName) != null);
        return consumedCapacities;
    } finally {
        if (interrupted) {
            Thread.currentThread().interrupt();
        }
    }
}
 

@Test
public void test_batchWriteItem_WithAllParameters() throws Exception {
  createTable();

  String TEST_ATTRIBUTE_2 = "Attribute2";
  String TEST_ATTRIBUTE_VALUE_2 = "AttributeValue2";

  Map<String, List<WriteRequest>> requestItems = new HashMap<String, List<WriteRequest>>();
  List<WriteRequest> writeRequests = new ArrayList<WriteRequest>();

  Map<String, AttributeValue> item1 = new HashMap<String, AttributeValue>();
  item1.put(TEST_ATTRIBUTE, new AttributeValue()
    .withS(TEST_ATTRIBUTE_VALUE));
  WriteRequest writeRequest1 = new WriteRequest()
    .withPutRequest(new PutRequest()
      .withItem(item1));
  writeRequests.add(writeRequest1);

  Map<String, AttributeValue> item2 = new HashMap<String, AttributeValue>();
  item2.put(TEST_ATTRIBUTE_2, new AttributeValue()
    .withS(TEST_ATTRIBUTE_VALUE_2));
  WriteRequest writeRequest2 = new WriteRequest()
    .withPutRequest(new PutRequest()
      .withItem(item2));
  writeRequests.add(writeRequest2);

  requestItems.put(TEST_TABLE_NAME, writeRequests);

  BatchWriteItemResult result = dynamoDb.batchWriteItem(requestItems);
  List<ConsumedCapacity> consumedCapacities = result.getConsumedCapacity();

  assertThat(consumedCapacities.size(), equalTo(writeRequests.size()));
}
 

private static void writeMultipleItemsBatchWrite() {
    try {

        // Create a map for the requests in the batch
        Map<String, List<WriteRequest>> requestItems = new HashMap<String, List<WriteRequest>>();

        // Create a PutRequest for a new Forum item
        Map<String, AttributeValue> forumItem = new HashMap<String, AttributeValue>();
        forumItem.put("Name", new AttributeValue().withS("Amazon RDS"));
        forumItem.put("Threads", new AttributeValue().withN("0"));

        List<WriteRequest> forumList = new ArrayList<WriteRequest>();
        forumList.add(new WriteRequest().withPutRequest(new PutRequest().withItem(forumItem)));
        requestItems.put(table1Name, forumList);

        // Create a PutRequest for a new Thread item
        Map<String, AttributeValue> threadItem = new HashMap<String, AttributeValue>();
        threadItem.put("ForumName", new AttributeValue().withS("Amazon RDS"));
        threadItem.put("Subject", new AttributeValue().withS("Amazon RDS Thread 1"));
        threadItem.put("Message", new AttributeValue().withS("ElastiCache Thread 1 message"));
        threadItem.put("KeywordTags", new AttributeValue().withSS(Arrays.asList("cache", "in-memory")));

        List<WriteRequest> threadList = new ArrayList<WriteRequest>();
        threadList.add(new WriteRequest().withPutRequest(new PutRequest().withItem(threadItem)));

        // Create a DeleteRequest for a Thread item
        Map<String, AttributeValue> threadDeleteKey = new HashMap<String, AttributeValue>();
        threadDeleteKey.put("ForumName", new AttributeValue().withS("Amazon S3"));
        threadDeleteKey.put("Subject", new AttributeValue().withS("S3 Thread 100"));

        threadList.add(new WriteRequest().withDeleteRequest(new DeleteRequest().withKey(threadDeleteKey)));
        requestItems.put(table2Name, threadList);

        BatchWriteItemResult result;
        BatchWriteItemRequest batchWriteItemRequest = new BatchWriteItemRequest()
            .withReturnConsumedCapacity(ReturnConsumedCapacity.TOTAL);

        do {
            System.out.println("Making the request.");

            batchWriteItemRequest.withRequestItems(requestItems);
            result = client.batchWriteItem(batchWriteItemRequest);

            // Print consumed capacity units
            for (ConsumedCapacity consumedCapacity : result.getConsumedCapacity()) {
                String tableName = consumedCapacity.getTableName();
                Double consumedCapacityUnits = consumedCapacity.getCapacityUnits();
                System.out.println("Consumed capacity units for table " + tableName + ": " + consumedCapacityUnits);
            }

            // Check for unprocessed keys which could happen if you exceed
            // provisioned throughput
            System.out.println("Unprocessed Put and Delete requests: \n" + result.getUnprocessedItems());
            requestItems = result.getUnprocessedItems();
        } while (result.getUnprocessedItems().size() > 0);

    }
    catch (AmazonServiceException ase) {
        System.err.println("Failed to retrieve items: ");
        ase.printStackTrace(System.err);
    }

}
 

public BatchWriteItemResult batchWriteItem(final BatchWriteItemRequest batchRequest) throws BackendException {
    int count = 0;
    for (Entry<String, List<WriteRequest>> entry : batchRequest.getRequestItems().entrySet()) {
        final String tableName = entry.getKey();
        final List<WriteRequest> requests = entry.getValue();
        count += requests.size();
        if (count > BATCH_WRITE_MAX_NUMBER_OF_ITEMS) {
            throw new IllegalArgumentException("cant have more than 25 requests in a batchwrite");
        }
        for (final WriteRequest request : requests) {
            if ((request.getPutRequest() != null) == (request.getDeleteRequest() != null)) {
                throw new IllegalArgumentException("Exactly one of PutRequest or DeleteRequest must be set in each WriteRequest in a batch write operation");
            }
            final int wcu;
            final String apiName;
            if (request.getPutRequest() != null) {
                apiName = PUT_ITEM;
                final int bytes = calculateItemSizeInBytes(request.getPutRequest().getItem());
                wcu = computeWcu(bytes);
            } else { //deleterequest
                apiName = DELETE_ITEM;
                wcu = estimateCapacityUnits(apiName, tableName);
            }
            timedWriteThrottle(apiName, tableName, wcu);
        }
    }

    BatchWriteItemResult result;
    setUserAgent(batchRequest);
    final Timer.Context apiTimerContext = getTimerContext(BATCH_WRITE_ITEM, null /*tableName*/);
    try {
        result = client.batchWriteItem(batchRequest);
    } catch (Exception e) {
        throw processDynamoDbApiException(e, BATCH_WRITE_ITEM, null /*tableName*/);
    } finally {
        apiTimerContext.stop();
    }
    if (result.getConsumedCapacity() != null) {
        for (ConsumedCapacity ccu : result.getConsumedCapacity()) {
            meterConsumedCapacity(BATCH_WRITE_ITEM, ccu);
        }
    }
    return result;
}
 

private void meterConsumedCapacity(final String apiName, final ConsumedCapacity ccu) {
    if (ccu != null) {
        getConsumedCapacityMeter(apiName, ccu.getTableName()).mark(Math.round(ccu.getCapacityUnits()));
    }
}
 

private static void writeMultipleItemsBatchWrite() {
    try {                    
        
       // Create a map for the requests in the batch
       Map<String, List<WriteRequest>> requestItems = new HashMap<String, List<WriteRequest>>();
        
       // Create a PutRequest for a new Forum item
       Map<String, AttributeValue> forumItem = new HashMap<String, AttributeValue>();
       forumItem.put("Name", new AttributeValue().withS("Amazon RDS"));
       forumItem.put("Threads", new AttributeValue().withN("0"));
    
       List<WriteRequest> forumList = new ArrayList<WriteRequest>();
       forumList.add(new WriteRequest().withPutRequest(new PutRequest().withItem(forumItem)));
       requestItems.put(table1Name, forumList);
       
       // Create a PutRequest for a new Thread item
       Map<String, AttributeValue> threadItem = new HashMap<String, AttributeValue>();
       threadItem.put("ForumName", new AttributeValue().withS("Amazon RDS"));
       threadItem.put("Subject", new AttributeValue().withS("Amazon RDS Thread 1"));
       threadItem.put("Message", new AttributeValue().withS("ElasticCache Thread 1 message"));
       threadItem.put("KeywordTags", new AttributeValue().withSS(Arrays.asList("cache", "in-memory")));
    
       List<WriteRequest> threadList = new ArrayList<WriteRequest>();
       threadList.add(new WriteRequest().withPutRequest(new PutRequest().withItem(threadItem)));
       
       // Create a DeleteRequest for a Thread item
       Map<String, AttributeValue> threadDeleteKey = new HashMap<String, AttributeValue>(); 
       threadDeleteKey.put("ForumName", new AttributeValue().withS("Amazon S3"));
       threadDeleteKey.put("Subject", new AttributeValue().withS("S3 Thread 100"));
       
       threadList.add(new WriteRequest().withDeleteRequest(new DeleteRequest().withKey(threadDeleteKey)));
       requestItems.put(table2Name, threadList);
       
       BatchWriteItemResult result;
       BatchWriteItemRequest batchWriteItemRequest = new BatchWriteItemRequest()
           .withReturnConsumedCapacity(ReturnConsumedCapacity.TOTAL);
       
       do {
           System.out.println("Making the request.");
                           
           batchWriteItemRequest.withRequestItems(requestItems);
           result = client.batchWriteItem(batchWriteItemRequest);
           
           // Print consumed capacity units
           for(ConsumedCapacity consumedCapacity : result.getConsumedCapacity()) {
                String tableName = consumedCapacity.getTableName();
                Double consumedCapacityUnits = consumedCapacity.getCapacityUnits();
                System.out.println("Consumed capacity units for table " + tableName + ": " + consumedCapacityUnits);
           }
           
           // Check for unprocessed keys which could happen if you exceed provisioned throughput
           System.out.println("Unprocessed Put and Delete requests: \n" + result.getUnprocessedItems());
           requestItems = result.getUnprocessedItems();
       } while (result.getUnprocessedItems().size() > 0);
                    
    }  catch (AmazonServiceException ase) {
        System.err.println("Failed to retrieve items: ");
        ase.printStackTrace(System.err);
    }  

}