使用 Amazon SDK 通过 DAX 加快 DynamoDB 读取速度

使用 DAX 或 Boto3 客户端创建一个表。

import boto3


def create_dax_table(dyn_resource=None):
    """
    Creates a DynamoDB table.

    :param dyn_resource: Either a Boto3 or DAX resource.
    :return: The newly created table.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table_name = 'TryDaxTable'
    params = {
        'TableName': table_name,
        'KeySchema': [
            {'AttributeName': 'partition_key', 'KeyType': 'HASH'},
            {'AttributeName': 'sort_key', 'KeyType': 'RANGE'}
        ],
        'AttributeDefinitions': [
            {'AttributeName': 'partition_key', 'AttributeType': 'N'},
            {'AttributeName': 'sort_key', 'AttributeType': 'N'}
        ],
        'ProvisionedThroughput': {
            'ReadCapacityUnits': 10,
            'WriteCapacityUnits': 10
        }
    }
    table = dyn_resource.create_table(**params)
    print(f"Creating {table_name}...")
    table.wait_until_exists()
    return table


if __name__ == '__main__':
    dax_table = create_dax_table()
    print(f"Created table.")

将测试数据写入表中。

import boto3


def write_data_to_dax_table(key_count, item_size, dyn_resource=None):
    """
    Writes test data to the demonstration table.

    :param key_count: The number of partition and sort keys to use to populate the
                      table. The total number of items is key_count * key_count.
    :param item_size: The size of non-key data for each test item.
    :param dyn_resource: Either a Boto3 or DAX resource.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table = dyn_resource.Table('TryDaxTable')
    some_data = 'X' * item_size

    for partition_key in range(1, key_count + 1):
        for sort_key in range(1, key_count + 1):
            table.put_item(Item={
                'partition_key': partition_key,
                'sort_key': sort_key,
                'some_data': some_data
            })
            print(f"Put item ({partition_key}, {sort_key}) succeeded.")


if __name__ == '__main__':
    write_key_count = 10
    write_item_size = 1000
    print(f"Writing {write_key_count*write_key_count} items to the table. "
          f"Each item is {write_item_size} characters.")
    write_data_to_dax_table(write_key_count, write_item_size)

获取项目以查看 DAX 客户端和 Boto3 客户端的多次迭代，并报告每个客户端花费的时间。

import argparse
import sys
import time
import amazondax
import boto3


def get_item_test(key_count, iterations, dyn_resource=None):
    """
    Gets items from the table a specified number of times. The time before the
    first iteration and the time after the last iteration are both captured
    and reported.

    :param key_count: The number of items to get from the table in each iteration.
    :param iterations: The number of iterations to run.
    :param dyn_resource: Either a Boto3 or DAX resource.
    :return: The start and end times of the test.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table = dyn_resource.Table('TryDaxTable')
    start = time.perf_counter()
    for _ in range(iterations):
        for partition_key in range(1, key_count + 1):
            for sort_key in range(1, key_count + 1):
                table.get_item(Key={
                    'partition_key': partition_key,
                    'sort_key': sort_key
                })
                print('.', end='')
                sys.stdout.flush()
    print()
    end = time.perf_counter()
    return start, end


if __name__ == '__main__':
    # pylint: disable=not-context-manager
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'endpoint_url', nargs='?',
        help="When specified, the DAX cluster endpoint. Otherwise, DAX is not used.")
    args = parser.parse_args()

    test_key_count = 10
    test_iterations = 50
    if args.endpoint_url:
        print(f"Getting each item from the table {test_iterations} times, "
              f"using the DAX client.")
        # Use a with statement so the DAX client closes the cluster after completion.
        with amazondax.AmazonDaxClient.resource(endpoint_url=args.endpoint_url) as dax:
            test_start, test_end = get_item_test(
                test_key_count, test_iterations, dyn_resource=dax)
    else:
        print(f"Getting each item from the table {test_iterations} times, "
              f"using the Boto3 client.")
        test_start, test_end = get_item_test(
            test_key_count, test_iterations)
    print(f"Total time: {test_end - test_start:.4f} sec. Average time: "
          f"{(test_end - test_start)/ test_iterations}.")

在表中查询 DAX 客户端和 Boto3 客户端的多次迭代，并报告每个客户端花费的时间。

import argparse
import time
import sys
import amazondax
import boto3
from boto3.dynamodb.conditions import Key


def query_test(partition_key, sort_keys, iterations, dyn_resource=None):
    """
    Queries the table a specified number of times. The time before the
    first iteration and the time after the last iteration are both captured
    and reported.

    :param partition_key: The partition key value to use in the query. The query
                          returns items that have partition keys equal to this value.
    :param sort_keys: The range of sort key values for the query. The query returns
                      items that have sort key values between these two values.
    :param iterations: The number of iterations to run.
    :param dyn_resource: Either a Boto3 or DAX resource.
    :return: The start and end times of the test.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table = dyn_resource.Table('TryDaxTable')
    key_condition_expression = \
        Key('partition_key').eq(partition_key) & \
        Key('sort_key').between(*sort_keys)

    start = time.perf_counter()
    for _ in range(iterations):
        table.query(KeyConditionExpression=key_condition_expression)
        print('.', end='')
        sys.stdout.flush()
    print()
    end = time.perf_counter()
    return start, end


if __name__ == '__main__':
    # pylint: disable=not-context-manager
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'endpoint_url', nargs='?',
        help="When specified, the DAX cluster endpoint. Otherwise, DAX is not used.")
    args = parser.parse_args()

    test_partition_key = 5
    test_sort_keys = (2, 9)
    test_iterations = 100
    if args.endpoint_url:
        print(f"Querying the table {test_iterations} times, using the DAX client.")
        # Use a with statement so the DAX client closes the cluster after completion.
        with amazondax.AmazonDaxClient.resource(endpoint_url=args.endpoint_url) as dax:
            test_start, test_end = query_test(
                test_partition_key, test_sort_keys, test_iterations, dyn_resource=dax)
    else:
        print(f"Querying the table {test_iterations} times, using the Boto3 client.")
        test_start, test_end = query_test(
            test_partition_key, test_sort_keys, test_iterations)

    print(f"Total time: {test_end - test_start:.4f} sec. Average time: "
          f"{(test_end - test_start)/test_iterations}.")

扫描表以查看 DAX 客户端和 Boto3 客户端的多次迭代，并报告每个客户端花费的时间。

import argparse
import time
import sys
import amazondax
import boto3


def scan_test(iterations, dyn_resource=None):
    """
    Scans the table a specified number of times. The time before the
    first iteration and the time after the last iteration are both captured
    and reported.

    :param iterations: The number of iterations to run.
    :param dyn_resource: Either a Boto3 or DAX resource.
    :return: The start and end times of the test.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table = dyn_resource.Table('TryDaxTable')
    start = time.perf_counter()
    for _ in range(iterations):
        table.scan()
        print('.', end='')
        sys.stdout.flush()
    print()
    end = time.perf_counter()
    return start, end


if __name__ == '__main__':
    # pylint: disable=not-context-manager
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'endpoint_url', nargs='?',
        help="When specified, the DAX cluster endpoint. Otherwise, DAX is not used.")
    args = parser.parse_args()

    test_iterations = 100
    if args.endpoint_url:
        print(f"Scanning the table {test_iterations} times, using the DAX client.")
        # Use a with statement so the DAX client closes the cluster after completion.
        with amazondax.AmazonDaxClient.resource(endpoint_url=args.endpoint_url) as dax:
            test_start, test_end = scan_test(test_iterations, dyn_resource=dax)
    else:
        print(f"Scanning the table {test_iterations} times, using the Boto3 client.")
        test_start, test_end = scan_test(test_iterations)
    print(f"Total time: {test_end - test_start:.4f} sec. Average time: "
          f"{(test_end - test_start)/test_iterations}.")

删除 表。

import boto3


def delete_dax_table(dyn_resource=None):
    """
    Deletes the demonstration table.

    :param dyn_resource: Either a Boto3 or DAX resource.
    """
    if dyn_resource is None:
        dyn_resource = boto3.resource('dynamodb')

    table = dyn_resource.Table('TryDaxTable')
    table.delete()

    print(f"Deleting {table.name}...")
    table.wait_until_not_exists()


if __name__ == '__main__':
    delete_dax_table()
    print("Table deleted!")