Step 1: Create a new ledger - Amazon Quantum Ledger Database (Amazon QLDB)

Step 1: Create a new ledger

Important

End of support notice: Existing customers will be able to use Amazon QLDB until end of support on 07/31/2025. For more details, see Migrate an Amazon QLDB Ledger to Amazon Aurora PostgreSQL.

In this step, you create a new Amazon QLDB ledger named vehicle-registration.

To create a new ledger

  1. Review the following file (Constants.ts), which contains constant values that are used by all of the other programs in this tutorial.

    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * Constant values used throughout this tutorial.
 */
export const LEDGER_NAME = "vehicle-registration";
export const LEDGER_NAME_WITH_TAGS = "tags";

export const DRIVERS_LICENSE_TABLE_NAME = "DriversLicense";
export const PERSON_TABLE_NAME = "Person";
export const VEHICLE_REGISTRATION_TABLE_NAME = "VehicleRegistration";
export const VEHICLE_TABLE_NAME = "Vehicle";

export const GOV_ID_INDEX_NAME = "GovId";
export const LICENSE_NUMBER_INDEX_NAME = "LicenseNumber";
export const LICENSE_PLATE_NUMBER_INDEX_NAME = "LicensePlateNumber";
export const PERSON_ID_INDEX_NAME = "PersonId";
export const VIN_INDEX_NAME = "VIN";

export const RETRY_LIMIT = 4;

export const JOURNAL_EXPORT_S3_BUCKET_NAME_PREFIX = "qldb-tutorial-journal-export";
export const USER_TABLES = "information_schema.user_tables";

  2. Use the following program (CreateLedger.ts) to create a ledger named vehicle-registration.

    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import { QLDB } from "aws-sdk";
import {
    CreateLedgerRequest,
    CreateLedgerResponse,
    DescribeLedgerRequest,
    DescribeLedgerResponse
} from "aws-sdk/clients/qldb";

import { LEDGER_NAME } from "./qldb/Constants";
import { error, log } from "./qldb/LogUtil";
import { sleep } from "./qldb/Util";

const LEDGER_CREATION_POLL_PERIOD_MS = 10000;
const ACTIVE_STATE = "ACTIVE";

/**
 * Create a new ledger with the specified name.
 * @param ledgerName Name of the ledger to be created.
 * @param qldbClient The QLDB control plane client to use.
 * @returns Promise which fulfills with a CreateLedgerResponse.
 */
export async function createLedger(ledgerName: string, qldbClient: QLDB): Promise<CreateLedgerResponse> {
    log(`Creating a ledger named: ${ledgerName}...`);
    const request: CreateLedgerRequest = {
        Name: ledgerName,
        PermissionsMode: "ALLOW_ALL"
    }
    const result: CreateLedgerResponse = await qldbClient.createLedger(request).promise();
    log(`Success. Ledger state: ${result.State}.`);
    return result;
}

/**
 * Wait for the newly created ledger to become active.
 * @param ledgerName Name of the ledger to be checked on.
 * @param qldbClient The QLDB control plane client to use.
 * @returns Promise which fulfills with a DescribeLedgerResponse.
 */
export async function waitForActive(ledgerName: string, qldbClient: QLDB): Promise<DescribeLedgerResponse> {
    log(`Waiting for ledger ${ledgerName} to become active...`);
    const request: DescribeLedgerRequest = {
        Name: ledgerName
    }
    while (true) {
        const result: DescribeLedgerResponse = await qldbClient.describeLedger(request).promise();
        if (result.State === ACTIVE_STATE) {
            log("Success. Ledger is active and ready to be used.");
            return result;
        }
        log("The ledger is still creating. Please wait...");
        await sleep(LEDGER_CREATION_POLL_PERIOD_MS);
    }
}

/**
 * Create a ledger and wait for it to be active.
 * @returns Promise which fulfills with void.
 */
const main = async function(): Promise<void> {
    try {
        const qldbClient: QLDB = new QLDB();
        await createLedger(LEDGER_NAME, qldbClient);
        await waitForActive(LEDGER_NAME, qldbClient);
    } catch (e) {
        error(`Unable to create the ledger: ${e}`);
    }
}

if (require.main === module) {
    main();
}
    Note

    • In the createLedger call, you must specify a ledger name and a permissions mode. We recommend using the STANDARD permissions mode to maximize the security of your ledger data.

    • When you create a ledger, deletion protection is enabled by default. This is a feature in QLDB that prevents ledgers from being deleted by any user. You have the option of disabling deletion protection on ledger creation using the QLDB API or the AWS Command Line Interface (AWS CLI).

    • Optionally, you can also specify tags to attach to your ledger.

  3. To run the transpiled program, enter the following command.

    node dist/CreateLedger.js

To verify your connection to the new ledger, proceed to Step 2: Test connectivity to the ledger.