AWS 環境からPlanetScale に接続した場合のレイテンシを計測してみた

import { APIGatewayEvent, APIGatewayProxyResult, Context } from "aws-lambda";
import * as mysql from "mysql2/promise";

const log = (param: Object) => {
  console.log(JSON.stringify(param));
};

let conn: mysql.Connection | undefined;

export const handler = async (
  event: APIGatewayEvent,
  context: Context
): Promise<APIGatewayProxyResult> => {
  let rows;

  try {
    let startTime = process.hrtime();

    conn = await mysql.createConnection(process.env.DATABASE_URL!);
    const connEnd = process.hrtime(startTime);

    startTime = process.hrtime();
    [rows] = await conn?.query("SELECT * FROM `posts`");
    const queryEnd = process.hrtime(startTime);

    log({
      kind: "connect",
      type: process.env.ANNOTATE,
      conn: connEnd[1],
      query: queryEnd[1],
    });
  } catch (e) {
    console.log(e);
  } finally {
    conn?.end();
  }

  return {
    statusCode: 200,
    body: JSON.stringify(rows),
  };
};

import * as cdk from "aws-cdk-lib";
import { Construct } from "constructs";

export class PlanetscaleLambdaStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    const databaseUrl = cdk.aws_ssm.StringParameter.valueForStringParameter(
      this,
      "planetScaleLambda-DatabaseURL"
    );

    const func = new cdk.aws_lambda_nodejs.NodejsFunction(this, "apiFn", {
      runtime: cdk.aws_lambda.Runtime.NODEJS_18_X,
      entry: "lambda/handler.ts",
      environment: {
        DATABASE_URL: databaseUrl,
        ANNOTATE: "planet-mysql",
      },
      tracing: cdk.aws_lambda.Tracing.ACTIVE,
      architecture: cdk.aws_lambda.Architecture.ARM_64,
    });

    const api = new cdk.aws_apigateway.RestApi(this, "apigw", {
      restApiName: "PlanetScale Lambda",
      description: "APIGW for PlanetScale and Lambda",
      deployOptions: {
        tracingEnabled: true,
      },
    });

    const integration = new cdk.aws_apigateway.LambdaIntegration(func, {
      requestTemplates: { "application/json": '{"statusCode": 200}' },
    });

    api.root.addMethod("GET", integration);
  }
}

import * as cdk from "aws-cdk-lib";
import { Construct } from "constructs";

export class RdsLambdaStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    const vpc = new cdk.aws_ec2.Vpc(this, "vpc", {
      maxAzs: 2,
      natGateways: 0,
      subnetConfiguration: [
        {
          cidrMask: 24,
          name: "Public",
          subnetType: cdk.aws_ec2.SubnetType.PUBLIC,
        },
      ],
    });

    const lambdaSg = new cdk.aws_ec2.SecurityGroup(this, "lambdaSg", {
      vpc,
      description: "",
      allowAllOutbound: true,
    });

    const dbSg = new cdk.aws_ec2.SecurityGroup(this, "dbSg", {
      vpc,
      allowAllOutbound: true,
    });
    const bastionSg = new cdk.aws_ec2.SecurityGroup(this, "bastionSg", { vpc });

    dbSg.addIngressRule(lambdaSg, cdk.aws_ec2.Port.tcp(3306));
    dbSg.addIngressRule(bastionSg, cdk.aws_ec2.Port.tcp(3306));

    const bastion = new cdk.aws_ec2.BastionHostLinux(this, "Bastion", {
      vpc,
      instanceType: cdk.aws_ec2.InstanceType.of(
        cdk.aws_ec2.InstanceClass.T4G,
        cdk.aws_ec2.InstanceSize.NANO
      ),
      securityGroup: bastionSg,
      subnetSelection: {
        subnetType: cdk.aws_ec2.SubnetType.PUBLIC,
      },
    });
    bastion.instance.addUserData("yum -y update", "yum install -y mysql jq");

    const dbUser = "user";
    const dbName = "test";

    const rdsCredentials = cdk.aws_rds.Credentials.fromPassword(
      dbUser,
      // WARN: 簡略化のためパスワードを文字列で指定してます
      new cdk.SecretValue("password")
    );

    const rds = new cdk.aws_rds.DatabaseInstance(this, "db", {
      vpc,
      engine: cdk.aws_rds.DatabaseInstanceEngine.mysql({
        version: cdk.aws_rds.MysqlEngineVersion.VER_8_0_31,
      }),
      credentials: rdsCredentials,
      databaseName: dbName,
      securityGroups: [dbSg],
      instanceType: cdk.aws_ec2.InstanceType.of(
        cdk.aws_ec2.InstanceClass.BURSTABLE4_GRAVITON,
        cdk.aws_ec2.InstanceSize.SMALL
      ),
      vpcSubnets: {
        subnetType: cdk.aws_ec2.SubnetType.PUBLIC,
      },
    });

    const databaseUrl = `mysql://${dbUser}:${rdsCredentials.password?.unsafeUnwrap()}@${
      rds.dbInstanceEndpointAddress
    }/${dbName}`;

    const func = new cdk.aws_lambda_nodejs.NodejsFunction(this, "apiFn", {
      runtime: cdk.aws_lambda.Runtime.NODEJS_18_X,
      entry: "lambda/handler.ts",
      environment: {
        DATABASE_URL: databaseUrl,
        ANNOTATE: "rds-mysql",
      },
      tracing: cdk.aws_lambda.Tracing.ACTIVE,
      architecture: cdk.aws_lambda.Architecture.ARM_64,
      securityGroups: [lambdaSg],
      vpcSubnets: vpc.selectSubnets({
        subnetType: cdk.aws_ec2.SubnetType.PUBLIC,
      }),
      vpc,
      allowPublicSubnet: true,
    });

    const api = new cdk.aws_apigateway.RestApi(this, "apigw", {
      restApiName: "RDS Lambda",
      description: "APIGW for RDS and Lambda",
      deployOptions: {
        tracingEnabled: true,
      },
    });

    const integration = new cdk.aws_apigateway.LambdaIntegration(func, {
      requestTemplates: { "application/json": '{"statusCode": 200}' },
    });

    api.root.addMethod("GET", integration);
  }
}

※ 簡略化のため、パスワードを文字列で指定し、インスタンスをパブリックサブネットに置いてますが実際に運用するときはセキュリティ的な考慮が必要です