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Application Auto Scaling Client - AWS SDK for JavaScript v3

@aws-sdk/client-application-auto-scaling

NPM version NPM downloads

Description

AWS SDK for JavaScript ApplicationAutoScaling Client for Node.js, Browser and React Native.

With Application Auto Scaling, you can configure automatic scaling for the following resources:

  • Amazon AppStream 2.0 fleets

  • Amazon Aurora Replicas

  • Amazon Comprehend document classification and entity recognizer endpoints

  • Amazon DynamoDB tables and global secondary indexes throughput capacity

  • Amazon ECS services

  • Amazon ElastiCache for Redis clusters (replication groups)

  • Amazon EMR clusters

  • Amazon Keyspaces (for Apache Cassandra) tables

  • Lambda function provisioned concurrency

  • Amazon Managed Streaming for Apache Kafka broker storage

  • Amazon Neptune clusters

  • Amazon SageMaker endpoint variants

  • Spot Fleets (Amazon EC2)

  • Custom resources provided by your own applications or services

API Summary

The Application Auto Scaling service API includes three key sets of actions:

  • Register and manage scalable targets - Register Amazon Web Services or custom resources as scalable targets (a resource that Application Auto Scaling can scale), set minimum and maximum capacity limits, and retrieve information on existing scalable targets.

  • Configure and manage automatic scaling - Define scaling policies to dynamically scale your resources in response to CloudWatch alarms, schedule one-time or recurring scaling actions, and retrieve your recent scaling activity history.

  • Suspend and resume scaling - Temporarily suspend and later resume automatic scaling by calling the RegisterScalableTarget API action for any Application Auto Scaling scalable target. You can suspend and resume (individually or in combination) scale-out activities that are triggered by a scaling policy, scale-in activities that are triggered by a scaling policy, and scheduled scaling.

To learn more about Application Auto Scaling, including information about granting IAM users required permissions for Application Auto Scaling actions, see the Application Auto Scaling User Guide.

Installing

To install the this package, simply type add or install @aws-sdk/client-application-auto-scaling using your favorite package manager:

  • npm install @aws-sdk/client-application-auto-scaling
  • yarn add @aws-sdk/client-application-auto-scaling
  • pnpm add @aws-sdk/client-application-auto-scaling

Getting Started

Import

The AWS SDK is modulized by clients and commands. To send a request, you only need to import the ApplicationAutoScalingClient and the commands you need, for example DeleteScalingPolicyCommand:

// ES5 example
const {
  ApplicationAutoScalingClient,
  DeleteScalingPolicyCommand,
} = require("@aws-sdk/client-application-auto-scaling");
// ES6+ example
import { ApplicationAutoScalingClient, DeleteScalingPolicyCommand } from "@aws-sdk/client-application-auto-scaling";

Usage

To send a request, you:

  • Initiate client with configuration (e.g. credentials, region).
  • Initiate command with input parameters.
  • Call send operation on client with command object as input.
  • If you are using a custom http handler, you may call destroy() to close open connections.
// a client can be shared by different commands.
const client = new ApplicationAutoScalingClient({ region: "REGION" });

const params = {
  /** input parameters */
};
const command = new DeleteScalingPolicyCommand(params);

Async/await

We recommend using await operator to wait for the promise returned by send operation as follows:

// async/await.
try {
  const data = await client.send(command);
  // process data.
} catch (error) {
  // error handling.
} finally {
  // finally.
}

Async-await is clean, concise, intuitive, easy to debug and has better error handling as compared to using Promise chains or callbacks.

Promises

You can also use Promise chaining to execute send operation.

client.send(command).then(
  (data) => {
    // process data.
  },
  (error) => {
    // error handling.
  }
);

Promises can also be called using .catch() and .finally() as follows:

client
  .send(command)
  .then((data) => {
    // process data.
  })
  .catch((error) => {
    // error handling.
  })
  .finally(() => {
    // finally.
  });

Callbacks

We do not recommend using callbacks because of callback hell, but they are supported by the send operation.

// callbacks.
client.send(command, (err, data) => {
  // process err and data.
});

v2 compatible style

The client can also send requests using v2 compatible style. However, it results in a bigger bundle size and may be dropped in next major version. More details in the blog post on modular packages in AWS SDK for JavaScript

import * as AWS from "@aws-sdk/client-application-auto-scaling";
const client = new AWS.ApplicationAutoScaling({ region: "REGION" });

// async/await.
try {
  const data = await client.deleteScalingPolicy(params);
  // process data.
} catch (error) {
  // error handling.
}

// Promises.
client
  .deleteScalingPolicy(params)
  .then((data) => {
    // process data.
  })
  .catch((error) => {
    // error handling.
  });

// callbacks.
client.deleteScalingPolicy(params, (err, data) => {
  // process err and data.
});

Troubleshooting

When the service returns an exception, the error will include the exception information, as well as response metadata (e.g. request id).

try {
  const data = await client.send(command);
  // process data.
} catch (error) {
  const { requestId, cfId, extendedRequestId } = error.$$metadata;
  console.log({ requestId, cfId, extendedRequestId });
  /**
   * The keys within exceptions are also parsed.
   * You can access them by specifying exception names:
   * if (error.name === 'SomeServiceException') {
   *     const value = error.specialKeyInException;
   * }
   */
}

Getting Help

Please use these community resources for getting help. We use the GitHub issues for tracking bugs and feature requests, but have limited bandwidth to address them.

To test your universal JavaScript code in Node.js, browser and react-native environments, visit our code samples repo.

Contributing

This client code is generated automatically. Any modifications will be overwritten the next time the @aws-sdk/client-application-auto-scaling package is updated. To contribute to client you can check our generate clients scripts.

License

This SDK is distributed under the Apache License, Version 2.0, see LICENSE for more information.