README.md

@aws-sdk/client-application-discovery-service

Description

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

Amazon Web Services Application Discovery Service

Amazon Web Services Application Discovery Service helps you plan application migration projects. It automatically identifies servers, virtual machines (VMs), and network dependencies in your on-premises data centers. For more information, see the Amazon Web Services Application Discovery Service FAQ. Application Discovery Service offers three ways of performing discovery and collecting data about your on-premises servers:

• Agentless discovery is recommended for environments that use VMware vCenter Server. This mode doesn't require you to install an agent on each host. It does not work in non-VMware environments.

  • Agentless discovery gathers server information regardless of the operating systems, which minimizes the time required for initial on-premises infrastructure assessment.

  • Agentless discovery doesn't collect information about network dependencies, only agent-based discovery collects that information.

• Agent-based discovery collects a richer set of data than agentless discovery by using the Amazon Web Services Application Discovery Agent, which you install on one or more hosts in your data center.

  • The agent captures infrastructure and application information, including an inventory of running processes, system performance information, resource utilization, and network dependencies.

  • The information collected by agents is secured at rest and in transit to the Application Discovery Service database in the cloud.

• Amazon Web Services Partner Network (APN) solutions integrate with Application Discovery Service, enabling you to import details of your on-premises environment directly into Migration Hub without using the discovery connector or discovery agent.

  • Third-party application discovery tools can query Amazon Web Services Application Discovery Service, and they can write to the Application Discovery Service database using the public API.

  • In this way, you can import data into Migration Hub and view it, so that you can associate applications with servers and track migrations.

Recommendations

We recommend that you use agent-based discovery for non-VMware environments, and whenever you want to collect information about network dependencies. You can run agent-based and agentless discovery simultaneously. Use agentless discovery to complete the initial infrastructure assessment quickly, and then install agents on select hosts to collect additional information.

Working With This Guide

This API reference provides descriptions, syntax, and usage examples for each of the actions and data types for Application Discovery Service. The topic for each action shows the API request parameters and the response. Alternatively, you can use one of the Amazon Web Services SDKs to access an API that is tailored to the programming language or platform that you're using. For more information, see Amazon Web Services SDKs.

• Remember that you must set your Migration Hub home region before you call any of these APIs.

• You must make API calls for write actions (create, notify, associate, disassociate, import, or put) while in your home region, or a HomeRegionNotSetException error is returned.

• API calls for read actions (list, describe, stop, and delete) are permitted outside of your home region.

• Although it is unlikely, the Migration Hub home region could change. If you call APIs outside the home region, an InvalidInputException is returned.

• You must call GetHomeRegion to obtain the latest Migration Hub home region.

This guide is intended for use with the Amazon Web Services Application Discovery Service User Guide.

All data is handled according to the Amazon Web Services Privacy Policy. You can operate Application Discovery Service offline to inspect collected data before it is shared with the service.

Installing

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

• npm install @aws-sdk/client-application-discovery-service
• yarn add @aws-sdk/client-application-discovery-service
• pnpm add @aws-sdk/client-application-discovery-service

Getting Started

Import

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

// ES5 example
const {
  ApplicationDiscoveryServiceClient,
  AssociateConfigurationItemsToApplicationCommand,
} = require("@aws-sdk/client-application-discovery-service");

// ES6+ example
import {
  ApplicationDiscoveryServiceClient,
  AssociateConfigurationItemsToApplicationCommand,
} from "@aws-sdk/client-application-discovery-service";

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 ApplicationDiscoveryServiceClient({ region: "REGION" });

const params = {
  /** input parameters */
};
const command = new AssociateConfigurationItemsToApplicationCommand(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-discovery-service";
const client = new AWS.ApplicationDiscoveryService({ region: "REGION" });

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

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

// callbacks.
client.associateConfigurationItemsToApplication(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.

• Visit Developer Guide or API Reference.
• Check out the blog posts tagged with aws-sdk-js on AWS Developer Blog.
• Ask a question on StackOverflow and tag it with aws-sdk-js.
• Join the AWS JavaScript community on gitter.
• If it turns out that you may have found a bug, please open an issue.

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-discovery-service 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.