sqs-rpc

A minimalist's implementation of a basic Remote Procedure Call (RPC) solution based on AWS SQS queues.

AWS SQS is a very simple managed queue service that is almost infinitely scalable. Using this RPC solution you can de-couple your NodeJS micro services and turn stateful REST apis into transient REST apis.

For information on SQS, look here.

usage

npm install --save @rootstream/sqs-rpc

Before you continue, you need to have a working SQS queue in your AWS account and have its URL ready. The queue URL looks something like this: https://sqs.<region>.amazonaws.com/<id>/<name>

You can either set the environment variable sqsrpc_config__endpoint to this URL or pass it in code.

The API is modeled after Socket.IO's ACKs.

const SqsRpc = require('@rootstream/sqs-rpc);

const machine1 = new SqsRpc();
machine1.start();
machine1.on('sample-method', async (arg1, arg2) => {
  return `hello from ${arg1} ${arg2}!`;
})

const machine2 = new SqsRpc();
machine2.start();
machine2.emit(machine1.id, 'sample-method', 'from', 'machine1').then(ret => {
  console.log(ret); // prints: "hello from machine1!"
})

API

new SqsRpc(options)

Constructor, creates a new instance of the RPC client.

options

• endpoint: SQS url to connect to
• timeout: timeout for all network operations over SQS (before RPC calls are considered expired - default: 10s)
• listeners: maximum number of RPC methods you are trying to register over SQS (default: 10)
• consumerOpts: options passed to the instance of sqs-consumer

start()

Starts accepting RPC jobs from the queue. This is an async method. You should await it. This is not reentrant!

emit(to, name, ...args)

Calls into a method named name on registered client with id to.

• to: ID of the remote machine. Can be obtained via .id property on a SqsUrl instance
• name: name of the remote RPC method
• ...args: any number of arguments passed to the remote method

This is an async method. You should await it. Result of the await is remote method's return value.

stop()

Stops accepting RPC jobs from the queue. This is an async method. You should await it. This is not reentrant!