Handle API gateway returning 503 with a response body of "busy"

[cer]

Sleep, loop and retry?

[cer]

The gateway will return a 503 with a Retry-Header: 1. The client should sleep and retry the request if it gets this response with the header.

[cer]

The NodeJS client will then behave the same way as the Java client: https://github.com/eventuate-clients/eventuate-client-java/blob/master/eventuate-client-java-http-stomp/src/main/java/io/eventuate/javaclient/restclient/EventuateRESTClient.java

[cer]

With the updated API gateway the error is now

{ ES Server Error: {"error":"busy"}
    at new EventuateServerError (/app/node_modules/@eventuateinc/eventuate-nodejs-client/dist/modules/EventuateServerError.js:23:11)
    at statusCodeError (/app/node_modules/@eventuateinc/eventuate-nodejs-client/dist/modules/EventuateClient.js:720:12)
    at /app/node_modules/@eventuateinc/eventuate-nodejs-client/dist/modules/EventuateClient.js:174:29
    at IncomingMessage.<anonymous> (/app/node_modules/@eventuateinc/eventuate-nodejs-client/dist/modules/EventuateClient.js:779:9)
    at emitNone (events.js:91:20)
    at IncomingMessage.emit (events.js:185:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:74:11)
    at process._tickDomainCallback (internal/process/next_tick.js:122:9)
  name: 'ES Server Error',
  timestamp: undefined,
  status: undefined,
  statusCode: 503,
  error: 'Server returned status code 503',
  exception: undefined,
  message: '{"error":"busy"}',
  path: undefined }