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Runtime service is in charge of the workspaces execution depending on declared triggers, such as : events, dates or HTTP.

Technical stack

Library Role Version
Express HTTP framework 4.17.1
express-openapi-validator Swagger-based syntax validation of incoming requests 4.13.4 Message broker interface latest
moo Lexer for conditions parsing 0.5.1
nearly Parser for conditions 2.20.1


Events & API

Produced events :

  • runtime.webhooks.triggered
  • runtime.schedules.triggered
  • runtime.automations.executed
  • runtime.automations.scheduled


Performance & Scalability

Below are the results of differents performance tests conducted on this testing automation :

  name: performance testing automation
    endpoint: true
    - set:
        name: name
        value: Doe
        lifespan: "2"
    - conditions:
        "{{name}} == Doe":
          - emit:
              event: apps.test
                lastName: John
          - emit:
              event: apps.newtest
              lastName: Smith
    content: "{{name}}"
    requestBody: "{{body}}"
This automation is kept simple in order to avoid external interactions that might biase the results : a single set, a conditions block testing this variable and an emit.

During these tests, the runtime instances were connected to :
- A 2vCPU / 4GB MongoDB replicaset
- A 1vCPU / 1GB single-node redis

MongoDB primary node never exceeded 7% CPU and 30% Memory usage.
Redis never exceeded 5% CPU and 4% Memory usage.

See architecture schema

Testing script :

import http from 'k6/http';
import { check, group, sleep } from 'k6';

export const options = {
  stages: [
    { duration: '5m', target: 100 }, // simulate ramp-up of traffic from 1 to 100 users over 5 minutes.
    { duration: '10m', target: 100 }, // stay at 100 users for 10 minutes
    { duration: '5m', target: 0 }, // ramp-down to 0 users
  thresholds: {
    'http_req_duration': ['p(99)<1500'], // 99% of requests must complete below 1.5s
    'webhook run successfully': ['p(99)<1500'], // 99% of requests must complete below 1.5s

const BASE_URL = '';
const USERNAME = 'someAccountEmail';
const PASSWORD = 'someAccountPassword';
const WORKSPACE_ID= "someWorkspaceId"

export default () => {
  const webhookRes =`${BASE_URL}/v2/workspaces/${WORKSPACE_ID}/webhooks/Automation`, {
    foo: "too"

  check(webhookRes, {
    'webhook run successfully': (resp) => resp.status === 200,
    'is body present': (resp) => resp.json().hasOwnProperty('body'),


Scenario 1 : 100 concurrent users during 10 minutes, 1 runtime/events/api-gateway instance

The 100 concurrent users gradually reached their maximum number during the first 2 minutes, then stayed at that level during 5 minutes, before gradually decreasing during 2 minutes.


Scenario 2 : 100 concurrent users during 10 minutes, 2 runtime/events/api-gateway instances

The 100 concurrent users gradually reached their maximum number during the first 2 minutes, then stayed at that level during 5 minutes, before gradually decreasing during 2 minutes.


Limits & Constraints

Feature Limit type Value Action if exceeded Comments
Automation execution Number of successive automation execution for a same correlationId 20 The 21th event is ignored in order to stop the chain Configurable with MAXIMUM_SUCCESSIVE_CALLS env var
Contexts Memory space (in KB) used by all the contexts in one workspace 10 KB Once the limit reached, any set instruction is skipped until the admin frees memory with delete


Development standards and quality measurement

The required quality level corresponds to the recommended SonarQube Quality Gate:

  • 80% minimum code coverage
  • 3 % max of duplicated lines
  • Level A in Maintabily, Reliability and Security


Any action is logged into two different ways:

  • Trace of the HTTP call if there is one (produced at the Gateway API level)
  • Transcription of the action as an event (produced by the service handling the action)

In both cases, all the usual contextual information is included (provided by the common bootstrap between the backend services).\ As a minimum, this information should include : :

  • Correlation id
  • User id
  • Workspace id
  • Timestamp
  • Log criticality


Technical errors (aka unexpected errors) such as a timeout on a REST service call are caught by the service and logged with the full stack trace.

If this error occurs during the processing of an HTTP request, the caller simply receives a generic "Internal Error".

In addition to the error logs, the error is also transmitted as a generic error event.

Both in the log and in the event, the usual contextual information is included as much as possible (see Logs).


Just like the other backend micro services, this one provides different administration routes:

  • /metrics : Prometheus
  • /sys/logging : dynamically change log details
  • /sys/heapdump : Generate a memory dump that can be retrieved from the instance and loaded into Chrome for easy debugging
  • /sys/healthcheck : Returns a code 200 if the instance is "healthy"


Company Social Responsability (CSR)


The code should be formatted using Prettier, using the version specified in the package.json