Introduction

This is basically my answer described to the problem in Screening_Task.pdf. It's not a production grade code as it was done in limited time.

Ingester

Basically starts the dispatcher and the handlers

Getting started

To start a server listening at port 9020 and requiring basic authentication run the following set of commands:

$ make build
$ ./ingester

You can the metrics and view the state of the internal components such as current values and errors

$ curl localhost:9020/metrics | jq .

Data can look as follows

{
  "cpu_usage_average_cpu": {
    "value": 0.49989037293819977
  },
  "cpu_usage_errors": {
    "count": 0
  },
  "cpu_usage_payload_processed_count": {
    "count": 55946
  },
  "dispatcher_errors": {
    "count": 0
  },
  "dispatcher_payload_processed_count": {
    "count": 168986
  },
  "last_kernel_upgrade_errors": {
    "count": 0
  },
  "last_kernel_upgrade_latest_time": {
    "value": 1613860787
  },
  "last_kernel_upgrade_payload_processed_count": {
    "count": 56357
  },
  "load_avg_errors": {
    "count": 0
  },
  "load_avg_maximum_load": {
    "value": 0.999986
  },
  "load_avg_minimum_load": {
    "value": 0.000020052788
  },
  "load_avg_payload_processed_count": {
    "count": 56683
  }
}

Architecture

Dispatchers and handlers run on different go routines but once the process is canceled in the main process the dispatchers and handlers are stopped

Dispatcher

Dispatcher calls the ingester and errors increase if it cannot marshal the data or receives server errors from the ingesters

Handlers

There are three handlers:

1. Cpu
2. Last Kernel Upgrade
3. Load Average

Handlers increase errors when the data in the payload is not what it expects