mmmries

# from https://github.com/Shopify/graphql-batch/blob/c84a5236ecb1c38fa275c76ee38017f30b7074be/examples/association_loader.rb
# This handles creating generic association loaders (see team_member_graph.rb for an example)
class AssociationLoader < GraphQL::Batch::Loader
  def self.validate(model, association_name)
    new(model, association_name)
    nil
  end

  def initialize(model, association_name)
    @model = model

mmmries

defmodule UserController do
  def create(params) do
    changeset = params
                |> cast([:name, :email])
                |> validate_required([:email])
                |> validate_other_stuff()
    WithSideEffects.create(changeset)
  end
end

mmmries

defmodule GOL do
  def encode(list) do
    encode(nil, list)
  end

  # Figure out the starting condition, whether we start "on" or "blank"
  def encode(nil, [1 | rest]), do:  encode({:on, 1, 1}, rest)
  def encode(nil, rest), do:  encode({:blank, 1}, rest)
  # If we have a sequence of "on" cells we need to know when it started and whether we are consecutive
  # with the last cell

mmmries

I wanted to run another round of performance benchmarks for gnat to see how it's request throughput has changed with the introduction of the ConsumerSupervisor which handles things like processing each request in its own supervised process.

I used a CPU-optimized digital ocean droplet with 16 cores, gnatsd 1.3.0, erlang 21.2.2 and elixir 1.8.0.rc0 You can read the setup instructions below for more details and the results_by_concurrency.md contains details about a lot of different runs.

I'm trying to measure the overhead in the system, so the requests are random byte strings that just get echoed back with processing. The measurements use byte strings of 4 bytes up to 1024 bytes.

TL/DR; You can do 170k+ synchronous requests/sec of small messages or 192MB+/sec of 1kb messages

mmmries

• Testing
  • mocking hardware
  • what is worth testing?
• Dev environment vs firmware
• Sensors:
  • Moisture Sensors
  • Temperator Sensors
  • Magnetic Sensors
• Touch Screen
• Carry the touch screen from device-to-device

mmmries

The main idea here is compose shared functionality into a pipeline of functions that all implement some shared behaviour.

defmodule Notification.Event do
  # The event (probably a bad name) is where you would put the structified JSON event you got from RabbitMQ
  defstruct [:sent_at, :user, :event]
end

defmodule Notification.Plug do
  @callback init(opts) :: opts

mmmries

mmmries

defmodule LatencyBenchmark do
  @default_settings %{
    num_actors: 1,
    actions_per_actor: 1,
  }

  def benchmark(action_fn, settings) do # = num_actors, actions_per_actor, setup_fn, action_fn) do
    settings = Map.merge(@default_settings, %{setup_fn: fn -> %{} end}) |> Map.merge(settings)
    settings = Map.put(settings, :action_fn, action_fn)
    {:ok, collector_pid} = Agent.start_link(fn -> [] end)

mmmries

Phoenix Nodes

First I created 3 droplets on digital ocean with 4-cores and 8GB of RAM. Login as root to each and run:

sysctl -w fs.file-max=12000500
sysctl -w fs.nr_open=20000500
ulimit -n 4000000
sysctl -w net.ipv4.tcp_mem='10000000 10000000 10000000'

mmmries

Protobuf Benchmarking

A really basic protobuf benchmark comparing the protobuf encoding/decoding performance. For details please see the benchmark.rb file in this gist and check the gpb benchmark files.

Latest Results

• protobuf-3.6.12
• gpb-3.26.6