jjb

# in default config, ActionMailer will use sidekiq wrapped in ActiveJob
# This makes it so there is no obvious/direct place to specify configuration
# It's easy to do with the below method, which can be placed in an initializer

Rails.application.config.after_initialize do
  ActionMailer::MailDeliveryJob.class_eval do
    sidekiq_options retry: 2
  end
end

jjb

require 'benchmark/ips'
require "benchmark/memory"

Benchmark.ips do |x|
  x.report("rand") do
    rand
  end

  x.report("rand(100)") do
    rand(100)

jjb

#!/usr/bin/env sh

# usage
# shipyard-shell PRNUMBER SERVICENAME
# shipyard-shell 6187 postgres
# shipyard-shell 6187 api

pr=$1
service=$2
identifier=`shipyard get environments | grep pr$pr | xargs | cut -w -f1` # xargs to remove leading and trailing whitespace

jjb

If you are in a situation where rubocop is hanging on a file but you don't know which one, afaik there is no way to have rubocop pring each filename as it runs it. None of the formatters do this and there is no verbose mode. Even --debug does not do this.

Here is a hack to (very slowly) invoke rubocop once for each candidate file:

bundle exec rubocop --list-target-files > files.txt
cat files.txt | xargs -L1 -n1 bundle exec rubocop # this works on macos/bsd, use --verbose instead of -t on linux

jjb

apt update
apt install -y apt-file
apt-file update

apt-file find psql
apt-file find bin/psql
apt-file find postgresql.conf
apt-file find --fixed-string convert # equivalent of .*convert.*, way too much
apt-file find --fixed-string /usr/bin/convert # need to know exact path
apt-file find --regexp '.*bin/convert$' # bingo. would also pick up .../sbin/

jjb

old=`pbpaste`
`echo '#{ENV['THE_TEXT']}' | pbcopy`
3.downto(0) do |second|
  `osascript -e 'display notification "Reseting clipboard in #{second} seconds" with title "TMP Clipboard"'`
  sleep 1
end
`echo '#{old}' | pbcopy`

jjb

For years, people have been using jemalloc with ruby. There are various benchmarks and discussions. Legend had it that Jemalloc 5 doesn't work as well as Jemalloc 3.

Then, one day, hope appeared on the horizon. Someone offered a config for Jemalloc 5.

The recipe would be something like this (shown with official docker ruby image).

FROM ruby:3.1.2-bullseye

jjb

invoke with bin/jemalloc rails s

We weren’t using 3 before, but have been running 5 in prod for ~10 months now, we saw ~25% less memory usage compared to default malloc

see also https://gist.github.com/jjb/9ff0d3f622c8bbe904fe7a82e35152fc

jjb

1. hello
2. hello
   1. nested
   2. nested
      1. more
      2. more
         1. and again

            puts "hello"

jjb

• runner does not use executor in <7, does use it in >=7
• console does not use executor in <7, not sure about >=7