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sudo port -v selfupdate
sudo port install rbenv
sudo port install ruby-build
sudo port install readline

RUBY_CONFIGURE_OPTS="--with-readline-dir=/opt/local" rbenv install 2.7.1

# this gist previously also specified the openssl dir,
# but these days ruby-build downloads and builds its own openssl for you
# --with-openssl-dir=/opt/local

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In my previous post I described how to securely acquire the Mozilla list of root certificates and convert them to a form usable by curl and various libraries which don't ship with them.

Next, I want to point Net:HTTP at this file library-wide, so that it is used by all invocations of methods accessing https resources (in particular, Kernel#open, which in ruby 1.8.7 does not have a ca_file option and is therefore unusable with https). I hunted around the ruby standard library for a couple hours and came up with this:

require 'open-uri'
require 'net/https'

module Net
 class HTTP

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Active Record Connection Management in Rails 5.1 or lower

This guide is for Rails 5.1 or lower. Starting in 5.2, all these issues have been made irrelevant.

• rails/rails#31173
• rails/rails#31221
• rails/rails#31241
• rails/rails#28742
• rails/rails#29807

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# "foo" is not a placeholder, it's a name that needs to be given
# this exact command will work if a Dockerfile is present
docker build -t foo . && docker run -it foo

# if you want to force creation of an amd64 image when on an M1/arm64 Mac
docker build --platform linux/amd64 -t foo . && docker run -it foo

# if your container doesn't have a shell as an entrypoint
# e.g. node:@latest
docker build --platform linux/amd64 -t foo . && docker run -it --entrypoint bash foo

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example program being monitored - sleep.sh

while [ 1 ]
do
  sleep 1
  echo hello
done

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require 'socket'
Socket.tcp("example.com", 443, connect_timeout: 1).close

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raw = Rails.cache.redis.get( Rails.cache.redis.keys.first)
Marshal.load raw
Marshal.load(raw).instance_variable_get :@value
Zlib::Inflate.inflate Marshal.load(raw).instance_variable_get :@value



Marshal.load Zlib::Inflate.inflate Marshal.load(raw).instance_variable_get :@value

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sudo port unload postgresql12-server
sudo port load postgresql12-server

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sudo -u postgres pg_ctl -D /opt/local/var/db/postgresql12/defaultdb stop
sudo -u postgres pg_ctl -D /opt/local/var/db/postgresql12/defaultdb start

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background

There are many options available for tuning ruby memory management: https://github.com/ruby/ruby/blob/trunk/gc.c#L7420-L7444

The one that gets the most attention is RUBY_GC_HEAP_GROWTH_FACTOR, which is the only one Heroku suggests adjusting: https://devcenter.heroku.com/articles/ruby-memory-use#gc-tuning

I've often wondered what the drawback was for setting RUBY_GC_HEAP_GROWTH_FACTOR quite low for a webapp.