John Bachir jjb

Here's something I spent a long time debugging, so I'm making this gist to help others find the solution when searching.

Summary

postgres 12 on MacOS will cause crashes when forking. The solution is to do one of these two things:

add gssencmode: "disable" to database.yml
if using homebrew: uninstall postgres, update homebrew, reinstall postgres

Here's some discussion:

ged/ruby-pg#311

This recipe is a work in progress and has never been run as-is.

timeouts are in ms
lock timeout: in postgres, when a statement that wants a restrictive lock waits on another lock, other statements that want locks can't jump the queue. so even though the statement that is waiting might only take a very short amount of time, when it starts running, while it is waiting no other statements can begin. So we set the lock timeout pretty low and retry if we don't get it.
statement timeout: we set a short statement timeout before statements which do lock and which we expect to take a short amount of time, just in case something about our assumptions/understanding is wrong and the statement ends up taking a long time. if this happens the statement will bail early without causing harm, and we can investigate what is wrong with

Ruby doesn't let you inherit default behavior when writing a signal trap

Here's a beginning of an exploration of what default behavior is for each signal:

# https://github.com/ruby/ruby/blob/master/signal.c#L1331-L1358
reserved = %w[SEGV BUS ILL FPE VTALRM]
reserved += %w[KILL STOP] # not listed in code but reserved via some other mechanism i was too lazy to find

Signal.list.keys.each do |signal|

	lines = `find . -name '*.rb'`.split("\n")

	problems = []
	lines.each_slice(100) do \|slice\|
	threads = []
	slice.each do \|l\|
	threads << Thread.new do
	result = `ruby -c #{l}`
	if "Syntax OK" == result.strip
	print "."

	test results for https://github.com/puma/puma/pull/2228

	run 1 - nothing

	273.3 MB
	27.4 MB
	27.3 MB
	27.3 MB
	27.3 MB
	27.3 MB

	#!/usr/bin/ruby

	# save in ~/bin/dns and chmod 755

	unless ARGV[0]
	print `networksetup -getdnsservers Wi-Fi`
	exit
	end

	servers = case ARGV[0]

	ObjectSpace.each_object(File) do \|f\|
	unless f.closed?
	printf "%s: %d\n", f.path, f.fileno
	end
	end

	sudo port selfupdate
	sudo port install shared-mime-info
	sudo mkdir -p /usr/local/share/mime/packages/
	sudo ln -s /opt/local/share/mime/packages/freedesktop.org.xml /usr/local/share/mime/packages

	# minimal test to see if it's working - if it is, now include in Gemfile like normal
	gem install mimemagic -v '0.3.7' --source 'https://rubygems.org/'

	# "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