Ruby rbtrace ArgumentError: command is too long

(This code blow requires you to include rbtrace in your gems)

To make a stack dump of your running rubyprocess, you could use somthing like this:

my_pid=1234
bundle exec rbtrace -p $my_pid -e 'Thread.new{GC.start;require "objspace";io=File.open("/tmp/ruby-heap.dump", "w"); ObjectSpace.dump_all(output: io); io.close}'

Unfortunately on FreeBSD / Mac OS X this results in (ArgumentError: command is too long)

A workaround for this, is to simply put the code in ruby file, and just load it. For example:
/tmp/rbcode.rb. With the following content

Thread.new{GC.start;require "objspace";io=File.open("/tmp/ruby-heap.dump", "w"); ObjectSpace.dump_all(output: io); io.close}

Next you can use rbtrace lik this:

bundle exec rbtrace -p $my_pid -e 'load("/tmp/rbcode.rb")'

FreeBSD cleanup all iocage

Finally I converted my internal sever to Bastille as jail manager. (I was using iocage). (https://bastillebsd.org)
To completely remove all stuff from iocage, you can run the following command:

iocage clean -a

Then delete the package

pkg delete py38-iocage

Iocage thank you for managing my jails for many year!
(I'm still using you on several other servers)

Cron Job to clear Rails Cache

The rails file cache is something that keeps growing.
Here are some 'handy' snippets.

Delete all files older then 7 days. (replace -delete with -print to test it)

find ./tmp/cache/ -type f -mtime +7 -delete

Delete all empty folders. (mindepth prevents the deletion of the root folder)

find ./tmp/cache/ -type d -empty -delete -mindepth 1

The whenever.rb I use

job_type :command_in_path, "cd :path && :task :output"

every :day, at: "0:40" do
  command_in_path "find ./tmp/cache/ -type f -mtime +7 -delete"
end

every :day, at: "1:10" do
  command_in_path "find ./tmp/cache/ -type d -empty -delete -mindepth 1"
end

Spree Issues config.action_view.raise_on_missing_translations

I'm working on a Rails Spree 4.1 app.
I enabled raising exception on missing translations via the option config.action_view.raise_on_missing_translations in config/environment/development.rb.
It's nice to know I a tranlsation is missing.

This was working fine, until I included the spree_mollie_gateway.

I couldn't boot the rails application anymore. It constantly raised:

gems/i18n-1.8.3/lib/i18n.rb:373:in `handle_exception': translation missing: nl.spree.validation.must_be_int (I18n::MissingTranslationData)

The woraround I now use is this: (config/development.rb)
Just enable it after the GEM is loaded

# Raises error for missing translations.
  config.action_view.raise_on_missing_translations = false
  Rails.application.config.to_prepare do
    ActionView::Base.raise_on_missing_translations = true
  end

FreeBSD, MySQL out of swap space

My FreeBSD server is giving a lot of swap errors. Every day the daily reporting email was filled with kernel messages like these:

my.server.com kernel log messages:
+swap_pager_getswapspace(31): failed
+swap_pager_getswapspace(32): failed
 ... and many more ...

After figuring out which process was causing this, it seemed MySQL was to blame.
That was odd, because these are the number of mysqltuner is reporting about my configuration:

[--] Physical Memory     : 8.0G
[--] Max MySQL memory    : 845.4M

Max 850 MB

After a lot of googling, reading MySQL, it seemd the performance schema could be to blame. Because is is completely stored in memory.

Now for several days in a row, I don't have the swaperrors ☺️
To disable the MySQL permance schema place the following in /usr/local/etc/mysql/my.cnf

[mysqld]
performance_schema = 0

Btw. I'm not sure if I need the performance scheme ..

⚠️ Followup a few weeks later

Unfortunately this isn't the solution. MySQL is still running out of swap space. I simply don't get it, because the memory usage should be limited

Followup more weeks later ;-)

ZFS ARC is taking a lot of memory...
Somehow MySQL checks the 'free' space and decides by itself to use swap. So the ZFS ARC memory is never released and MySQL .

To solve it limit the zfs arc memory /boot/loader.conf

vfs.zfs.arc_max="4G"