Rails freezes when varnish restarts during klarlack request

[grosser]

10000.times{ EsiHelper.purge_url '^xxxx$' } sudo /etc/i/varnish restart -> Rails instance freezes in 1/3 cases (normal error in 2/3 cases) i already tried removing the mutex + @conn.read + @conn.gets from cmd, but did not help so far

could you write a spec that tests this scenario or just try it out <-> maybe something wrong with our setup...

[grosser]

now we use this in lib/ext/klarlack_hack.rb (only works for non-threading rails...), only the thread will hang, which is not as bad as whole rails hanging...

@conn.write can freeze if varnish restarts

# Timeout does not help...
# so we do it asynchronous (Thread creation takes ~ 40ms)
Varnish::Client # require it ...
module Varnish::Client
  def cmd(name, *params)
    Thread.new do
      begin
        @conn.write "#{name} #{params.join(' ').gsub('\', '\\\')}\n"
        status, length = @conn.gets.split # <status> <content_length>\n
        content = @conn.read(length.to_i + 1) # +1 = \n
        content.chomp!
        raise Error, "Command #{name} returned with status #{status}: #{content}" if status.to_i != 200
          rescue Exception => e
        HoptoadNotifier.notify(e)
      end
    end
  end
end

[schoefmann]

Happy New Year and sorry for the delay.

Looks like a timeout issue to me (I assume you are using timeouts with SystemTimer?) I'll try to reproduce it. Maybe updating the socket code helps - the timeout stuff comes from memcache-client which has since improved it's own code futher. sigh - we could really need a proper socket lib that handles timeouts correctly...

[grosser]

i think the problem is that systemtimer does not get used on REE,

if !defined?(RUBY_ENGINE) require 'system_timer' SystemTimer

but REE has RUBY_ENGINE set to 'ruby', so a check like VERSION =~ 1.8 and not jruby should be better

ATM im using: if RUBY_VERSION =~ /^1\.8\./ and RUBY_PLATFORM !~ /java/

[schoefmann]

good catch. This might indeed fix it. I've changed the code accordingly and pushed the updated gem.

[grosser]

great, ill remove our monkeypatch and see if it works :)