benweint

#!/usr/bin/env ruby

# Ruby Logger multi-process concurrency test.
# In an attempt to answer my own question at:
# http://stackoverflow.com/questions/13908745/can-rubys-stdlib-logger-class-safely-handle-writers-from-multiple-proceses
#
# Every line in each log file should begin with 'W,', and this string should
# appear in no other places in each line. To check results:
#
#   grep -l '.W,' *.log

benweint

def start_command(queue, pid)
  "cd #{current_path} && RAILS_ENV=#{rails_env} QUEUE=\"#{queue}\" \
   PIDFILE=#{pid} BACKGROUND=yes VERBOSE=1 NEWRELIC_DISPATCHER=resque INTERVAL=#{interval} \
   #{fetch(:bundle_cmd, "bundle")} exec rake resque:work"
end

benweint

#!/usr/bin/env ruby

text = "</script></head>\n"
outpath = 'text.txt'

File.open(outpath, 'w') { |f| f.write(text) }
text_read = File.read(outpath)

puts "text == text_read          => #{(text == text_read).inspect}"
puts "text.index('</head>')      => #{text.index('</head>')}"

benweint

#!/usr/bin/env ruby

text = "</</h"
outpath = 'text.txt'

File.open(outpath, 'w') { |f| f.write(text) }
text_read = File.read(outpath)

puts "text == text_read          => #{(text == text_read).inspect}"
puts "text.index('</h')      => #{text.index('</h')}"

benweint

# Here's the script I'll use to demonstrate - it just loops forever:

$ cat test.rb 
#!/usr/bin/env ruby

loop do
  sleep 1
end

# Now, I'll start the script in the background, and redirect stdout and stderr

benweint

#!/usr/bin/env ruby

# encoding: utf-8
# This file is distributed under New Relic's license terms.
# See https://github.com/newrelic/rpm/blob/master/LICENSE for complete details.

require 'tempfile'
require 'rbconfig'

def fail(msg, opts={})

benweint

#!/usr/bin/env ruby

require 'logger'

logger = Logger.new("/dev/null")

logger_thread = Thread.new do
  loop do
    logger.debug("hey" * 80)
    sleep 0.01

benweint

#!/usr/bin/env ruby

require 'logger'

logger = Logger.new("/dev/null")

logger_thread = Thread.new do
  loop do
    logger.debug("hey" * 80)
    sleep 0.01

benweint

#!/usr/bin/env ruby

Thread.new do
  loop do
    Thread.list.each do |t|
      puts "Got a nil backtrace for thread #{t}" if t.backtrace.nil?
    end
  end
end

benweint

# Redis memory dump tool
https://github.com/sripathikrishnan/redis-rdb-tools

# Generate dump csv 
rdb -c memory dump.rdb  >dump.csv

# Filter out unique IDs from Redis key names
time cat dump.csv | ruby -pe '$_.gsub! /:\d+:/, ":"' >keys.csv

# ... or in Perl