Issues with mysql2 with and ruby - ruby

Question

Trying to get the gem mysql2 installed on ubuntu and I have tried all of the suggestions but I cannot get it to run. Here is the error in my application.
./bla.rb:65:in `post_init': undefined method `query' for nil:NilClass (NoMethodError)
from /var/lib/gems/1.8/gems/eventmachine-0.12.10/lib/em/timers.rb:51:in `call'
from /var/lib/gems/1.8/gems/eventmachine-0.12.10/lib/em/timers.rb:51:in `fire'
from /var/lib/gems/1.8/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `call'
from /var/lib/gems/1.8/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run_machine'
from /var/lib/gems/1.8/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run'
from ./bla.rb:234:in `start_server'
from ./bin/minibardaemon:15
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/application.rb:254:in `call'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/application.rb:254:in `start_proc'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/application.rb:263:in `call'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/application.rb:263:in `start_proc'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/application.rb:295:in `start'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/controller.rb:73:in `run'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons.rb:197:in `run_proc'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/cmdline.rb:109:in `call'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons/cmdline.rb:109:in `catch_exceptions'
from /var/lib/gems/1.8/gems/daemons-1.1.8/lib/daemons.rb:196:in `run_proc'
I have installed all of the packages that are recommended and installed mysql2 via gem but still no luck.
libmysqlclient-dev
Is installed.
Im on Ubuntu.
# gem -v
1.3.7
# ruby -v
ruby 1.8.7 (2010-08-16 patchlevel 302) [x86_64-linux]
Installing the gems
# gem install mysql
Building native extensions. This could take a while...
Successfully installed mysql-2.8.1
1 gem installed
Installing ri documentation for mysql-2.8.1...
Installing RDoc documentation for mysql-2.8.1...
# gem install mysql2
Building native extensions. This could take a while...
Successfully installed mysql2-0.3.11
1 gem installed
Installing ri documentation for mysql2-0.3.11...
Installing RDoc documentation for mysql2-0.3.11...
def create_mysql2
begin
mysql2 = Mysql2::EM::Client.new(
:username => DBUSER,
:password => DBPASS,
:host => DBHOST,
:port => DBPORT,
:socket => DBSOCKET,
:database => DBNAME
)
return mysql2
rescue Mysql2::Error => exception
$stderr.puts "Mysql Error: #{ exception.message }"
EventMachine::stop_event_loop
end
end
...
begin
mysql2 = create_mysql2
rescue Exception => ex
p ex
end
# query the db every x seconds.
EventMachine::add_periodic_timer(QUERY_INTERVAL) do
defer1 = mysql2.query "SELECT * FROM table LIMIT #{QUERY_LIMIT}"

Answer 1

doesn't realy look like mysql2 gem issue, could you please show 65'th line of you bla.rb file? And probably some number of lines that surround it.
it actually looks like your mysql2 client gets uninitialized for some reason.
I would advice to check if something like this works:
require 'mysql2'
mysql_client = Mysql2::Client.new(:host => "localhost", :username => "root")
mysql_client.query('sql .. ')
if so, there's clearly an issue in your script