Howto get public hostname from within a EC2 instance?

wget -q -O - http://169.254.169.254/latest/meta-data/public-hostname
=> ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com

Sidekiq is not faster than Resque

I changed my background job from Resque to Sidekiq, but i was suprise that, it was not currently faster anymore.

I found a possible problem: databse access: my jobs where accessing database.

i have 20 sidekiq worker.

I put  a pool_size for the database of 22 (1 web worker, 1 rake console, 20 workers .. in my yml) and also 22 database connections in mongD. It solved the problem. What takes before 1 hours take less than afterwards 10 minutes.

mongo.yml:

staging:

  adapter: mongodb

  database: database_name

  host: localhost

  port: 27017

  options:

    pool_size: 22

$ cat /etc/mongodb.conf |grep max

maxConns=1000

It may not be the more efficient settings, but I didn't have enougt time to tune them!

Requirement problems for Sidekiq

I wanted to use Sidekiq instead of Resque to handle my background jobs.

After normal changes I had lots of this kind of errors:

NoMethodError: undefined method `find' for #<User:0x00000003c8ea08>
NameError: uninitialized constant User

It was a requirement problem. I required everything with autoload, which is not thread-safe. - and deprecated-. I've changed for require.

Instead of
autoload :User, 'model/useer'
i use
require root_path + '/app/models/User.rb'

And no more error :)