I’m currently working a client project using Laravel 4.2. The project uses 4 separate queues for a variety of tasks. Today I noticed that the queues were eating up an unhealthy amount of resources. After reading through the docs, I noticed that this CPU consumption was most likely being caused by spinning up the laraval framework for every job processed. By using the --daemon flag, introduced in 4.2, you can keep the framework loaded in memory and prevent unncessary work by bringing it up and down for each job. Awesome!

After switching to queue:work --daemon ... I noticed an immediate drop in CPU consumption! But, because I read the docs, I knew that I could expect the DB connections in the in-memory framework to cut out. I quickly refactored my jobs to call DB::reconnect(); prior to doing any database work. I pushed the change and went about my business.

A few hours later, I noticed my logs being flodded with exceptions coming from my job classes: MySQL server has gone away. Strange, those jobs should have been re-establishing their DB connection every time they were fired. After re-reading the docs, I realized that the in-memory framework didn’t have the change I previously pushed because I never restarted the daemon jobs… I tried to run php artisan queue:restart and was greeted with the following error:

  Command "queue:restart" is not defined.  
  Did you mean one of these?               

Huh? I was running Laravel 4.2, and the docs clearly said that this command should be available in 4.2. I started digging through the framework source, and sure enough, the command did not exist. I tried googling for solutions in vain, until I found a page for a package called Laravel 4 Down Safe. A line at the very bottom of the page caught my eye:

Requires Laravel v4.2.5, and uses the ./artisan queue:restart command to trigger a daemon worker restart.

Maybe the restart command was introduced in version 4.2.5? I checked my minor version, and sure enough I was using 4.2.0. I changed my laravel version in composer.json from "laravel/framework": "4.2" to "laravel/framework": "4.2.5" and ran a composer update. After that finished, I tried to run queue:restart and it worked! After restarting the daemons, they correctly re-established their database connections.

The moral of the story is that instead of using explicit minor versions, always grab the latest: "laravel/framework": "4.2.*". Also, RTFM.