Triggering the Delayed Job crash when using New Relic ruby agent 3.5.5.38

Environment

• Mac OS X 10.7.5
• Postgresql 9.1.3
• Rails 3.2.11
• ruby1.9.3-p287 and p374
• bundler 1.2.1
• rake 10.0.3
• rvm 1.11.3.3

Setup

• Clone this repo
• bundle install --path vendor --binstubs
• cp config/newrelic.yml.example config/newrelic.yml and add your API key
• create a postgres database to match config/database.yml
• run the migrations: rake db:migrate

Trigger the Crash

Start up delayed job:

$ bundle exec script/delayed_job run
delayed_job: process with pid 89879 started.

In a separate prompt:

rake dj_test:send_test_email

After sending the email, delayed_job will crash with:

FATAL:  invalid frontend message type 1
PG::Error: connection not open
: UPDATE "delayed_jobs" SET locked_by = null, locked_at = null WHERE (locked_by = 'delayed_job host:xxxx.local pid:89879')