CODEWITHSUNDEEP
ruby-on-railsrubyprocesscronrake
Ten Bitcomb
Ten Bitcomb

Reputation: 2374

Why does Rails console create so many Ruby processes?

I experimented with a Rake task with Cron. I started with no Ruby processes, then the Cron job started and spawned one process. The highlighted process below is what is run by Cron, which is expected:

enter image description here

I wanted to check if any records were being written to the database. I ran rails c to enter the Rails console, and noticed that suddenly four other ruby processes showed up in my process list as above. Why would this happen? I think that running the console should create one other process and not four.

After quitting the console, I am left with three Ruby processes including the Rake task that is running.

I am using Rails 4.2.

It's not that I find this to be problematic, but I am curious why there would need to be more than one process for a REPL and then two leftover processes after the REPL is closed.

Upvotes: 1

Views: 891

Answers (1)

Frederick Cheung
Frederick Cheung

Reputation: 84114

This is because of spring which has shipped with rails by default for a little while now.

You might notice that the second time you run rails c is a lot faster than the first time. This is because the first time you run a springified script your app is loaded as normal and then forks to run what you requested. The second time around this loader script can just fork a second time, so you get a much faster startup. This possible because of these extra processes you have noticed.

You can see them by running

spring status

And you can kill them by running

spring stop

Upvotes: 4

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