batch processes interacting with ROR data

rubyonrails-talk
1

The application I am working on needs a nightly process to comb through the database and make periodic changes.

What is the best way to implement a script in order to leverage the existing database connection management and active record functionality?

Thanks.

2

Dan Munk wrote:

The application I am working on needs a nightly process to comb through the database and make periodic changes.

What is the best way to implement a script in order to leverage the existing database connection management and active record functionality?

Tell the OS to periodically run a script using 'cron', or the Task Manager, or some derivative therof. Some are called 'at'.

The script may run something like this:

   ruby script/runner "load('my_batch.rb')"

my_batch.rb then contains a batch of Ruby, enjoying the complete Rails context. IIRC.

There might be other ways to invoke the runner script. --help didn't confess them.

3

Thanks Phlip,

I have no problem with the scheduling of the script. I really want to understand how people are writing the scripts themselves share the existing database connections and use active record. For instance:

1. Periodic web service invocation. 2. External script.

Thanks, Dan

4

Fred wrote:

I think you're looking for difficulties where there are none. The script run by cron (for example) will have its own database connection, just as each of your mongrels/fcgi listeners has one, and can use ActiveRecord just as your controllers would or you would from script/console.

I solved that one, and re-used the connection. I did it the extra-sick way. I wrote a private action, available only in non-production mode, and then I hit it with a simulated web browser.

There's a less-sick way, right?

But all the pieces were just laying around, tempting me, saying "put me together like thiiiiis!!"

5

There are examples of how to use ActiveRecord outside of rails in the Rails Recipes book, it may be of use.

6

Dan Munk wrote:

Thanks Phlip,

I have no problem with the scheduling of the script. I really want to understand how people are writing the scripts themselves share the existing database connections and use active record. For instance:

1. Periodic web service invocation. 2. External script.

This is Rails - you don't share anything other than the database itself. Batch scripts and offload scripts run in their own separate process space unhindered by the Web facing application processes.

NeilW