Batch processes interacting with ROR data

Rails
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 M. 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.

–
Phlip
Redirecting... ← NOT a blog!!!

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!!”

–
Phlip
Redirecting... ← NOT a blog!!!

5

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

6

Dan M. 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

7

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.

Fred