Question

I am fairly new to databases and have just figured out how to use MongoDB in python2.7 on Ubuntu 12.04. An application I’m writing uses multiple python modules (imported into a main module) that connect to the database. Basically, each module starts by opening a connection to the DB, a connection which is then used for various operations.

However, when the program exits, the main module is the only one that ‘knows’ about the exiting, and closes its connection to MongoDB. The other modules do not know this and have no chance of closing their connections. Since I have little experience with databases, I wonder if there are any problems leaving connections open when exiting.

Should I:

• Leave it like this?

• Instead open the connection before and close it after each operation?

• Change my application structure completely?

• Solve this in a different way?

Answer 1

You can use one pymongo connection across different modules. You can open it in a separate module and import it to other modules on demand. After program finished working, you are able to close it. This will be the best option.

About other questions:

1. You can leave like this (all connections will be closed when script finishes execution), but leaving something unclosed is a bad form.
2. You can open/close connection for each operation (but establishing connection is a time-expensive operation.
3. That what I’d advice you (see this answer’s first paragraph)
4. I think this point can be merged with 3.