File Ownership

Before performing this analysis, you will want to have a active file to target

One interesting view of a file is who has been making changes to it. This can be particularly useful when there are questions about the file or changes to it that need to be reviewed. We can analyze the file ownership to determine who has made the most changes to a file.

Using an aggregation

We can analyze the file ownership with the following aggregation:

[
    { 
        $match: { 
            date: { $gt: ISODate("2020-01-01") },
            "files.filename": "src/mongo/db/repl/replication_coordinator_impl.cpp", 
        } 
    },
    {
        $sortByCount: "$author" 
    },
]

Using the command line

We can also use the file-ownership subcommand to perform this aggregation:

mdb-code-insights --config-file config.yml file-ownership --since "2020-01-01" --filename src/mongo/db/repl/replication_coordinator_impl.cpp

Owners of src/mongo/db/repl/replication_coordinator_impl.cpp: 309 total changes
William Schultz: 23 (7.44%)
Lingzhi Deng: 17 (5.50%)
Pavi Vetriselvan: 17 (5.50%)
A. Jesse Jiryu Davis: 16 (5.18%)
Jason Chan: 15 (4.85%)
Matthew Russotto: 15 (4.85%)
Vesselina Ratcheva: 14 (4.53%)
...

It looks like this file has had a good number of people make changes to it over the given time frame. It is good that there is some distributed knowledge about the file, but it could also be a sign that this file has too broad of responsibilities and might be a good target to refactor and split up.

What’s next

Now that you’ve looked at file ownership, try visualizing some data with MongoDB Charts.