til/mongodb/dump-and-restore-with-a-single-gzip-file.md

Dump And Restore With A Single gzip File

The mongodump and mongorestore utilities provide a way for grabbing all the data from one database and putting it into another database. These commands are useful for transitioning production data to a database instance with more computing resources.

The --archive and --gzip flags, supported by both commands, are what allow us to do the whole process with a single file. Without flags, mongodump will output multiple .bson files.

Here is what the mongodump command might look like pointed at a remote URI:

mongodump \
  --uri="mongodb+srv://<USER>:<PASSWORD>@<CLUSTER-HOST-URL>" \
  --archive="myapp-dump.20221105.gz" \
  --gzip

This will take a little while to run based on the size of the database. The result will be a file in your current directory with the name myapp-dump.20221105.gz. Because it is gzip'd, it will be a few times smaller than the standing database.

To then load all the data into your new Mongo database cluster, you'll use mongorestore with all the same flags, making sure to swap out the destination URI details with those of the new instance.

mongorestore \
  --uri="mongodb+srv://<USER>:<PASSWORD>@<NEW-CLUSTER-HOST-URL>" \
  --archive="myapp-dump.20221105.gz" \
  --gzip

For more details, see Output an Archive File and Compress the Output.