How to arrange synchronization of MongoDB and REDIS?

Question

MongoDB

So, we have a NodeJS + Nginx webserver, and a redis database that pulls data from MongoDB.
The task is this: to force redis to update the cache when changes are made to Mongo, the database is edited directly from another server.
I see the following options:
1. Transfer the database update through the web api. Then NodeJS will pull redis for updates.
2. Periodically force redis to be cached again.
3.Rewrite or customize the MongoDB event handler.
Who faced?
What decision was made and how was it implemented?

Answer 1

Invalidate the radish cache as soon as you change the data in mongodb with a single request to the north, if you cannot predict how often the data will be updated, for example in a minute or a week. If you can, then approach #2, taking into account the average time to update records in the main database.