What is a replica set? (MongoDB 4.0.2)


I’ve been trying to under stand “replica set” for a long time. We are using MongoDB 4.0.2. We are not replicating anything. We have 1 MongoDB instance running.

But, when reading about transactions. It says " * In version 4.0 , MongoDB supports multi-document transactions on replica sets."

  • What does that mean?
  • Do you have a single replica set as default?
  • Do we need to create one?

Our system is now breaking and we need to solve this.


What does that mean?

EdIt: Documentation https://www.mongodb.com/docs/manual/core/transactions/#transactions-and-atomicity

You might wish to take the free online course MongoDB Database Administrator (DBA) which will explain things more clearly and completely than you are likely to get by Q&A here in the community forums. You can complete this course in a few hours if you dedicate an afternoon or two.

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This is the one that will really answer your questions:

M103: Basic Cluster Administration

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