ACID Transactions in MongoDB

Implement a Bank Transfer Transaction

Write a MongoDB transaction that transfers money between two accounts, ensuring atomicity and consistency.

Expected output: Both accounts are updated atomically, or no changes are made if an error occurs.

Hint: Use a session and startTransaction(), update both accounts within the transaction, and commit or abort based on success.

Experiment with Transaction Isolation

Create two concurrent transactions that update the same document and observe the isolation behavior.

Expected output: One transaction commits successfully while the other retries or aborts due to conflicts.

Hint: Use sessions and transactions in parallel and check for write conflicts or retries.

ACID stands for Atomicity, Consistency, Isolation, and Durability. MongoDB transactions ensure these properties to maintain data integrity across multiple operations.

Multi-document transactions are supported starting from MongoDB version 4.0 for replica sets and 4.2 for sharded clusters.

You start a session with client.startSession(), then call session.startTransaction(), perform operations with the session, and finally call session.commitTransaction() to commit.