What is core api and callback api?

Q: What is core api and callback api?

Start a transaction. Handle errors manually. Commit or abort the transaction explicitly. const session = client.startSession(); session.startTransaction(); try { // Perform operations using the session await db.collection("orders").insertOne({ item: "Laptop" }, { session }); await session.commitTransaction(); // Commit manually } catch (err) { await session.abortTransaction(); // Abort manually on error } finally { session.endSession(); } Reduces developer effort by automating retries and commit handling Recommended for most general use cases to simplify transaction workflows. Automatically incorporates error-handling logic for TransientTransactionError and UnknownTransactionCommmitResult. await client.withSession(async (session) => { session.startTransaction(); try { // Perform operations using the session await db.collection("orders").insertOne({ item: "Laptop" }, { session }); await session.commitTransaction(); // Handled automatically by the callback } catch (err) { await session.abortTransaction(); throw err; } });

Difficulty: 5/10

MongoDB driver APIs, async vs callback, API evolution

In MongoDB, the Core API and Callback API are approaches to handle transactions, enabling operations across multiple documents or collections as a single atomic unit. Here’s an explanation of both and their differences

Core API: The Core API is a lower-level interface for managing MongoDB transactions. It provides explicit control over the transaction lifecycle, requiring developers to:

1
Start a transaction.
2
Handle errors manually.
3
Commit or abort the transaction explicitly.

javascript

Callback API: The Callback API is a higher-level abstraction that simplifies transaction management. It automates aspects like retrying on transient errors and handling unknown commit results.

1
Reduces developer effort by automating retries and commit handling
2
Recommended for most general use cases to simplify transaction workflows.
3
Automatically incorporates error-handling logic for TransientTransactionError and UnknownTransactionCommmitResult.

javascript

Scenario Questions

0-2 years experience

2-5 years experience

1You have a legacy codebase that uses the callback API, but you need to add a new feature using async/await. How would you integrate the two styles without breaking existing functionality?

Follow-up Questions

Difficulty: 5/10

MongoDB driver APIs, async vs callback, API evolution

In MongoDB, the Core API and Callback API are approaches to handle transactions, enabling operations across multiple documents or collections as a single atomic unit. Here’s an explanation of both and their differences

Core API: The Core API is a lower-level interface for managing MongoDB transactions. It provides explicit control over the transaction lifecycle, requiring developers to:

1
Start a transaction.
2
Handle errors manually.
3
Commit or abort the transaction explicitly.

javascript

Callback API: The Callback API is a higher-level abstraction that simplifies transaction management. It automates aspects like retrying on transient errors and handling unknown commit results.

1
Reduces developer effort by automating retries and commit handling
2
Recommended for most general use cases to simplify transaction workflows.
3
Automatically incorporates error-handling logic for TransientTransactionError and UnknownTransactionCommmitResult.

javascript

Scenario Questions

0-2 years experience

2-5 years experience

1You have a legacy codebase that uses the callback API, but you need to add a new feature using async/await. How would you integrate the two styles without breaking existing functionality?