[IGNITE-17839] Improve semantics of implicit txn management for async transactions

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-beta1
• Labels: ignite-3
• Release Note: New API for async implicit transactions: runInTransactionAsync
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Alexey Scherbakov
• Reporter: Alexey Scherbakov
• Reviewer: Alexander Lapin
• Created: 06/Oct/22 15:33
• Updated: 13/Oct/22 12:09
• Resolved: 12/Oct/22 16:12

Description

There is a usability issue for transaction implicit management API.

For async transaction tx.commit must be called after all async ops are enlisted to the transaction. This is a responsibility of a user in case of explicit management.

But, for implicit management, tx.commit must be called automatically. This is not generally not possible for async flows, because by the end of a closure some operations are not yet started.

The example:

runInTransactionAsync(tx ->

{ return opAsync().thenComposeAsync(res -> otherOpAsync()); }

)

We can fix this by introducing async context for implicit management and require a user to return last completion stage in the chain, like:

<T> CompletableFuture<T> runInTransactionAsync(Function<Transaction, CompletableFuture<T>> clo);

Issue Links

• links to: GitHub Pull Request #1183