Core Transactions

Overview

Xenon has built-in support for transactions. A transaction enables a client to perform multiple operations on multiple documents (of the same kind or of different kinds) in a single logical unit, which is isolated from other logical units, and succeed or fails atomically.

Implementation of core transactions is optimistic. One implication is that a client needs to check the result of a COMMIT request - the request might fail due to confloicts with other transactions.

Usage

Typical usage flow of transactions: *A Client creates a new transaction, by sending a POST to the transaction service

• The client associates one or more operations with the transaction, by setting the transactionId property on the operation
• The client sends the operations to their targets
• If one of the operation fails, the client aborts the transaction by constructing and sending an ABORT request to the transaction service. If all the operations succeed a client attempts to commit the transaction by constructing and sending a COMMIT request to the transaction service. The client checks whether commit request has succeeded or failed; if it failed, the client can use one of multiple techniques to cope with the failure, like re-trying (starting a new transaction...) or propagating the failure to its client.