8.1 Guidelines

Here are a few guidelines to develop custom applications that use the TCC transaction protocol.

In the TCC protocol, a transaction initiator services asks other participant microservices to reserve resources. When the initiator and all participants have acquired the required reservations, the initiator then sends a request to MicroTx to confirm all the reservations.

Based on its business logic, if the initiator service decides that it does not want or cannot use the reservations made, it requests the MicroTx to cancel all the reservations. What constitutes a reservation is completely up to the application.

The TCC transaction protocol relies on the basic HTTP verbs: POST, PUT, and DELETE. Ensure that your application conforms to the following guidelines:

• The transaction initiator service must use the POST HTTP method to create a new reservation. As a response to this request, the transaction participant services must return a URI representing the reservation. The MicroTx client libraries places the URI in MicroTx specific headers to ensure that the URI is propagated up the call stack.
• This protocol relies upon the participant services to ensure that all participant services either confirm their reservations or cancel their reservations. The URIs must respond to the PUT HTTP method to confirm a reservation, and to the DELETE HTTP method to cancel a reservation.