idempotent-operations

Idempotent Operations with Duplicate Detection via SWITCH

Retries in a distributed system can cause the same operation to execute twice. This workflow generates an idempotency key, checks if it has been seen before, then routes via SWITCH: new operations execute and record completion, while duplicates return the cached result.

Workflow

operationId, action, data
           |
           v
+-------------------+     +----------------------+
| io_generate_key   | --> | io_check_duplicate   |
+-------------------+     +----------------------+
  key generated               isDuplicate: false
           |
           v
      SWITCH on isDuplicate
      +--false (new)----------+--true (duplicate)--+
      | io_execute            | (return cached)    |
      | result: "success"     |                    |
      |       |               |                    |
      |       v               |                    |
      | io_record_completion  |                    |
      | recorded: true        |                    |
      +-----------------------+--------------------+

Workers

GenerateKeyWorker -- Generates an idempotency key from the operation inputs.

CheckDuplicateWorker -- Checks if the key has been seen. Returns isDuplicate: false for new operations.

ExecuteWorker -- Executes the action with the idempotency key. Returns result: "success".

RecordCompletionWorker -- Stores the completion record for the key. Returns recorded: true.

Tests

8 unit tests cover key generation, duplicate detection, execution, and completion recording.

Running

See ../../RUNNING.md for setup and execution instructions.