Distributed
← Reliable asynchronous processing

Lesson 03.6

Reconciliation jobs

A reconciliation job compares a copy of data with its source of truth, finds records that have drifted, and repairs them.

Two lists that should match

The cookie shop's till 🧾 saves every sale. After each sale, a message updates the “sold today” board 📋 on the wall. The till is always right; the board is only as right as its messages.

Messages get lost, and computers glitch. How would anyone notice the board is wrong?

In this lesson you'll

  1. 1Watch the board drift away from the till.
  2. 2Guess what happens when Ben fixes the total.
  3. 3Find a way to fix the board that can't count twice.