Sync Mechanics Deep Dive

Module Overview

Week 2 opens by revisiting two core SyncApp concepts — full vs partial sync and the batch syncer — with much greater technical depth than Week 1. You'll see real code walkthroughs of how the batch syncer compares hash codes, handles new/changed/unchanged records, and uses bucket-based storage. The module closes with on-prem debugging using RPC commands.

Why This Module Matters

These mechanics are what you'll debug most often. Understanding exactly how the batch syncer decides whether to send a record to Data Service — and knowing the RPC commands to inspect a running SyncApp — will cut your debugging time dramatically.

Learning Goals

• Explain full sync vs partial sync using the 'last sync time' configuration
• Describe the three batch manager types: Initial, Pending, and Standard
• Trace the sync record flow: extract → transform → hash → compare → selective send
• Understand bucket storage: entity ID mapped to hash code
• Use RPC commands to debug an on-prem SyncApp

Lessons