CompTIA A+ Core 1 (220-1201)Mobile DevicesHard
A user edits a contact's phone number on a laptop while offline. Before the laptop reconnects to the network, the user also edits the same contact's email address on a smartphone, and that change syncs to the cloud immediately. When the laptop finally reconnects and syncs, the user notices the phone number change is gone, though the email update is present. Which sync behavior best explains this outcome?
- AThe mobile hotspot's data cap was reached, halting the sync
- BThe Bluetooth pairing between devices timed out during the sync process
- CThe MDM geofencing policy blocked the laptop's location-based sync
- DThe sync service applied a "last write wins" conflict resolution, and the smartphone's later sync overwrote the offline laptop edit
Show answer & explanationAnswer & explanation
Correct answer: D. The sync service applied a "last write wins" conflict resolution, and the smartphone's later sync overwrote the offline laptop edit
Many sync services use a 'last write wins' conflict resolution model, where the most recently synced version of a record overwrites earlier changes to the same or related fields. Since the smartphone's edit reached the cloud first (laptop was offline), the laptop's later sync of the entire contact record could overwrite the phone number change with the outdated data it had cached before going offline.
Why the other options are wrong
- A. A hotspot data cap would prevent or delay sync entirely, not selectively overwrite one field.
- B. Bluetooth pairing is unrelated to cloud-based contact sync between a laptop and smartphone.
- C. Geofencing affects location-based access policies, not sync conflict resolution.
Sync Conflict Resolution (Last Write Wins)
A common cloud sync strategy where the most recently submitted change to a record overwrites earlier, unsynced changes made on another device.
- Offline edits can be lost if another device syncs a newer version first
- Common in contact, calendar, and file sync services
- Users should sync frequently to minimize conflicting offline edits
Memory trick: 'Last one to sync writes the story'