← All workshopsRead How Can Two Offline Teams Keep Both Inspection Counts?

NoSQL

Merge the disconnected teams’ inspection contributions

BOTIE

Connect both snapshots to Keep each replica’s largest component. Inspect the named components before calculating their total.
Ready to test
0 passed · 0 failed · 2 not run

An empty floor. Start with the information your machine needs.

Received result

Your answer will arrive here.

Examples, experiments and workspace controls
Live values

Connect a tool's inputs to see what it produces. You can try a branch before connecting it to Result.

Try your own inputs

Use a copy of the example to try your own data. Keep the problem's assumptions in mind, and predict the effect of a change before checking the output. You can also add another branch to compare two ways of doing the calculation.

Start at an output arrow, then click or drag to an input. Drag empty space to pan. Delete removes a selection. Ctrl/Cmd+Z undoes a change.
Context for this challenge

Connect both snapshots to Keep each replica’s largest component. Inspect the named components before calculating their total.

Each replica owns a grow-only inspection count and receives delayed snapshots of the others.

Inspect the component calculation
Keep each replica's largest component(
  First component map: First observed component map
  Second component map: Second observed component map
)
Examples and results
First observed component map
{
  "east": 3,
  "west": 1
}
Second observed component map
{
  "east": 2,
  "west": 4
}
Required result
{
  "east": 3,
  "west": 4
}
First observed component map
{
  "east": 3,
  "west": 4
}
Second observed component map
{
  "north": 2
}
Required result
{
  "east": 3,
  "north": 2,
  "west": 4
}
Try a fresh construction

This clears this draft, including its undo history. Earlier successful attempts stay recorded. Build again without opening hints to record an independent attempt.

Stuck? Inspect a worked construction

The tools below form one possible solution. You can assemble it, follow its signals, and undo that change to return to your own construction.

Assumptions and test precision

The toy state-based counter assumes unique owners, monotonic components and eventual exchange of valid states. It does not implement Redis or arbitrary document reconciliation. Numerical tests allow a difference of 0.001. Lists and structures must also have the right shape.

Your last tested pieces can start the full construction. An existing draft there keeps its own pieces.

One new writer and one old observation

This check uses the pieces from “Merge progress by component owner”.

BOTIE

The retained state is north five and south two. The incoming state is north four and west three. Predict the components and total after merging by owner.
First observed component map
{
  "north": 5,
  "south": 2
}
Second observed component map
{
  "north": 4,
  "west": 3
}

Use a number, text, or an array matching the requested result. For a matrix, put each row in brackets. Saving your prediction runs your current construction on these inputs and checks the earlier examples too.

Build a construction in the workspace above first. This case will test those pieces.

What breaks if a replica resets its component after a crash and keeps the same writer identity?

The maximum rule depends on monotonic owned components. Recovery must preserve or deliberately replace that identity contract.

The toy state-based counter assumes unique owners, monotonic components and eventual exchange of valid states. It does not implement Redis or arbitrary document reconciliation.

Work through the Python challenges →
Continue the courseWhy Does the Dashboard Still Count a Job That Was Closed? →
← Two Technicians Cannot Both Reserve the Last Kit