Saturday afternoon at a shooting range thirty kilometers outside the city. Twenty customers on site, the next group already checking in at the kiosk. Then the LTE modem loses signal — a cell tower overloaded during a local event, or just the reality of operating in a place surrounded by concrete walls and forest. The cloud dashboard goes dark.
What happens to your bookings? Your inventory counts? The electronic locks securing the armory? If your scheduling system lives entirely in the cloud, the answer is: everything stops. Staff switch to paper, customers wait, and when the connection returns you spend the rest of the day reconciling handwritten notes with your database.
Why Cloud-Only Fails at Field Venues
Cloud-first architecture works brilliantly for offices, clinics, and urban co-working spaces — places with redundant fiber and stable Wi-Fi. But a growing category of businesses operates in environments where continuous internet is a luxury, not a given:
- Shooting ranges — often located in industrial zones or rural areas with poor cellular coverage, thick concrete walls blocking signal
- Paintball and airsoft fields — forest clearings, abandoned buildings, open terrain with no fixed broadband
- Offroad parks and rally stages — remote locations where the nearest fiber cable is kilometers away
- Bushcraft camps and survival events — deliberately off-grid, sometimes with satellite or mobile hotspot as the only link to civilization
These venues share a pattern: they need a booking system, inventory tracking, and access control just like any urban business — but they cannot guarantee uninterrupted connectivity. They work with sync windows — periods when the internet is available — rather than an always-on connection.
Island Mode: Your Location Becomes Self-Sufficient
Timerise solves this with Island Mode — a local server deployed on-site that maintains a complete replica of your location's data and automatically takes over when the cloud becomes unreachable.
The local server runs on a compact Linux machine (a mini PC, an Intel NUC, even a Raspberry Pi-class device with enough RAM) connected to the same LAN as your kiosk and staff terminals. It continuously replicates data from the cloud in the background. When the internet drops, terminals seamlessly switch to the local server. When connectivity returns, everything syncs back.
No manual intervention. No data loss. No downtime.
Architecture: Cloud, Local Server, and Terminals
Internet
|
+--------+--------+
| Cloud |
| Firestore SSOT |
+--------+--------+
|
DB-level replication
(real-time)
|
+--------+--------+
| Local Server |
| NestJS + RxDB |
+--------+--------+
|
LAN (Wi-Fi/ETH)
|
+-----------+-----------+
| | |
Kiosk Staff Hardware
(PWA) (PWA) (Lock Ctrl)Online mode: Terminals talk to the cloud API. The local server quietly replicates all data in the background — bookings, inventory, pricing, staff records, lock states — eight collections synchronized in real time.
Offline mode (Island Mode): When the cloud becomes unreachable, terminals redirect to the local server on the LAN. Bookings continue, inventory updates flow, electronic locks respond to commands. The location operates as an autonomous island.
Return to online: The local server detects connectivity restored, flushes all locally created data to the cloud, and terminals migrate back to the cloud API. The transition is invisible to staff and customers.
Heartbeat and Automatic Failover
The local server sends a heartbeat to the cloud every 30 seconds. If the cloud detects no heartbeat for over 60 seconds, it marks the location as offline. This status propagates in real time — the public booking page disables new reservations for that location (since the cloud can't guarantee slot availability while the location is in Island Mode), while on-site operations continue uninterrupted through the local server.
Database-Level Replication: Why It Matters
Most offline-capable systems attempt to solve sync at the application layer — queuing API calls, replaying REST requests, resolving conflicts through middleware. This approach is fragile. Every endpoint needs its own offline queue. Conflict resolution is ad-hoc. A failed replay can leave data in an inconsistent state.
Timerise takes a fundamentally different approach: replication happens at the database level.
The local server uses RxDB — a reactive database designed for real-time replication — synchronized directly with Firestore in the cloud. This is not an API cache. It is a full bidirectional database replica with built-in conflict resolution.
The advantages are significant:
- Speed — Data replicates as documents, not as serialized HTTP request-response cycles. There is no REST overhead, no retry queues, no middleware translation.
- Consistency — The database engine handles conflict resolution using timestamps and document revisions, not application code. Every record has a single source of truth.
- Security — Replication uses authenticated database channels with service account credentials, not exposed API endpoints. The attack surface is smaller than an API-based sync layer.
- Completeness — All eight data collections (locations, bookings, inventory, transactions, locks, lock logs, pricing, staff) replicate as a unit. There is no risk of partial sync where bookings update but inventory doesn't.
When the connection returns after an offline period, the local RxDB instance and cloud Firestore reconcile automatically. No manual merge. No lost records.
Kiosk and Staff Terminals
Island Mode powers two types of on-site terminals, both built as Progressive Web Apps (PWAs) that run in a browser:
Self-Service Kiosk
A touch-screen terminal where customers book and check in without staff assistance. The kiosk runs in fullscreen mode on a dedicated display — no address bar, no system UI, no distractions. It supports multiple languages, resets automatically after inactivity, and disables all browser escape routes (right-click, pinch-zoom, swipe navigation).
In Island Mode, the kiosk connects to the local server over LAN and continues to show available slots, accept bookings, and process check-ins. Customers never know the internet is down.
Staff Terminal
A PWA for employees to manage daily operations: view today's bookings, check in customers, issue and return inventory items (weapons, ammunition, safety equipment), control electronic locks, and adjust stock levels. Staff authenticate with their credentials — in online mode verified by the cloud, in offline mode verified against the local staff replica.
The staff terminal handles the operational core of a location: bookings, inventory, and physical access control — all three continue working in Island Mode.
Use Cases: Where Island Mode Shines
Shooting Ranges
The original use case. Shooting ranges combine several offline-hostile factors: thick concrete construction (signal attenuation), rural locations (poor coverage), and high-stakes inventory (weapons and ammunition that must be tracked precisely). Island Mode keeps the booking flow, inventory ledger, and electronic armory locks operational regardless of connectivity. When the internet returns — whether in minutes or at the end of the day — all data syncs to the cloud.
Paintball and Airsoft Fields
Typically located in forests, abandoned industrial sites, or open fields. Infrastructure is minimal. Internet often comes from a mobile hotspot that loses signal when the weather changes or too many phones connect. With Island Mode, the check-in kiosk at the entrance keeps processing groups, staff track equipment issue and return, and the operation runs smoothly through the sync window — morning setup with internet, offline during peak hours, evening sync when staff return to the office area.
Offroad Parks and Rally Events
Temporary or semi-permanent venues in remote terrain. Connectivity might be satellite-based with high latency and limited bandwidth, or a mobile hotspot that works only from the hilltop near the entrance. Island Mode is designed for exactly this scenario: replicate everything during the connectivity window, operate autonomously during the event, sync results when the crew packs up and returns to coverage.
Bushcraft and Survival Events
Multi-day events in deliberately off-grid locations. Internet availability might be limited to a 30-minute satellite window each morning. Island Mode turns that window into a sync opportunity — the local server pushes all overnight bookings, equipment logs, and access records to the cloud, pulls any updates (new pricing, schedule changes), and then operates independently until the next window.
How Sync Works in Practice
The lifecycle of a typical day at a field venue with Island Mode:
-
Morning startup — The local server boots with the machine (automatic systemd service). It connects to the internet and begins replicating. Within seconds, all eight data collections are synchronized with the cloud.
-
Operations begin — Customers arrive. The kiosk and staff terminals connect through the cloud API while internet is available. The local server continues replicating in the background, maintaining a live mirror.
-
Internet drops — The heartbeat fails. After three consecutive missed heartbeats (configurable), the local server switches to offline mode. Terminals detect the change and redirect to the local server's LAN address. Operations continue without interruption.
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Island operations — New bookings are created locally. Inventory moves are recorded. Lock commands execute. All data is stored in the local RxDB instance with full consistency.
-
Internet returns — The local server detects connectivity, sends a heartbeat, and begins flushing locally created data to Firestore. The cloud marks the location as online. Terminals gradually migrate back to the cloud API. The public booking page re-enables.
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End of day — All data is consistent between local and cloud. The manager can review the day's operations from anywhere — every booking, every inventory transaction, every lock event is in the cloud, regardless of how many offline periods occurred.
Built for the Real World
Island Mode isn't a theoretical failsafe — it's a production feature designed for venues where offline operation is a daily reality, not an edge case. Database-level replication means the sync is fast, consistent, and secure. PWA terminals mean no native apps to install or update. Automatic failover means staff don't need to flip a switch or call IT.
If your venue operates where the internet doesn't, Timerise keeps running.
Ready to take your operations offline-proof? Get in touch to discuss Island Mode deployment for your venue, or explore Timerise to see the full platform.