High availability (HA) means your database stays reachable and consistent when individual components fail or during planned maintenance. For most applications the database is the hardest component to lose — when it is down, the product stops. What you get on SurrealDB Cloud depends on your plan and instance topology.
Start (single-node)
Start instances run SurrealDB on a single compute node with dedicated storage. This model is simple and cost-effective for development, staging, and workloads that tolerate brief downtime.
There is no multi-node failover within the instance — if the node, disk, or underlying host fails, connections drop until the platform recovers it.
Pausing an instance stops compute deliberately; resuming brings it back on the same configuration.
Protect production data with automated backups and tested restore procedures rather than assuming in-instance redundancy.
Self-hosting a single node is similarly easy to reason about; Start on Cloud adds managed patching, snapshots, and operations without you running the server. For workloads that must keep serving through hardware or zone failures, use Scale or architect retries and failover at the application layer.
Scale (multi-node on SurrealDS)
Scale clusters run multiple SurrealDB query nodes against SurrealDS distributed storage. HA is built into the architecture:
Multiple compute nodes — Scale starts at three compute units (three query nodes) and you can add more horizontally as throughput grows.
Survive node loss — SurrealDS coordinates replication and quorum consensus so the cluster keeps serving when one node is unavailable, instead of treating three separate single-node databases.
Compute can be resized or replaced — durable state lives in the storage tier, not on individual query nodes.
Many teams achieve basic HA with two replicated database nodes. Scale’s three-node minimum leaves headroom during failures, upgrades, and maintenance while one node is out of service.
Scale is the managed option when you need fault-tolerant production without operating your own Kubernetes cluster, storage replication, and upgrade runbooks. SurrealDB Cloud provisions the cluster, applies patches, manages backups, and coordinates rolling version upgrades — work that otherwise sits with platform or infrastructure teams on self-hosted deployments.
See Cloud architecture and Scaling.
Choosing between Start and Scale for HA
| Requirement | Start | Scale |
|---|---|---|
| Accept brief maintenance or node recovery windows | Suitable | Suitable |
| Survive node failure without manual failover | Limited | Built-in (multi-node + SurrealDS) |
| Horizontal query scale | Resize vertically only | Add compute nodes |
| Operate HA yourself (Kubernetes, replication, patching) | Self-host or accept single-node risk | Managed by Cloud |
Related topics
Instance management — pause, resume, and delete instances.
Backups & recovery — recover from logical mistakes or regional issues.
Patches & upgrades — change SurrealDB version with platform-managed rollouts.