> ## Documentation Index
> Fetch the complete documentation index at: https://syteca.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Comparison of Standard and High Availability Modes

> The operational differences between a single-Application-Server deployment and High Availability mode with multiple Application Servers in a failover cluster.

<Warning>
  **NOT AVAILABLE IN SAAS.**
</Warning>

[High Availability mode](/docs/administration/deployment/high-availability) deploys Syteca with multiple Application Server instances on different nodes in a Microsoft failover cluster. This provides [load balancing](/docs/administration/deployment/load-balancing-installation) of data sent by Clients to optimize performance, and disaster-recovery protection — a backup Application Server keeps things running if one instance goes offline.

| Feature                      | Standard mode                                                                         | High Availability mode                                                     |
| ---------------------------- | ------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| Serial key types             | Permanent, Subscription, Trial, Not-for-Resale, SaaS, SaaS Trial, SaaS Not-for-Resale | Permanent, Subscription, Trial, Not-for-Resale                             |
| Database type                | MS SQL Server or PostgreSQL                                                           | MS SQL Server or PostgreSQL                                                |
| Application Server instances | One                                                                                   | Multiple                                                                   |
| System requirements          | Standard [system requirements](/docs/get-started/system-requirements)                      | Standard system requirements, plus a configured Microsoft failover cluster |
| Additional software          | None                                                                                  | Microsoft failover cluster                                                 |
| Component connection         | Physical IP address                                                                   | Logical IP address                                                         |
| Recommended for              | An average number of Client computers                                                 | A large number of Client computers                                         |

## Related

<CardGroup cols={2}>
  <Card title="High availability" icon="server" href="/docs/administration/deployment/high-availability">
    Full High Availability deployment guide.
  </Card>

  <Card title="Load Balancing installation" icon="network" href="/docs/administration/deployment/load-balancing-installation">
    Configure Syteca for a multi-Application-Server deployment.
  </Card>

  <Card title="Shared Storage High Availability" icon="database" href="/docs/administration/deployment/shared-storage-ha">
    An alternative HA deployment model using shared storage.
  </Card>

  <Card title="System requirements" icon="list-checks" href="/docs/get-started/system-requirements">
    Hardware and software requirements for both modes.
  </Card>
</CardGroup>