> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/gridgain/gridgain-9/tuning-and-troubleshooting/high-availability.md).

# High Availability

Deploying GridGain 9 for high availability — keeping the cluster and its data available through node and zone failures.

High availability is about keeping a GridGain 9 cluster serving requests through node, rack, and data-center failures. It builds on the replication and consensus described in [Architecture](/docs/gridgain/gridgain-9/architecture.md) and is realized through how you size replicas, place data, and configure availability behavior.

The concepts live in the Architecture section; this section focuses on applying them to a deployment.

## Key Topics

* [High Availability Mode](/docs/gridgain/gridgain-9/architecture/replication-and-consistency/high-availability-mode.md) — the availability guarantees GridGain 9 offers and their trade-offs.
* [Cluster Fault Tolerance](/docs/gridgain/gridgain-9/architecture/cluster/cluster-fault-tolerance.md) — how the cluster tolerates node failures.
* [Data Consistency and Replication](/docs/gridgain/gridgain-9/architecture/replication-and-consistency/data-consistency-and-replication.md) — how replication underpins availability.
* [Distribution Zones](/docs/gridgain/gridgain-9/architecture/data-distribution/distribution-zones.md) — controlling replica counts and data placement.
* [Performance Tuning](/docs/gridgain/gridgain-9/tuning-and-troubleshooting/performance-tuning.md) — keeping a highly available cluster performant under load.