Hey, Bruno from Inngest here, great question! Due to how Redis Clustering works, each individual slot (or keyspace) is assigned to a single shard (primary/read replica group), so data remains available.
More specifically, in production we're running multiple cluster shards in a primary/read replica configuration with support for automatic failover. Individual nodes are distributed across multiple availability zones (AZs) to prevent issues in one data center from impacting the entire cluster.
In case of downtime or maintenance of the primary node, the respective read replica is automatically promoted to primary, and writes can be continued within a few seconds.
More specifically, in production we're running multiple cluster shards in a primary/read replica configuration with support for automatic failover. Individual nodes are distributed across multiple availability zones (AZs) to prevent issues in one data center from impacting the entire cluster.
In case of downtime or maintenance of the primary node, the respective read replica is automatically promoted to primary, and writes can be continued within a few seconds.
Hope this helps!