Again: Redis is a database, not just a cache - it doesn’t care if you store ephemeral cache artifacts or customer records within it. Redis doesn’t pose any constraints on the type of data. Inversely, you can use Postgres as a semi or fully consistent cache.
And yes, what you’re saying is technically correct, even a well-tuned single node doesn’t solve the availability problem: if it goes down, you have an outage. To avoid that, you need multiple instances to provide the same data, avoiding downtime if one of the nodes breaks eventually.
And yes, what you’re saying is technically correct, even a well-tuned single node doesn’t solve the availability problem: if it goes down, you have an outage. To avoid that, you need multiple instances to provide the same data, avoiding downtime if one of the nodes breaks eventually.