Why does the Redis configuration not support custom db?

[gaye746560359]

DatabaseConfig

How to customize the default db to be db 1?

[cjdsellers]

Hi @gaye746560359

Thanks for the question.

Redis themselves discourage the use of multiple databases (SELECT), and it's not supported at all with Redis Cluster:

"When using Redis Cluster, the SELECT command cannot be used, since Redis Cluster only supports database zero. In the case of a Redis Cluster, having multiple databases would be useless and an unnecessary source of complexity."

The Redis creator (antirez) has also described multiple databases as one of his "worst design decisions in Redis" - they don't scale well and cause issues with active key expiry.

See: https://redis.io/docs/latest/commands/select/

NautilusTrader already namespaces all Redis keys using the trader ID and instance ID, which is the approach Redis recommends for separating data within a single instance. This means multiple NautilusTrader instances can safely share the same Redis db 0 without key collisions.

For separating unrelated applications, Redis recommends running separate Redis server instances rather than using different database numbers.

Given the above, we don't plan to add a db configuration option at this time.