Hello,
As far as I know, only Single Redis is supported for Kong OSS.
Redis Sentinel and Redis Cluster is available for Enterprise Edition. And In the Enterprise edition RateLimitAdvanced documentation, it is described that, fallback from redis policy to local policy will be done in case of some failure on Redis. Ref: Rate Limiting Advanced - Plugin | Kong Docs
Is this the same for RateLimit Plugin with single Redis?
Also, can single Redis (connected by multiple worker nodes) be a performance bottle neck when the requests count dramatically increase?