Support for RESP3 and Sharded Pub/Sub in Redis 7

[Rakeshya-Kore]

Redis 7 introduces significant enhancements to the Pub/Sub mechanism. Unlike Redis 6, where Pub/Sub messages were limited to a single shard, Redis 7 employs a sharded Pub/Sub mechanism. This improvement allows Redis to automatically determine which shard should handle the Pub/Sub traffic for a specific channel.

The sharded Pub/Sub mechanism provides the following benefits:

1. Load Distribution: It reduces the concentration of connections on a single shard by distributing Pub/Sub traffic across the cluster.
2. Scalability: This makes the Pub/Sub system more scalable by evenly balancing the workload among available shards.

To leverage the Sharded Pub/Sub feature in Redis 7, the RESP3 protocol is required. However, we have observed that the currently ioredis library does not support RESP3.

We would like to understand:

1. Are there any plans to add RESP3 protocol support in ioredis to enable Redis 7's advanced features like Sharded Pub/Sub?
2. If so, could you share any timelines or progress updates?