[londons_explore]

For anyone considering this, reconsider. It bit me many times.

In general, over time, load on some shards will increase while others decrease. Migrating a customer from one shard to another will likley cause a short outage for them, and many bugs down the line when they've bookmarked all kinds of things.

[brazzledazzle]

You need to preserve the name<->customer association and maintain another key that you can use to split traffic at the LB in case a customer outgrows their shard. But personally I think it looks hokey and should not be something a customer sees anywhere but perhaps a developer tool or sniffer.

[eonw]

could that not be resolved with a reverse proxy or load balancer trickery? ie; hide the shard name externally.