## Problem
Currently we don't have a way to migrate tenants from one pageserver to
another without a risk of gap in availability.
## Summary of changes
This follows on from https://github.com/neondatabase/neon/pull/4919
Migrating tenants between pageservers is essential to operating a
service
at scale, in several contexts:
1. Responding to a pageserver node failure by migrating tenants to other
pageservers
2. Balancing load and capacity across pageservers, for example when a
user expands their
database and they need to migrate to a pageserver with more capacity.
3. Restarting pageservers for upgrades and maintenance
Currently, a tenant may migrated by attaching to a new node,
re-configuring endpoints to use the new node, and then later detaching
from the old node. This is safe once [generation
numbers](025-generation-numbers.md) are implemented, but does meet
our seamless/fast/efficient goals:
Co-authored-by: Christian Schwarz <christian@neon.tech>
