Vlad Lazar 01399621d5 storcon: avoid promoting too many shards of the same tenant (#8099) ...

## Problem

The fill planner introduced in
https://github.com/neondatabase/neon/pull/8014 selects
tenant shards to promote strictly based on attached shard count load
(tenant shards on
nodes with the most attached shard counts are considered first). This
approach runs the
risk of migrating too many shards belonging to the same tenant on the
same primary node.

This is bad for availability and causes extra reconciles via the storage
controller's background
optimisations.

Also see
https://github.com/neondatabase/neon/pull/8014#discussion_r1642456241.

## Summary of changes
Refine the fill plan to avoid promoting too many shards belonging to the
same tenant on the same node.
We allow for `max(1, shard_count / node_count)` shards belonging to the
same tenant to be promoted.

2024-06-21 10:19:01 +01:00

..

migrations

Clean up 'attachment service' names to storage controller (#7326)

2024-04-05 16:18:00 +01:00

src

storcon: avoid promoting too many shards of the same tenant (#8099)

2024-06-21 10:19:01 +01:00

Cargo.toml

storcon: add drain and fill background operations for graceful cluster restarts (#8014)

2024-06-19 11:55:30 +01:00