A shard is a federated cluster of registry nodes responsible for a contiguous slice of the registry namespace. Sharding is by topological affinity — entries cluster with their likely consumers, not by geography.
What a shard stores
- Full entry payloads (all versions).
- Attestations attached to entries in this shard.
- Bond receipts for this shard's entries.
- Federation queues for outbound replication.
- A negative cache of recent misses.
Replication
Each entry has:
- 1 primary shard (the shard that owns the namespace).
- N shadow shards (replicas in other regions for redundancy).
- M edge caches (CDN-style, optional).
The primary is authoritative for writes; shadows handle read load.
Capacity
A shard targets ~10M entries. Beyond that threshold, the shard splits (see Topology). Splits are online and progressive — resolution remains uninterrupted throughout.