roachpb

pkg/roachpb/ defines the core CockroachDB wire-protocol types. It is one of the most widely imported packages in the tree.

What's in it

• data.proto — Value, Span, RangeDescriptor, ReplicaDescriptor, NodeDescriptor, StoreDescriptor, Lease, SpanConfig, Transaction, Intent, Lock, …
• metadata.proto — high-level identifiers (NodeID, StoreID, RangeID, TenantID).
• errors.proto — top-level Error envelope. The wire-encoded kvpb.Error references this.
• internal_raft.proto — small Raft-related shared types.
• mvcc.proto — types shared between MVCC and KV.
• tracing.proto — trace info wrapper.
• gossip.proto — gossip-keyed types.
• Hand-written Go: data.go and tenant.go carry helpers and methods on the proto-generated types.

Why it's its own package

roachpb predates the split between pkg/kv/kvpb/ (the actual BatchRequest/BatchResponse) and pkg/roachpb/ (the data types). Many older callers still reach for roachpb for descriptors and timestamps. New code should prefer the more specific package (kvpb for requests, roachpb for data types and identifiers).

Key types

Type	Used by
roachpb.Span	every layer; a [start, end) byte-key range
roachpb.Key	every layer; a single byte-key
roachpb.RangeDescriptor	KV server, range cache, gossip
roachpb.Lease	KV server, leases, raft
roachpb.Transaction	KV client and server
roachpb.SpanConfig	KV server, span-config reconciler
roachpb.Value	MVCC, KV, SQL
roachpb.NodeDescriptor	gossip, RPC dialer, allocator
roachpb.TenantID	every multi-tenant code path

Related pages

• Glossary — many of these terms are defined there.
• systems/kv — uses roachpb heavily.
• systems/spanconfig — SpanConfig is the reconciliation target.