Skip to main content

Public API overview

QuorumKit has two sets of public headers. Both are installed with the library.

include/quorumkit/​

The primary API. New code should use these headers.

include/quorumkit/
  types.h          shared types: peer IDs, group IDs, error codes
  node.h           creating and operating a Raft node
  admin.h          administrative operations: add/remove peer, transfer leader
  discovery.h      peer discovery and route table
  storage.h        storage backend contracts
  util.h           small utilities
  extensions/
    filesystem.h   filesystem snapshot adaptor
    throttle.h     snapshot throttle

node.h is where most users start. It defines the node lifecycle: create, start, apply, snapshot, shut down. The other headers support it. storage.h is where the backend contracts live, including the requirement that backend families support dual write and bootstrap from any other backend family. See Storage backend contract, Canonical bootstrap image, and State equivalence and validation.

include/braft/​

The compatibility API. Existing braft code can keep using these headers -- they forward into the QuorumKit implementation underneath.

include/braft/
  raft.h                 core node, task, iterator, and state machine types
  node.h                 node declarations used by mock-based test code
  configuration.h        peer IDs and peer configuration
  snapshot.h             snapshot reader/writer surface used by applications
  storage.h              abstract snapshot interfaces used by tests
  util.h                 utilities such as AsyncClosureGuard
  errno.pb.h             Raft-specific error codes

Other braft headers may exist, but the precise compatibility promise lives in braft compatibility contract. Mixed-version rollout behavior is covered separately by wire compatibility contract and rolling migration contract.

How the two relate​

The braft headers depend on the QuorumKit headers, not the other way around. QuorumKit defines the model; the braft layer adapts to it.

For more on the design behind each surface, see Canonical public API, braft compatibility surface, braft compatibility contract, wire compatibility contract, and rolling migration contract.