Documentation
¶
Overview ¶
Package ha registers writer/replica HA for a Base app.
Quasar consensus is leaderless — all nodes are equal validators. SQLite's single-writer constraint is satisfied by deterministic writer-pinning: the lowest-sorted alive NodeID holds the write lock. All others are replicas that 307 mutating requests to the writer.
app := base.New() ha.Register(app) app.Start()
Config lives under the BASE_* env namespace. See the base-ha README.
HA is a no-op unless BASE_LOCAL_TARGET or BASE_STATIC_WRITER is set.
Index ¶
- func Register(app core.App)
- type Heartbeat
- type QuasarConfig
- type QuasarWriter
- func (w *QuasarWriter) Close()
- func (w *QuasarWriter) HandleHeartbeat(rw http.ResponseWriter, r *http.Request)
- func (w *QuasarWriter) Ingest(h heartbeat)
- func (w *QuasarWriter) IsWriter() bool
- func (w *QuasarWriter) Ready() <-chan struct{}
- func (w *QuasarWriter) RedirectTarget() string
- func (w *QuasarWriter) SelfHeartbeat() Heartbeat
- type StaticWriter
- type WriterProvider
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Register ¶
Register wires HA into the given app.
Behavior depends on env:
- BASE_STATIC_WRITER=http://... → all writes forward to that URL.
- BASE_LOCAL_TARGET=http://... + BASE_PEERS=a,b → Quasar heartbeat writer-pin; lowest-sorted alive NodeID is the writer.
- Neither set → plugin is inactive (standalone Base).
The full go-ha CDC pipeline (change-set capture over NATS-compatible JetStream) is provisioned by the base-ha binary at the SQL driver level. This plugin handles the HTTP surface: write-forwarding middleware and the /_ha/heartbeat endpoint.
Types ¶
type QuasarConfig ¶ added in v0.40.5
type QuasarWriter ¶ added in v0.40.5
type QuasarWriter struct {
// contains filtered or unexported fields
}
QuasarWriter pins one node as the SQLite writer using Quasar-style deterministic ranking over a heartbeat-based alive set.
Quasar consensus is leaderless — all nodes are equal validators. But SQLite has a single-writer constraint, so we rank alive peers by NodeID and pin the lowest-sorted as the writer. All others are replicas that 307 mutating HTTP to the writer and apply change-sets via async replication.
Transport: HTTP /_ha/heartbeat by default. Compose with plugins/zap for sub-ms ZAP transport (the ZAP plugin provides mDNS discovery + binary messaging for the fast path).
O(peers) memory, O(1) per heartbeat.
func NewQuasarWriter ¶ added in v0.40.5
func NewQuasarWriter(cfg QuasarConfig) (*QuasarWriter, error)
func (*QuasarWriter) Close ¶ added in v0.40.5
func (w *QuasarWriter) Close()
func (*QuasarWriter) HandleHeartbeat ¶ added in v0.40.5
func (w *QuasarWriter) HandleHeartbeat(rw http.ResponseWriter, r *http.Request)
HandleHeartbeat is the HTTP handler for /_ha/heartbeat.
func (*QuasarWriter) Ingest ¶ added in v0.40.5
func (w *QuasarWriter) Ingest(h heartbeat)
Ingest processes an incoming heartbeat (from any transport — HTTP or ZAP). Exported so the ZAP plugin can feed heartbeats in from the binary path.
func (*QuasarWriter) IsWriter ¶ added in v0.40.5
func (w *QuasarWriter) IsWriter() bool
func (*QuasarWriter) Ready ¶ added in v0.40.5
func (w *QuasarWriter) Ready() <-chan struct{}
func (*QuasarWriter) RedirectTarget ¶ added in v0.40.5
func (w *QuasarWriter) RedirectTarget() string
func (*QuasarWriter) SelfHeartbeat ¶ added in v0.40.5
func (w *QuasarWriter) SelfHeartbeat() Heartbeat
SelfHeartbeat returns this node's identity for external transports.
type StaticWriter ¶ added in v0.40.5
type StaticWriter struct{ Target string }
StaticWriter always routes writes to a fixed URL.
func (*StaticWriter) IsWriter ¶ added in v0.40.5
func (s *StaticWriter) IsWriter() bool
func (*StaticWriter) RedirectTarget ¶ added in v0.40.5
func (s *StaticWriter) RedirectTarget() string
type WriterProvider ¶ added in v0.40.5
WriterProvider abstracts writer-pin strategies.
Source Files