Configuration

Relay uses functional options for wiring dependencies and a Config struct for tuning runtime behavior.

Functional options

The Relay struct is configured with functional options passed to relay.New():

r, err := relay.New(
    relay.WithStore(postgresStore),
    relay.WithLogger(slog.Default()),
    relay.WithConcurrency(20),
    relay.WithPollInterval(2 * time.Second),
    relay.WithBatchSize(100),
    relay.WithRequestTimeout(15 * time.Second),
    relay.WithMaxRetries(8),
    relay.WithRetrySchedule(customSchedule),
    relay.WithShutdownTimeout(60 * time.Second),
    relay.WithCacheTTL(time.Minute),
)

Available options

Option	Purpose	Default
`WithStore(s)`	Set the persistence backend (required)	--
`WithLogger(l)`	Set the structured logger	`slog.Default()`
`WithConcurrency(n)`	Number of delivery worker goroutines	`10`
`WithPollInterval(d)`	How often the engine checks for pending deliveries	`1s`
`WithBatchSize(n)`	Max deliveries dequeued per poll cycle	`50`
`WithRequestTimeout(d)`	HTTP timeout per delivery attempt	`30s`
`WithMaxRetries(n)`	Maximum delivery attempts before DLQ	`5`
`WithRetrySchedule(s)`	Backoff intervals between retries	`[5s, 30s, 2m, 15m, 2h]`
`WithShutdownTimeout(d)`	Max wait for in-flight deliveries on shutdown	`30s`
`WithCacheTTL(d)`	TTL for the catalog's in-memory cache (0 = no cache)	`30s`

Config struct

type Config struct {
    Concurrency     int
    PollInterval    time.Duration
    BatchSize       int
    RequestTimeout  time.Duration
    MaxRetries      int
    RetrySchedule   []time.Duration
    ShutdownTimeout time.Duration
    CacheTTL        time.Duration
}

Default retry schedule

var DefaultRetrySchedule = []time.Duration{
    5 * time.Second,
    30 * time.Second,
    2 * time.Minute,
    15 * time.Minute,
    2 * time.Hour,
}

After all retries are exhausted, the delivery moves to the DLQ.

Required options

The only required option is WithStore(). Without a store, relay.New() returns ErrNoStore.