[Reliability] Jetstream events silently dropped under load

[daviddao]

Review Finding: 3d — MEDIUM

// jetstream/client.go:166
select {
case c.events <- event:
default:
    slog.Warn("Event channel full, dropping event")
}

Events are silently dropped when the channel buffer is full. For an AppView indexer, this means data loss — records that should be indexed are permanently missed.

Fix

Add backpressure: either block (risking WebSocket disconnect), use a growing buffer with limits, or implement a replay mechanism from cursor.

Files

• internal/jetstream/client.go (line 166)

From codebase review §3d