reactive_dag_dashboard

A graph status dashboard for reactive_dag: the DAG's structure, each cell's status, and the last drain's trace — as a Phoenix LiveView you mount inside your own router pipeline.

Answers the three questions a reactive DAG makes you ask at 2am:

• What is stale or failing? — per-cell status rollups, with a sample of failing keys.
• What did the last drain actually do? — the %Drain.Report{} as a waterfall: what was claimed, what changed, what triggered it, how long each step took.
• Why did this node recompute? — follow triggered_by back up the graph.

Where the logic lives

This package renders; it computes nothing itself.

reactive_dag
  └─ ReactiveDag.Insights          ← queries: plan structure, status, retained reports
                                      (no UI dependencies; useful without Phoenix)

reactive_dag_dashboard             ← this repo
  └─ router macro + LiveView + graph rendering

That split is deliberate. The read API needs library internals and is valuable to hosts with no Phoenix at all (a mix task, a JSON endpoint, an alert). Keeping it in the core library also keeps Phoenix and LiveView out of reactive_dag's dependency tree.

Installation

def deps do
  [
    {:reactive_dag, "~> 0.17"},
    {:reactive_dag_dashboard, "~> 0.1"}
  ]
end

Mount it in your router, inside whatever pipeline already authenticates your admins — this package ships no auth of its own, by design:

import ReactiveDagDashboard.Router

scope "/admin" do
  pipe_through [:browser, :require_admin]

  reactive_dag_dashboard "/reactive-dag",
    plan: {MyApp.Dag, :plan, []}      # how to build the %Plan{} to display
end

The dashboard needs to know which graph to show. :plan names an MFA returning a %ReactiveDag.Plan{} — usually the same call your drain uses.

Retaining the drain trace

Drain.run/2 returns a %Report{} and most callers discard it. To see the trace, configure a sink (the default keeps the last N in ETS):

config :reactive_dag, report_sink: ReactiveDag.Insights.Buffer

Without a sink the dashboard still renders structure and status — the trace panel simply reports that nothing has been retained.

Status

Early. See the tracking issue for scope and open questions. Nothing here is stable yet.

License

MIT