@openstatus/health-supabase

Postgres connection-pressure probe for Supabase for @openstatus/health, implementing the "Check Postgres connection pressure" health check from Supabase's Detecting issues guide.

supabase-js cannot run raw SQL, so the probe calls an RPC function you create once. Run this migration in the SQL editor:

create or replace function public.health_connection_pressure()
returns table (
  current_connections int,
  active_connections int,
  waiting_connections int,
  max_connections int,
  connection_percent numeric
)
language sql security definer set search_path = public as $$
  select
    count(*)::int,
    count(*) filter (where state = 'active')::int,
    count(*) filter (where wait_event_type is not null)::int,
    current_setting('max_connections')::int,
    round(100.0 * count(*) / nullif(current_setting('max_connections')::int, 0), 2)
  from pg_stat_activity;
$$;
revoke all on function public.health_connection_pressure() from public;
grant execute on function public.health_connection_pressure() to service_role;

pg_stat_activity needs security definer, and the function should only be granted to the role whose key the probe uses — service_role above, never anon or authenticated.

deno add jsr:@openstatus/health jsr:@openstatus/health-supabase
npm install @openstatus/health @openstatus/health-supabase

import { createClient } from "@supabase/supabase-js";
import { createHealthHandler } from "@openstatus/health";
import { supabaseProbe } from "@openstatus/health-supabase";

const client = createClient(env.SUPABASE_URL, env.SUPABASE_SERVICE_ROLE_KEY);

Deno.serve(
  createHealthHandler({ probes: [supabaseProbe({ client })] }),
);

The probe fails when the RPC returns an error, when the row shape is unexpected, or when connection_percent is above maxConnectionPercent (default 90). Non-critical by default, so pressure degrades the report instead of taking the service down. signal is forwarded via .abortSignal(signal) when the builder exposes it.

supabaseProbe({
  client,
  rpc: "health_connection_pressure",
  maxConnectionPercent: 80,
  name: "postgres",
  critical: true,
  skip: () => env.SUPABASE_NOOP === "true",
});

A threshold breach throws SupabaseConnectionPressureError, which carries the full row. Expose it through formatError:

import { SupabaseConnectionPressureError } from "@openstatus/health-supabase";

createHealthHandler({
  probes: [supabaseProbe({ client })],
  formatError: (error) =>
    error instanceof SupabaseConnectionPressureError
      ? `${error.message} (${error.row.current_connections}/${error.row.max_connections})`
      : error.message,
});

About openstatus

openstatus is the open-source uptime monitoring and status page platform. This package is part of @openstatus/health, the /health endpoints behind openstatus's own services, extracted so any JavaScript server can expose one. Point an openstatus monitor at the endpoint and assert on status in the body to be alerted on degraded before it becomes unhealthy.

Source: github.com/openstatusHQ/health. Issues and PRs welcome.

License

MIT