Supabase Observability

Overview

Monitor Supabase projects end-to-end: Dashboard reports for API/database/auth metrics,

supabase inspect db

pg_stat_statements

Prerequisites

• Supabase CLI installed (

  npx supabase --version

  )
• Supabase project linked (

  supabase link --project-ref <ref>

  )
• Pro plan or higher for log drain support and extended log retention

• @supabase/supabase-js

  v2+ installed for application-level monitoring

Instructions

Step 1: Dashboard Reports and CLI Inspect Commands

Supabase Dashboard provides built-in reports under Dashboard > Reports:

For deeper Postgres diagnostics, use the CLI inspect commands:

# Table sizes — find the largest tables
npx supabase inspect db table-sizes --linked

# Index usage — find unused indexes wasting space
npx supabase inspect db index-usage --linked

# Cache hit ratio — should be > 99% (below 95% means upgrade compute)
npx supabase inspect db cache-hit --linked

# Sequential scans — tables needing indexes
npx supabase inspect db seq-scans --linked

# Long-running queries — find stuck queries
npx supabase inspect db long-running-queries --linked

# Table index sizes — compare index vs table size
npx supabase inspect db table-index-sizes --linked

# Bloat — estimate wasted space from dead tuples
npx supabase inspect db bloat --linked

# Blocking queries — find lock contention
npx supabase inspect db blocking --linked

# Replication slots — check replication health
npx supabase inspect db replication-slots --linked

Step 2: Query Analytics with pg_stat_statements and Log Drains

Enable

pg_stat_statements

-- Enable the extension (Dashboard > Database > Extensions, or SQL)
create extension if not exists pg_stat_statements;

-- Top 20 slowest queries by average execution time
select
  substring(query, 1, 80) as query_preview,
  calls,
  round(mean_exec_time::numeric, 2) as avg_ms,
  round(max_exec_time::numeric, 2) as max_ms,
  round(total_exec_time::numeric, 2) as total_ms,
  rows
from pg_stat_statements
where mean_exec_time > 50
order by mean_exec_time desc
limit 20;

-- Most-called queries (high call count may indicate N+1 problems)
select
  substring(query, 1, 80) as query_preview,
  calls,
  round(mean_exec_time::numeric, 2) as avg_ms,
  rows
from pg_stat_statements
order by calls desc
limit 20;

-- Real-time connection monitoring
select
  state,
  count(*) as connections,
  max(age(now(), state_change))::text as longest_duration
from pg_stat_activity
where datname = current_database()
group by state
order by connections desc;

-- Reset stats after optimization (to measure improvement)
select pg_stat_statements_reset();

Log drains forward Supabase logs to external aggregation tools:

# Add a Datadog log drain
npx supabase log-drains add \
  --name datadog-drain \
  --type datadog \
  --datadog-api-key "$DATADOG_API_KEY" \
  --datadog-region us1 \
  --linked

# Add a custom HTTP log drain (Logflare, Axiom, etc.)
npx supabase log-drains add \
  --name custom-drain \
  --type webhook \
  --url "https://api.logflare.app/logs/supabase" \
  --linked

# List active drains
npx supabase log-drains list --linked

# Remove a drain
npx supabase log-drains remove <drain-id> --linked

Log drain events include API requests, Auth events, Postgres logs, Storage operations, and Edge Function invocations.

Step 3: Custom Metrics, Alerting, and Health Checks

Custom metrics via Edge Functions — emit structured events for business-level monitoring:

// supabase/functions/collect-metrics/index.ts
import { createClient } from '@supabase/supabase-js';
import { serve } from 'https://deno.land/std@0.177.0/http/server.ts';

serve(async () => {
  const supabase = createClient(
    Deno.env.get('SUPABASE_URL')!,
    Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!
  );

  // Collect quota-relevant metrics
  const { count: userCount } = await supabase
    .from('profiles')
    .select('*', { count: 'exact', head: true });

  const { count: storageObjects } = await supabase
    .storage.from('uploads')
    .list('', { limit: 1, offset: 0 })
    .then(({ data }) => ({ count: data?.length ?? 0 }));

  const { data: dbSize } = await supabase
    .rpc('get_database_size');

  const metrics = {
    timestamp: new Date().toISOString(),
    user_count: userCount,
    db_size_mb: dbSize,
    storage_objects: storageObjects,
  };

  // Store metrics for trend analysis
  await supabase.from('app_metrics').insert(metrics);

  // Alert on quota thresholds
  const DB_LIMIT_MB = 8000; // 8GB Pro plan limit
  if (dbSize > DB_LIMIT_MB * 0.85) {
    console.warn(`[QUOTA_ALERT] Database at ${Math.round(dbSize / DB_LIMIT_MB * 100)}% capacity`);
    // Send alert via webhook, email, or Slack
  }

  return new Response(JSON.stringify(metrics), {
    headers: { 'Content-Type': 'application/json' },
  });
});

Schedule it with a cron trigger in

supabase/config.toml

[functions.collect-metrics]
schedule = "*/15 * * * *"  # Every 15 minutes

Health check endpoint for uptime monitoring (Uptime Robot, Pingdom, etc.):

// supabase/functions/health/index.ts
import { createClient } from '@supabase/supabase-js';
import { serve } from 'https://deno.land/std@0.177.0/http/server.ts';

serve(async () => {
  const supabase = createClient(
    Deno.env.get('SUPABASE_URL')!,
    Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!
  );

  const checks: Record<string, { status: string; latency_ms: number; detail?: string }> = {};

  // Database check
  const dbStart = Date.now();
  const { error: dbErr } = await supabase.rpc('version');
  checks.database = {
    status: dbErr ? 'unhealthy' : 'healthy',
    latency_ms: Date.now() - dbStart,
    ...(dbErr && { detail: dbErr.message }),
  };

  // Auth check
  const authStart = Date.now();
  const { error: authErr } = await supabase.auth.admin.listUsers({ perPage: 1 });
  checks.auth = {
    status: authErr ? 'unhealthy' : 'healthy',
    latency_ms: Date.now() - authStart,
  };

  // Storage check
  const storageStart = Date.now();
  const { error: storageErr } = await supabase.storage.listBuckets();
  checks.storage = {
    status: storageErr ? 'unhealthy' : 'healthy',
    latency_ms: Date.now() - storageStart,
  };

  const overall = Object.values(checks).every(c => c.status === 'healthy');
  const statusCode = overall ? 200 : 503;

  return new Response(
    JSON.stringify({ status: overall ? 'healthy' : 'degraded', checks, timestamp: new Date().toISOString() }),
    { status: statusCode, headers: { 'Content-Type': 'application/json' } }
  );
});

Real-time connection monitoring — track active Realtime connections:

import { createClient } from '@supabase/supabase-js';

const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
);

// Monitor channel state changes
const channel = supabase.channel('monitoring');

channel
  .on('system', { event: '*' }, (payload) => {
    console.log(`[REALTIME] System event:`, payload);
  })
  .subscribe((status) => {
    console.log(`[REALTIME] Connection status: ${status}`);
    if (status === 'CHANNEL_ERROR') {
      console.error('[REALTIME] Connection lost — will auto-reconnect');
    }
  });

Output

• Dashboard reports configured for API, database, and auth monitoring
• CLI inspect commands available for Postgres diagnostics (table sizes, index usage, cache hits, sequential scans, long-running queries)

• pg_stat_statements

  enabled with slow-query and high-frequency-query views
• Log drains forwarding to external tools (Datadog, Logflare, or webhook)
• Custom metrics Edge Function collecting quota-relevant data on a schedule
• Health check endpoint returning per-service status with latency
• Alerting on quota thresholds (database size, user count)

Error Handling

pg_stat_statements

supabase inspect db

supabase link --project-ref <ref>

supabase log-drains list

detail

schedule

[functions.<name>]

schedule

inspect db seq-scans

inspect db blocking

Examples

Quick Diagnostic Script

#!/bin/bash
# supabase-health-check.sh — run all inspect commands at once
echo "=== Table Sizes ==="
npx supabase inspect db table-sizes --linked
echo ""
echo "=== Cache Hit Ratio ==="
npx supabase inspect db cache-hit --linked
echo ""
echo "=== Sequential Scans ==="
npx supabase inspect db seq-scans --linked
echo ""
echo "=== Long Running Queries ==="
npx supabase inspect db long-running-queries --linked
echo ""
echo "=== Index Usage ==="
npx supabase inspect db index-usage --linked

Metrics Table Schema

create table if not exists app_metrics (
  id bigint generated always as identity primary key,
  timestamp timestamptz not null default now(),
  user_count integer,
  db_size_mb numeric,
  storage_objects integer,
  api_requests_24h integer,
  avg_response_ms numeric
);

-- Index for time-series queries
create index idx_app_metrics_timestamp on app_metrics (timestamp desc);

-- Retention policy: keep 90 days
create or replace function cleanup_old_metrics()
returns void as $$
  delete from app_metrics where timestamp < now() - interval '90 days';
$$ language sql;

Resources

• Supabase Logs & Analytics
• Database Inspect Commands
• Log Drains
• Edge Functions Scheduling
• pg_stat_statements
• Supabase JS Client

Next Steps

For incident response procedures, see

supabase-incident-runbook

supabase-performance-tuning