supabase-observability

Supabase Observability

Overview

Monitor Supabase projects end-to-end: Dashboard reports for API/database/auth metrics, supabase inspect db CLI for deep Postgres diagnostics, pg_stat_statements for query analytics, log drains for external aggregation, Edge Functions for custom metrics, and alerting on quota thresholds.

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:

Report	What It Shows
API Requests	Total requests, response times, error rates by endpoint
Database	Active connections, query counts, replication lag
Auth Usage	Signups, logins, provider breakdown, failed attempts
Storage	Bandwidth, object counts, bucket usage
Realtime	Active connections, messages per second, channel counts

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 for detailed query-level metrics:

-- 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

Issue	Cause	Solution
pg_stat_statements returns no rows	Extension not enabled	Enable via Dashboard > Database > Extensions
supabase inspect db fails	CLI not linked to project	Run supabase link --project-ref <ref>
Log drain not receiving events	API key invalid or region mismatch	Verify credentials; check supabase log-drains list
Cache hit ratio below 95%	Working set exceeds RAM	Upgrade compute add-on or optimize queries
Health check returns 503	One or more services degraded	Check detail field in response; verify service role key
Edge Function cron not firing	Missing schedule in config.toml	Add [functions.<name>] with schedule field and redeploy
Long-running queries growing	Missing indexes or lock contention	Run inspect db seq-scans and 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 a

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