title: Automatic vacuum of table "cloudsqladmin.public.heartbeat"
body: <p>We're experiencing some constant outages in our back-end that seem to correlate with peaks of high CPU usage for our Cloud SQL Postgres instance (v9.6)  </p>
  
  <p><a href="https://i.stack.imgur.com/ugnse.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ugnse.png" alt="postgres instance cpu usage"></a></p>
  
  <p>Taking a look to the <code>cloudsql.googleapis.com/postgres.log</code>, those high CPU peaks seems to also correlate to when the database is running an automatic vacuum of table <code>cloudsqladmin.public.heartbeat</code></p>
  
  <p><a href="https://i.stack.imgur.com/keoer.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/keoer.png" alt="postgres logs"></a></p>
  
  <p>We haven't found any documentation on what this table is and why is running autovacuum so often (our own tables doesn't seem to be affected by it).</p>
  
  <p>Is this normal? Should we tune the values for the autovacuum? Thanks in advance.</p>