title: Making postgres backups from heroku database followers
body: <p>Previously you used to be able to create database dumps of database followers on heroku. </p>
  
  <p><code>heroku pgbackups:capture HEROKU_FOLLOWER_COLOR --expire</code></p>
  
  <p>It has stopped working recently.</p>
  
  <p>If I <code>heroku logs --tail --ps pgbackups</code> I get</p>
  
  <pre><code>2013-03-07T17:27:49+00:00 app[pgbackups]: dump_progress: start
  2013-03-07T17:27:49+00:00 app[pgbackups]: pg_dump-9.2.1-64bit: [archiver (db)] query failed: ERROR:  cannot use serializable mode in a hot standby
  2013-03-07T17:27:49+00:00 app[pgbackups]: HINT:  You can use REPEATABLE READ instead.
  2013-03-07T17:27:49+00:00 app[pgbackups]: pg_dump-9.2.1-64bit: [archiver (db)] query was: SET TRANSACTION ISOLATION LEVEL SERIALIZABLE, READ ONLY, DEFERRABLE
  2013-03-07T17:27:49+00:00 app[pgbackups]: dump_progress:    0B
  2013-03-07T17:27:49+00:00 app[pgbackups]:
  2013-03-07T17:27:49+00:00 app[pgbackups]: dump_progress: error
  </code></pre>
  
  <p>Dumping from the main DATABASE_URL seems to work fine though.</p>
  
  <p>Is this a recent change in heroku platform or am I doing anything wrong?
  Also, is there a performance hit if I do a dump of the main database?</p>