title: __consumer_offsets topic with very big partitions
body: <p>I am using Kafka 2.0.0
  There are some partitions of the __consumer_offsets topic that are 500-700 GB and more than 5000-7000 segments. These segments are older than 2-3 months.
  There aren't errors in the logs and that topic is COMPACT as default.</p>
  <p>What could be the problem?
  Maybe a config or a consumer problem? or maybe a bug of kafka 2.0.0?
  What checks could I do?</p>
  <p>My settings:</p>
  <pre><code>log.cleaner.enable=true
  log.cleanup.policy = [delete]
  log.retention.bytes = -1
  log.segment.bytes = 268435456
  log.retention.hours = 72
  log.retention.check.interval.ms = 300000
  
  
  
  offsets.commit.required.acks = -1
  offsets.commit.timeout.ms = 5000
  offsets.load.buffer.size = 5242880
  offsets.retention.check.interval.ms = 600000
  offsets.retention.minutes = 10080
  offsets.topic.compression.codec = 0
  offsets.topic.num.partitions = 50
  offsets.topic.replication.factor = 3
  offsets.topic.segment.bytes = 104857600
  </code></pre>