Not enough data to calculate spout lag

[jinhong lu]

Hi, all

    I found log  "Metrics Tick: Not enough data to calculate spout lag.” in my 
topo log and then the topo became very slow. I check the source:

  if (_partitions != null && _partitions.size() == _partitionToOffset.size()) {
……}else {
   LOG.info("Metrics Tick: Not enough data to calculate spout lag.");
}

But I have no idea what situation will cause  _partitions != null or 
_partitions.size() == _partitionToOffset.size().

Any situation will cause this warn, thanks ?


BR//lujinhong