New exception (for us) in high-level consumer code -- OK to ignore?

[Philip O'Toole]

Hello -- we're doing some heavy lifting now with our high-level based
consumer. We open a Consumer Connection per partition within the one JVM,
and are using Kafka 0.72. We saw a burst of the exceptions shown below. Is
this something we should be concerned about? Or is this the normal output
from rebalancing, as the consumer starts up?

Thanks,

Philip

2013-07-10 23:39:37,012 [ERROR] [ZookeeperConsumerConnector.error]
writer_writer0-1373499526097-ec0d4672 error during syncedRebalance
java.lang.NullPointerException
        at
kafka.utils.ZkUtils$.getChildrenParentMayNotExist(ZkUtils.scala:181)
        at kafka.utils.ZkUtils$.getCluster(ZkUtils.scala:202)
        at
kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener$$anonfun$syncedRebalance$1.apply$mcVI$sp(ZookeeperConsumerConnector.scala:447)
        at scala.collection.immutable.Range.foreach$mVc$sp(Range.scala:75)
        at
kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.syncedRebalance(ZookeeperConsumerConnector.scala:444)
        at
kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener$$anon$1.run(ZookeeperConsumerConnector.scala:401)
2013-07-10 23:39:37,013 [INFO] [ZookeeperConsumerConnector.info]
writer_writer0-1373499534602-35941a8c begin rebalancing consumer
writer_writer0-1373499534602-35941a8c try #1