public void SyncedRebalance()
{
lock (parent.rebalanceLock)
{
if (parent.isShuttingDown.Get())
{
return;
}
else
{
for (var i = 1; i <= parent.Config.RebalanceMaxRetries; i++)
{
Logger.InfoFormat("begin rebalancing consumer {0} try #{1}", consumerIdString, i);
var done = false;
Cluster cluster = null;
try
{
cluster = ZkUtils.GetCluster(parent.zkClient);
done = this.Rebalance(cluster);
}
catch (Exception e)
{
/** occasionally, we may hit a ZK exception because the ZK state is changing while we are iterating.
* For example, a ZK node can disappear between the time we get all children and the time we try to get
* the value of a child. Just let this go since another rebalance will be triggered.
**/
Logger.Info("Exception during rebalance", e);
}
Logger.InfoFormat("end rebalancing consumer {0} try #{1}", consumerIdString, i);
if (done)
{
return;
}
else
{
/* Here the cache is at a risk of being stale. To take future rebalancing decisions correctly, we should
* clear the cache */
Logger.Info("Rebalancing attempt failed. Clearing the cache before the next rebalancing operation is triggered");
}
// stop all fetchers and clear all the queues to avoid Data duplication
CloseFetchersForQueues(cluster, (IDictionary <string, IList <KafkaStream <TKey, TValue> > >)KafkaMessageAndMetadataStreams, parent.topicThreadIdAndQueues.Select(x => x.Value).ToList());
Thread.Sleep(parent.Config.RebalanceBackoffMs);
}
}
}
throw new ConsumerRebalanceFailedException(
consumerIdString + " can't rebalance after " + parent.Config.RebalanceMaxRetries + " retries");
}