[SAMZA-169] Task initialization fails if changelog stream does not already exist

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.6.0
• Fix Version/s: 0.7.0
• Component/s: kafka, kv
• Assignee: Martin Kleppmann
• Reporter: Martin Kleppmann
• Created: 05/Mar/14 13:18
• Updated: 19/Mar/14 15:37
• Resolved: 06/Mar/14 21:11

Description

The first time you run a job that uses state with changelog (such as in SAMZA-152), you get the following exception:

2014-03-04 18:15:20 SamzaContainer [ERROR] Caught exception in process loop.
org.apache.samza.SamzaException: Missing a change log offset for SystemStreamPartition [partition=Partition [partition=1], system=kafka, stream=wikipedia-stats-changelog].
	at org.apache.samza.storage.TaskStorageManager$$anonfun$startConsumers$3$$anonfun$1.apply(TaskStorageManager.scala:84)
	at org.apache.samza.storage.TaskStorageManager$$anonfun$startConsumers$3$$anonfun$1.apply(TaskStorageManager.scala:84)
	at scala.collection.MapLike$class.getOrElse(MapLike.scala:128)
	at scala.collection.AbstractMap.getOrElse(Map.scala:58)
	at org.apache.samza.storage.TaskStorageManager$$anonfun$startConsumers$3.apply(TaskStorageManager.scala:84)
	at org.apache.samza.storage.TaskStorageManager$$anonfun$startConsumers$3.apply(TaskStorageManager.scala:81)
	at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:772)
	at scala.collection.MapLike$MappedValues$$anonfun$foreach$3.apply(MapLike.scala:245)
	at scala.collection.MapLike$MappedValues$$anonfun$foreach$3.apply(MapLike.scala:245)
	at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:772)
	at scala.collection.immutable.Map$Map1.foreach(Map.scala:109)
	at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:771)
	at scala.collection.MapLike$MappedValues.foreach(MapLike.scala:245)
	at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:771)
	at org.apache.samza.storage.TaskStorageManager.startConsumers(TaskStorageManager.scala:81)
	at org.apache.samza.storage.TaskStorageManager.init(TaskStorageManager.scala:60)
	at org.apache.samza.container.TaskInstance.startStores(TaskInstance.scala:103)
	at org.apache.samza.container.SamzaContainer$$anonfun$startStores$2.apply(SamzaContainer.scala:579)
	at org.apache.samza.container.SamzaContainer$$anonfun$startStores$2.apply(SamzaContainer.scala:579)
	at scala.collection.Iterator$class.foreach(Iterator.scala:727)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
	at scala.collection.MapLike$DefaultValuesIterable.foreach(MapLike.scala:206)
	at org.apache.samza.container.SamzaContainer.startStores(SamzaContainer.scala:579)
	at org.apache.samza.container.SamzaContainer.run(SamzaContainer.scala:504)
	at org.apache.samza.container.SamzaContainer$.main(SamzaContainer.scala:81)
	at org.apache.samza.container.SamzaContainer.main(SamzaContainer.scala)

If debug logging is turned on, the following telltale line appears in the log earlier:

2014-03-04 18:15:20 KafkaSystemAdmin [DEBUG] Got metadata for streams: Map(wikipedia-stats-changelog -> {TopicMetadata for topic wikipedia-stats-changelog -> 
No partition metadata for topic wikipedia-stats-changelog due to kafka.common.LeaderNotAvailableException})

Full log: https://gist.github.com/ept/1fecad1b2d79797990a8

Issue Links

• depends upon: SAMZA-168 Getting Kafka system metadata should back off on retry
• duplicates: SAMZA-108 Samza task hangs on startup with new state store