Chris Riccomini created SAMZA-374:
-------------------------------------
Summary: Need to be able to change SSP Grouper
Key: SAMZA-374
URL: https://issues.apache.org/jira/browse/SAMZA-374
Project: Samza
Issue Type: Bug
Components: container
Affects Versions: 0.8.0
Reporter: Chris Riccomini
Fix For: 0.8.0
I recently ran a job with checkpointing enabled. The default grouper was used
(group by partition). I then decided that I wanted to increase parallelism, so
I set the grouper to group by SSP. This cause the container to get wedged in
this loop:
{noformat}
2014-08-08 18:56:06 VerifiableProperties [INFO] Verifying properties
2014-08-08 18:56:06 VerifiableProperties [INFO] Property client.id is
overridden to
samza_checkpoint_manager-repartition_by_treeid-i001-1407524103759-2
2014-08-08 18:56:06 VerifiableProperties [INFO] Property metadata.broker.list
is overridden to kafka-vip-e:10251
2014-08-08 18:56:06 VerifiableProperties [INFO] Property request.timeout.ms is
overridden to 60000
2014-08-08 18:56:06 ClientUtils$ [INFO] Fetching metadata from broker
id:0,host:kafka-vip-e,port:10251 with correlation id 7 for 1 topic(s)
Set(__samza_checkpoint_ver_1_for_my-job_i001)
2014-08-08 18:56:06 BlockingChannel [DEBUG] Created socket with SO_TIMEOUT =
60000 (requested 60000), SO_RCVBUF = 43690 (requested -1), SO_SNDBUF = 102400
(requested 102400).
2014-08-08 18:56:06 SyncProducer [INFO] Connected to kafka-vip-e:10251 for
producing
2014-08-08 18:56:06 SyncProducer [INFO] Disconnecting from kafka-vip-e:10251
2014-08-08 18:56:06 ClientUtils$ [DEBUG] Successfully fetched metadata for 1
topic(s) Set(__samza_checkpoint_ver_1_for_my-job_i001)
2014-08-08 18:56:06 KafkaCheckpointManager [INFO] Connecting to leader
app196.:10251 for topic __samza_checkpoint_ver_1_for_my-job_i001 and to fetch
all checkpoint messages.
2014-08-08 18:56:06 KafkaCheckpointManager [INFO] Got offset 13 for topic
__samza_checkpoint_ver_1_for_my-job_i001 and partition 0. Attempting to fetch
messages for changelog partition mapping.
2014-08-08 18:56:06 SimpleConsumer [DEBUG] Disconnecting from app196.:10251
2014-08-08 18:56:06 BlockingChannel [DEBUG] Created socket with SO_TIMEOUT =
60000 (requested 60000), SO_RCVBUF = 65536 (requested 65536), SO_SNDBUF = 8192
(requested -1).
2014-08-08 18:56:06 KafkaCheckpointManager [INFO] Get latest offset 80626 for
topic __samza_checkpoint_ver_1_for_my-job_i001 and partition 0.
2014-08-08 18:56:07 SimpleConsumer [DEBUG] Disconnecting from app196.:10251
2014-08-08 18:56:07 KafkaCheckpointManager [WARN] While trying to read last
changelog partition mapping entry for topic
__samza_checkpoint_ver_1_for_my-job_i001 and partition 0:
org.apache.samza.SamzaException: Exception while deserializing checkpoint key.
Retrying.
2014-08-08 18:56:07 KafkaCheckpointManager [DEBUG] Exception detail:
org.apache.samza.SamzaException: Exception while deserializing checkpoint key
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointLogKey$.fromBytes(KafkaCheckpointLogKey.scala:177)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1$$anonfun$apply$9.apply(KafkaCheckpointManager.scala:300)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1$$anonfun$apply$9.apply(KafkaCheckpointManager.scala:292)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at kafka.utils.IteratorTemplate.foreach(IteratorTemplate.scala:32)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at kafka.message.MessageSet.foreach(MessageSet.scala:67)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1.apply(KafkaCheckpointManager.scala:292)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1.apply(KafkaCheckpointManager.scala:254)
at
org.apache.samza.util.ExponentialSleepStrategy.run(ExponentialSleepStrategy.scala:82)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager.readLog(KafkaCheckpointManager.scala:253)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager.readChangeLogPartitionMapping(KafkaCheckpointManager.scala:240)
at
org.apache.samza.util.Util$.getTaskNameToChangeLogPartitionMapping(Util.scala:280)
at
org.apache.samza.job.yarn.SamzaAppMasterTaskManager.<init>(SamzaAppMasterTaskManager.scala:79)
at
org.apache.samza.job.yarn.SamzaAppMaster$.main(SamzaAppMaster.scala:90)
at org.apache.samza.job.yarn.SamzaAppMaster.main(SamzaAppMaster.scala)
Caused by:
org.apache.samza.checkpoint.kafka.DifferingSystemStreamPartitionGrouperFactoryValues:
Checkpoint key's SystemStreamPartition Grouper factory
(org.apache.samza.container.grouper.stream.GroupByPartitionFactory) does not
match value from current configuration
(org.apache.samza.container.grouper.stream.GroupBySystemStreamPartitionFactory).
This likely means the SystemStreamPartitionGrouper was changed between job
runs, which is not supported.
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointLogKey$.fromBytes(KafkaCheckpointLogKey.scala:170)
... 15 more
2014-08-08 18:56:17 VerifiableProperties [INFO] Verifying properties
2014-08-08 18:56:17 VerifiableProperties [INFO] Property client.id is
overridden to
samza_checkpoint_manager-repartition_by_treeid-i001-1407524103759-2
2014-08-08 18:56:17 VerifiableProperties [INFO] Property metadata.broker.list
is overridden to kafka-vip-e:10251
2014-08-08 18:56:17 VerifiableProperties [INFO] Property request.timeout.ms is
overridden to 60000
2014-08-08 18:56:17 ClientUtils$ [INFO] Fetching metadata from broker
id:0,host:kafka-vip-e,port:10251 with correlation id 8 for 1 topic(s)
Set(__samza_checkpoint_ver_1_for_my-job_i001)
2014-08-08 18:56:17 BlockingChannel [DEBUG] Created socket with SO_TIMEOUT =
60000 (requested 60000), SO_RCVBUF = 43690 (requested -1), SO_SNDBUF = 102400
(requested 102400).
2014-08-08 18:56:17 SyncProducer [INFO] Connected to kafka-vip-e:10251 for
producing
2014-08-08 18:56:17 SyncProducer [INFO] Disconnecting from kafka-vip-e:10251
2014-08-08 18:56:17 ClientUtils$ [DEBUG] Successfully fetched metadata for 1
topic(s) Set(__samza_checkpoint_ver_1_for_my-job_i001)
2014-08-08 18:56:17 KafkaCheckpointManager [INFO] Connecting to leader
app196.:10251 for topic __samza_checkpoint_ver_1_for_my-job_i001 and to fetch
all checkpoint messages.
2014-08-08 18:56:17 KafkaCheckpointManager [INFO] Got offset 14 for topic
__samza_checkpoint_ver_1_for_my-job_i001 and partition 0. Attempting to fetch
messages for changelog partition mapping.
2014-08-08 18:56:17 SimpleConsumer [DEBUG] Disconnecting from app196.:10251
2014-08-08 18:56:17 BlockingChannel [DEBUG] Created socket with SO_TIMEOUT =
60000 (requested 60000), SO_RCVBUF = 65536 (requested 65536), SO_SNDBUF = 8192
(requested -1).
2014-08-08 18:56:17 KafkaCheckpointManager [INFO] Get latest offset 80626 for
topic __samza_checkpoint_ver_1_for_my-job_i001 and partition 0.
2014-08-08 18:56:17 SimpleConsumer [DEBUG] Disconnecting from app196.:10251
2014-08-08 18:56:17 KafkaCheckpointManager [WARN] While trying to read last
changelog partition mapping entry for topic
__samza_checkpoint_ver_1_for_my-job_i001 and partition 0:
org.apache.samza.SamzaException: Exception while deserializing checkpoint key.
Retrying.
2014-08-08 18:56:17 KafkaCheckpointManager [DEBUG] Exception detail:
org.apache.samza.SamzaException: Exception while deserializing checkpoint key
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointLogKey$.fromBytes(KafkaCheckpointLogKey.scala:177)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1$$anonfun$apply$9.apply(KafkaCheckpointManager.scala:300)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1$$anonfun$apply$9.apply(KafkaCheckpointManager.scala:292)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at kafka.utils.IteratorTemplate.foreach(IteratorTemplate.scala:32)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at kafka.message.MessageSet.foreach(MessageSet.scala:67)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1.apply(KafkaCheckpointManager.scala:292)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager$$anonfun$readLog$1.apply(KafkaCheckpointManager.scala:254)
at
org.apache.samza.util.ExponentialSleepStrategy.run(ExponentialSleepStrategy.scala:82)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager.readLog(KafkaCheckpointManager.scala:253)
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointManager.readChangeLogPartitionMapping(KafkaCheckpointManager.scala:240)
at
org.apache.samza.util.Util$.getTaskNameToChangeLogPartitionMapping(Util.scala:280)
at
org.apache.samza.job.yarn.SamzaAppMasterTaskManager.<init>(SamzaAppMasterTaskManager.scala:79)
at
org.apache.samza.job.yarn.SamzaAppMaster$.main(SamzaAppMaster.scala:90)
at org.apache.samza.job.yarn.SamzaAppMaster.main(SamzaAppMaster.scala)
Caused by:
org.apache.samza.checkpoint.kafka.DifferingSystemStreamPartitionGrouperFactoryValues:
Checkpoint key's SystemStreamPartition Grouper factory
(org.apache.samza.container.grouper.stream.GroupByPartitionFactory) does not
match value from current configuration
(org.apache.samza.container.grouper.stream.GroupBySystemStreamPartitionFactory).
This likely means the SystemStreamPartitionGrouper was changed between job
runs, which is not supported.
at
org.apache.samza.checkpoint.kafka.KafkaCheckpointLogKey$.fromBytes(KafkaCheckpointLogKey.scala:170)
... 15 more
{noformat}
I'm knowingly breaking grouping semantics because my job doesn't need it. As I
recall, this was discussed in SAMZA-123, and we were all worried about people
accidentally breaking their state/grouping, so we hard fail when the grouper is
changed. The problem is, I can't change the checkpoint topic name, nor is it
easy for me to delete the checkpoint messages in the topic, so I'm kind of
stuck.
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