One more +1

On 9 Jul 2014 23:49, "Curtis Allen" <curtis.n.allen@gmail.com> wrote:
Thanks for the +1's I've went ahead and created a JIRA issue https://issues.apache.org/jira/browse/STORM-399 and pull request https://github.com/apache/incubator-storm/pull/183

Danijel and P. Taylor please +1 in JIRA 

Thanks again!


On Wed, Jul 9, 2014 at 2:48 PM, P. Taylor Goetz <ptgoetz@gmail.com> wrote:
I'm +1 as well.

On Jul 9, 2014, at 4:03 PM, Danijel Schiavuzzi <danijel@schiavuzzi.com> wrote:

I'm also +1 on this.

The old spout behaviour was perfectly fine. I guess maxOffsetBehind was added as a protection against fetching unavailable Kafka offsets, but it doesn't really make sense to me, in my Trident transactional topology where I can't afford to lose any data. I would rather have my spout stop processing data in this case, than skipping some offsets because of an arbitrary maxOffsetBehind config value. Others opinions may vary, but I think 
setting this to Long.MAX_VALUE would make a much better default, as it would be closer to the old spout behaviour.

On Wednesday, July 9, 2014, Curtis Allen <curtis.n.allen@gmail.com> wrote:

Hello,

I’ve recently upgraded to storm and storm-kafka 0.9.2-incubating, replacing the https://github.com/wurstmeister/storm-kafka-0.8-plus spout I was using previously.

I have a large kafka log that I needed processed. I started my topology with

storm.kafka.SpoutConfig spoutConfig = new SpoutConfig....
spoutConfig.forceFromStart = true;

I then needed to make some tweaks in my application code and restarted the topology with spoutConfig.forceFromStart = false. Expecting to pick up where I left off in my kafka log. Instead the kafka spout started from the latest offset. Upon investigation I found this log message in my storm worker logs

2014-07-09 18:02:15 s.k.PartitionManager [INFO] Read last commit offset from zookeeper: 15266940; old topology_id: ef3f1f89-f64c-4947-b6eb-0c7fb9adb9ea - new topology_id: 5747dba6-c947-4c4f-af4a-4f50a84817bf 
2014-07-09 18:02:15 s.k.PartitionManager [INFO] Last commit offset from zookeeper: 15266940
2014-07-09 18:02:15 s.k.PartitionManager [INFO] Commit offset 22092614 is more than 100000 behind, resetting to startOffsetTime=-2 
2014-07-09 18:02:15 s.k.PartitionManager [INFO] Starting Kafka prd-use1c-pr-08-kafka-kamq-0004:4 from offset 22092614

Digging in the storm-kafka spout I found this line
https://github.com/apache/incubator-storm/blob/master/external/storm-kafka/src/jvm/storm/kafka/PartitionManager.java#L95

To fix this problem I ended up setting my spout config like so

spoutConf.maxOffsetBehind = Long.MAX_VALUE;

Now finally to my question.

Why would the kafka spout skip to the latest offset if the current offset is more then 100000 behind by default?

This seems like a bad default value, the spout literally skipped over months of data without any warning.

Are the core contributors open to accepting a pull request that would set the default to Long.MAX_VALUE?

Thanks,

Curtis Allen



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