It's a really noticeable overhead, without the cache you're basically pulling every message twice due to prefetching.
On Wed, Sep 7, 2016 at 3:23 PM, Srikanth <srikanth...@gmail.com> wrote: > Yea, disabling cache was not going to be my permanent solution either. > I was going to ask how big an overhead is that? > > It happens intermittently and each time it happens retry is successful. > > Srikanth > > On Wed, Sep 7, 2016 at 3:55 PM, Cody Koeninger <c...@koeninger.org> wrote: >> >> That's not what I would have expected to happen with a lower cache >> setting, but in general disabling the cache isn't something you want >> to do with the new kafka consumer. >> >> >> As far as the original issue, are you seeing those polling errors >> intermittently, or consistently? From your description, it sounds >> like retry is working correctly. >> >> >> On Wed, Sep 7, 2016 at 2:37 PM, Srikanth <srikanth...@gmail.com> wrote: >> > Setting those two results in below exception. >> > No.of executors < no.of partitions. Could that be triggering this? >> > >> > 16/09/07 15:33:13 ERROR Executor: Exception in task 2.0 in stage 2.0 >> > (TID 9) >> > java.util.ConcurrentModificationException: KafkaConsumer is not safe for >> > multi-threaded access >> > at >> > >> > org.apache.kafka.clients.consumer.KafkaConsumer.acquire(KafkaConsumer.java:1430) >> > at >> > >> > org.apache.kafka.clients.consumer.KafkaConsumer.close(KafkaConsumer.java:1360) >> > at >> > >> > org.apache.spark.streaming.kafka010.CachedKafkaConsumer$$anon$1.removeEldestEntry(CachedKafkaConsumer.scala:128) >> > at java.util.LinkedHashMap.afterNodeInsertion(Unknown Source) >> > at java.util.HashMap.putVal(Unknown Source) >> > at java.util.HashMap.put(Unknown Source) >> > at >> > >> > org.apache.spark.streaming.kafka010.CachedKafkaConsumer$.get(CachedKafkaConsumer.scala:158) >> > at >> > >> > org.apache.spark.streaming.kafka010.KafkaRDD$KafkaRDDIterator.<init>(KafkaRDD.scala:210) >> > at >> > org.apache.spark.streaming.kafka010.KafkaRDD.compute(KafkaRDD.scala:185) >> > at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319) >> > at org.apache.spark.rdd.RDD.iterator(RDD.scala:283) >> > at >> > org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38) >> > at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319) >> > at org.apache.spark.rdd.RDD.iterator(RDD.scala:283) >> > at >> > org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38) >> > at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319) >> > at org.apache.spark.rdd.RDD.iterator(RDD.scala:283) >> > at >> > org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38) >> > at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319) >> > at org.apache.spark.rdd.RDD.iterator(RDD.scala:283) >> > at >> > >> > org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:79) >> > at >> > >> > org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:47) >> > at org.apache.spark.scheduler.Task.run(Task.scala:85) >> > at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274) >> > at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) >> > at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) >> > at java.lang.Thread.run(Unknown Source) >> > >> > >> > On Wed, Sep 7, 2016 at 3:07 PM, Cody Koeninger <c...@koeninger.org> >> > wrote: >> >> >> >> you could try setting >> >> >> >> spark.streaming.kafka.consumer.cache.initialCapacity >> >> >> >> spark.streaming.kafka.consumer.cache.maxCapacity >> >> >> >> to 1 >> >> >> >> On Wed, Sep 7, 2016 at 2:02 PM, Srikanth <srikanth...@gmail.com> wrote: >> >> > I had a look at the executor logs and noticed that this exception >> >> > happens >> >> > only when using the cached consumer. >> >> > Every retry is successful. This is consistent. >> >> > One possibility is that the cached consumer is causing the failure as >> >> > retry >> >> > clears it. >> >> > Is there a way to disable cache and test this? >> >> > Again, kafkacat is running fine on the same node. >> >> > >> >> > 16/09/07 16:00:00 INFO Executor: Running task 1.0 in stage 138.0 (TID >> >> > 7849) >> >> > 16/09/07 16:00:00 INFO Executor: Running task 3.0 in stage 138.0 (TID >> >> > 7851 >> >> > >> >> > 16/09/07 16:00:00 INFO KafkaRDD: Computing topic mt_event, partition >> >> > 2 >> >> > offsets 57079162 -> 57090330 >> >> > 16/09/07 16:00:00 INFO KafkaRDD: Computing topic mt_event, partition >> >> > 0 >> >> > offsets 57098866 -> 57109957 >> >> > 16/09/07 16:00:00 INFO Executor: Finished task 3.0 in stage 138.0 >> >> > (TID >> >> > 7851). 1030 bytes result sent to driver >> >> > 16/09/07 16:00:02 ERROR Executor: Exception in task 1.0 in stage >> >> > 138.0 >> >> > (TID >> >> > 7849) >> >> > java.lang.AssertionError: assertion failed: Failed to get records for >> >> > spark-executor-StreamingPixelCount1 mt_event 0 57100069 after polling >> >> > for >> >> > 2048 >> >> > at scala.Predef$.assert(Predef.scala:170) >> >> > at >> >> > >> >> > >> >> > org.apache.spark.streaming.kafka010.CachedKafkaConsumer.get(CachedKafkaConsumer.scala:74) >> >> > at >> >> > >> >> > >> >> > org.apache.spark.streaming.kafka010.KafkaRDD$KafkaRDDIterator.next(KafkaRDD.scala:227) >> >> > at >> >> > >> >> > >> >> > org.apache.spark.streaming.kafka010.KafkaRDD$KafkaRDDIterator.next(KafkaRDD.scala:193) >> >> > >> >> > 16/09/07 16:00:02 INFO CoarseGrainedExecutorBackend: Got assigned >> >> > task >> >> > 7854 >> >> > 16/09/07 16:00:02 INFO Executor: Running task 1.1 in stage 138.0 (TID >> >> > 7854) >> >> > 16/09/07 16:00:02 INFO KafkaRDD: Computing topic mt_event, partition >> >> > 0 >> >> > offsets 57098866 -> 57109957 >> >> > 16/09/07 16:00:02 INFO CachedKafkaConsumer: Initial fetch for >> >> > spark-executor-StreamingPixelCount1 mt_event 0 57098866 >> >> > >> >> > 16/09/07 16:00:03 INFO Executor: Finished task 1.1 in stage 138.0 >> >> > (TID >> >> > 7854). 1103 bytes result sent to driver >> >> > >> >> > >> >> > >> >> > On Wed, Aug 24, 2016 at 2:13 PM, Srikanth <srikanth...@gmail.com> >> >> > wrote: >> >> >> >> >> >> Thanks Cody. Setting poll timeout helped. >> >> >> Our network is fine but brokers are not fully provisioned in test >> >> >> cluster. >> >> >> But there isn't enough load to max out on broker capacity. >> >> >> Curious that kafkacat running on the same node doesn't have any >> >> >> issues. >> >> >> >> >> >> Srikanth >> >> >> >> >> >> On Tue, Aug 23, 2016 at 9:52 PM, Cody Koeninger <c...@koeninger.org> >> >> >> wrote: >> >> >>> >> >> >>> You can set that poll timeout higher with >> >> >>> >> >> >>> spark.streaming.kafka.consumer.poll.ms >> >> >>> >> >> >>> but half a second is fairly generous. I'd try to take a look at >> >> >>> what's going on with your network or kafka broker during that time. >> >> >>> >> >> >>> On Tue, Aug 23, 2016 at 4:44 PM, Srikanth <srikanth...@gmail.com> >> >> >>> wrote: >> >> >>> > Hello, >> >> >>> > >> >> >>> > I'm getting the below exception when testing Spark 2.0 with Kafka >> >> >>> > 0.10. >> >> >>> > >> >> >>> >> 16/08/23 16:31:01 INFO AppInfoParser: Kafka version : 0.10.0.0 >> >> >>> >> 16/08/23 16:31:01 INFO AppInfoParser: Kafka commitId : >> >> >>> >> b8642491e78c5a13 >> >> >>> >> 16/08/23 16:31:01 INFO CachedKafkaConsumer: Initial fetch for >> >> >>> >> spark-executor-example mt_event 0 15782114 >> >> >>> >> 16/08/23 16:31:01 INFO AbstractCoordinator: Discovered >> >> >>> >> coordinator >> >> >>> >> 10.150.254.161:9233 (id: 2147483646 rack: null) for group >> >> >>> >> spark-executor-example. >> >> >>> >> 16/08/23 16:31:02 ERROR Executor: Exception in task 0.0 in stage >> >> >>> >> 1.0 >> >> >>> >> (TID >> >> >>> >> 6) >> >> >>> >> java.lang.AssertionError: assertion failed: Failed to get >> >> >>> >> records >> >> >>> >> for >> >> >>> >> spark-executor-example mt_event 0 15782114 after polling for 512 >> >> >>> >> at scala.Predef$.assert(Predef.scala:170) >> >> >>> >> at >> >> >>> >> >> >> >>> >> >> >> >>> >> >> >> >>> >> org.apache.spark.streaming.kafka010.CachedKafkaConsumer.get(CachedKafkaConsumer.scala:74) >> >> >>> >> at >> >> >>> >> >> >> >>> >> >> >> >>> >> >> >> >>> >> org.apache.spark.streaming.kafka010.KafkaRDD$KafkaRDDIterator.next(KafkaRDD.scala:227) >> >> >>> >> at >> >> >>> >> >> >> >>> >> >> >> >>> >> >> >> >>> >> org.apache.spark.streaming.kafka010.KafkaRDD$KafkaRDDIterator.next(KafkaRDD.scala:193) >> >> >>> >> at scala.collection.Iterator$$anon$11.next(Iterator.scala:409) >> >> >>> > >> >> >>> > >> >> >>> > I get this error intermittently. Sometimes a few batches are >> >> >>> > scheduled >> >> >>> > and >> >> >>> > run fine. Then I get this error. >> >> >>> > kafkacat is able to fetch from this topic continuously. >> >> >>> > >> >> >>> > Full exception is here -- >> >> >>> > >> >> >>> > >> >> >>> > https://gist.github.com/SrikanthTati/c2e95c4ac689cd49aab817e24ec42767 >> >> >>> > >> >> >>> > Srikanth >> >> >> >> >> >> >> >> > >> > >> > > > --------------------------------------------------------------------- To unsubscribe e-mail: user-unsubscr...@spark.apache.org
