Hi Akhil - I tried your suggestions and tried varying my partition sizes. Reducing the number of partitions led to memory errors (presumably - I saw IOExceptions much sooner).
With the settings you provided the program ran for longer but ultimately crashes in the same way. I would like to understand what is going on internally leading to this. Could this be related to garbage collection? On Oct 10, 2014 3:19 AM, "Akhil Das" <ak...@sigmoidanalytics.com> wrote: > You could be hitting this issue > <https://issues.apache.org/jira/browse/SPARK-3633> (or similar). You can > try the following workarounds: > > sc.set("spark.core.connection.ack.wait.timeout","600") > sc.set("spark.akka.frameSize","50") > Also reduce the number of partitions, you could be hitting the kernel's > ulimit. I faced this issue and it was gone when i dropped the partitions > from 1600 to 200. > > Thanks > Best Regards > > On Fri, Oct 10, 2014 at 5:58 AM, Ilya Ganelin <ilgan...@gmail.com> wrote: > >> Hi all – I could use some help figuring out a couple of exceptions I’ve >> been getting regularly. >> >> I have been running on a fairly large dataset (150 gigs). With smaller >> datasets I don't have any issues. >> >> My sequence of operations is as follows – unless otherwise specified, I >> am not caching: >> >> Map a 30 million row x 70 col string table to approx 30 mil x 5 string >> (For read as textFile I am using 1500 partitions) >> >> From that, map to ((a,b), score) and reduceByKey, numPartitions = 180 >> >> Then, extract distinct values for A and distinct values for B. (I cache >> the output of distinct), , numPartitions = 180 >> >> Zip with index for A and for B (to remap strings to int) >> >> Join remapped ids with original table >> >> This is then fed into MLLIBs ALS algorithm. >> >> I am running with: >> >> Spark version 1.02 with CDH5.1 >> >> numExecutors = 8, numCores = 14 >> >> Memory = 12g >> >> MemoryFration = 0.7 >> >> KryoSerialization >> >> My issue is that the code runs fine for a while but then will >> non-deterministically crash with either file IOExceptions or the following >> obscure error: >> >> 14/10/08 13:29:59 INFO TaskSetManager: Loss was due to >> java.io.IOException: Filesystem closed [duplicate 10] >> >> 14/10/08 13:30:08 WARN TaskSetManager: Loss was due to >> java.io.FileNotFoundException >> >> java.io.FileNotFoundException: >> /opt/cloudera/hadoop/1/yarn/nm/usercache/zjb238/appcache/application_1412717093951_0024/spark-local-20141008131827-c082/1c/shuffle_3_117_354 >> (No such file or directory) >> >> Looking through the logs, I see the IOException in other places but it >> appears to be non-catastrophic. The FileNotFoundException, however, is. I >> have found the following stack overflow that at least seems to address the >> IOException: >> >> >> http://stackoverflow.com/questions/24038908/spark-fails-on-big-shuffle-jobs-with-java-io-ioexception-filesystem-closed >> >> But I have not found anything useful at all with regards to the app cache >> error. >> >> Any help would be much appreciated. >> > >
