Hi As you are using yarn log aggregation, yarn moves all the logs to hdfs after the application completes.
You can use following command to get the logs: yarn logs -applicationId <your application id> On Mon, 31 Jul 2017 at 3:17 am, John Zeng <johnz...@hotmail.com> wrote: > Thanks Riccardo for the valuable info. > > > Following your guidance, I looked at the Spark UI and figured out the > default logs location for executors is 'yarn/container-logs'. I ran my > Spark app again and I can see a new folder was created for it: > > > [root@john2 application_1501197841826_0013]# ls -l > total 24 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:07 > container_1501197841826_0013_01_000001 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:08 > container_1501197841826_0013_01_000002 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:08 > container_1501197841826_0013_01_000003 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:08 > container_1501197841826_0013_02_000001 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:08 > container_1501197841826_0013_02_000002 > drwx--x--- 2 yarn yarn 4096 Jul 30 10:08 > container_1501197841826_0013_02_000003 > > But when I tried to look into each its content, it was gone and there was > not file at all from the same place: > > [root@john2 application_1501197841826_0013]# vi > container_1501197841826_0013_* > [root@john2 application_1501197841826_0013]# ls -l > total 0 > [root@john2 application_1501197841826_0013]# pwd > /yarn/container-logs/application_1501197841826_0013 > > I believe Spark moves these logs to a different place. But where are they? > > Thanks > > John > > > > > ------------------------------ > *From:* Riccardo Ferrari <ferra...@gmail.com> > *Sent:* Saturday, July 29, 2017 8:18 PM > *To:* johnzengspark > *Cc:* User > *Subject:* Re: Logging in RDD mapToPair of Java Spark application > > Hi John, > > The reason you don't see the second sysout line is because is executed on > a different JVM (ie. Driver vs Executor). the second sysout line should be > available through the executor logs. Check the Executors tab. > > There are alternative approaches to manage log centralization however it > really depends on what are your requirements. > > Hope it helps, > > On Sat, Jul 29, 2017 at 8:09 PM, johnzengspark <johnz...@hotmail.com> > wrote: > >> Hi, All, >> >> Although there are lots of discussions related to logging in this news >> group, I did not find an answer to my specific question so I am posting >> mine >> with the hope that this will not cause a duplicated question. >> >> Here is my simplified Java testing Spark app: >> >> public class SparkJobEntry { >> public static void main(String[] args) { >> // Following line is in stdout from JobTracker UI >> System.out.println("argc=" + args.length); >> >> SparkConf conf = new >> SparkConf().setAppName("TestSparkApp"); >> JavaSparkContext sc = new JavaSparkContext(conf); >> JavaRDD<String> fileRDD = sc.textFile(args[0]); >> >> fileRDD.mapToPair(new PairFunction<String, String, >> String>() { >> >> private static final long serialVersionUID = 1L; >> >> @Override >> public Tuple2<String, String> call(String input) >> throws Exception { >> // Following line is not in stdout from >> JobTracker UI >> System.out.println("This line should be >> printed in stdout"); >> // Other code removed from here to make >> things simple >> return new Tuple2<String, String>("1", >> "Testing data"); >> }}).saveAsTextFile(args[0] + ".results"); >> } >> } >> >> What I expected from JobTracker UI is to see both stdout lines: first line >> is "argc=2" and second line is "This line should be printed in stdout". >> But >> I only see the first line which is outside of the 'mapToPair'. I actually >> have verified my 'mapToPair' is called and the statements after the second >> logging line were executed. The only issue for me is why the second >> logging >> is not in JobTracker UI. >> >> Appreciate your help. >> >> Thanks >> >> John >> >> >> >> -- >> View this message in context: >> http://apache-spark-user-list.1001560.n3.nabble.com/Logging-in-RDD-mapToPair-of-Java-Spark-application-tp29007.html >> Sent from the Apache Spark User List mailing list archive at Nabble.com. >> >> --------------------------------------------------------------------- >> To unsubscribe e-mail: user-unsubscr...@spark.apache.org >> >> > -- Best Regards, Ayan Guha