Re: Problem to show logs in task managers

[Ana M. Martinez]

Hi Till,

Sorry for the delay (Xmas break). I have activated log aggregation on 
flink-conf.yaml with yarn.log-aggregation-enable: true (as I can’t find a 
yarn-site.xml).
But the command yarn logs -applicationId application_1451903796996_0008 gives 
me the following output:

INFO client.RMProxy: Connecting to ResourceManager at xxx
/var/log/hadoop-yarn/apps/hadoop/logs/application_1451903796996_0008does not 
exist.
Log aggregation has not completed or is not enabled

I’ve tried to restart the Flink JobManager and TaskManagers as follows:
./bin/yarn-session.sh -n 1 -tm 2048 -s 4
and then with a detached screen, run my application with ./bin/flink run -m 
yarn-cluster ...

I am not sure if my problem is that I am not setting the log-aggregation-enable 
property well or I am not restarting the Flink JobManager and TaskManagers as I 
should… Any idea?

Thanks,
Ana

On 18 Dec 2015, at 16:29, Till Rohrmann 
<trohrm...@apache.org<mailto:trohrm...@apache.org>> wrote:

In which log file are you exactly looking for the logging statements? And on 
what machine? You have to look on the machines on which the yarn container were 
started. Alternatively if you have log aggregation activated, then you can 
simply retrieve the log files via yarn logs.

Cheers,
Till

On Fri, Dec 18, 2015 at 3:49 PM, Ana M. Martinez 
<a...@cs.aau.dk<mailto:a...@cs.aau.dk>> wrote:
Hi Till,

Many thanks for your quick response.

I have modified the WordCountExample to re-reproduce my problem in a simple 
example.

I run the code below with the following command:
./bin/flink run -m yarn-cluster -yn 1 -ys 4 -yjm 1024 -ytm 1024 -c 
mypackage.WordCountExample ../flinklink.jar

And if I check the log file I see all logger messages except the one in the 
flatMap function of the inner LineSplitter class, which is actually the one I 
am most interested in.

Is that an expected behaviour?

Thanks,
Ana


import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class WordCountExample {
    static Logger logger = LoggerFactory.getLogger(WordCountExample.class);

    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env = 
ExecutionEnvironment.getExecutionEnvironment();

        logger.info("Entering application.");

    DataSet<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them. Stand, ho! Who's there?");

        List<Integer> elements = new ArrayList<Integer>();
        elements.add(0);


        DataSet<TestClass> set = env.fromElements(new TestClass(elements));

        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .withBroadcastSet(set, "set")
                .groupBy(0)
                .sum(1);

        wordCounts.print();


    }

    public static class LineSplitter implements FlatMapFunction<String, 
Tuple2<String, Integer>> {

        static Logger loggerLineSplitter = 
LoggerFactory.getLogger(LineSplitter.class);

        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> 
out) {
            loggerLineSplitter.info("Logger in LineSplitter.flatMap");
            for (String word : line.split(" ")) {
                out.collect(new Tuple2<String, Integer>(word, 1));
            }
        }
    }

    public static class TestClass implements Serializable {
        private static final long serialVersionUID = -2932037991574118651L;

        static Logger loggerTestClass = 
LoggerFactory.getLogger("WordCountExample.TestClass");

        List<Integer> integerList;
        public TestClass(List<Integer> integerList){
            this.integerList=integerList;
            loggerTestClass.info("Logger in TestClass");
        }


    }
}



On 17 Dec 2015, at 16:08, Till Rohrmann 
<trohrm...@apache.org<mailto:trohrm...@apache.org>> wrote:

Hi Ana,

you can simply modify the `log4j.properties` file in the `conf` directory. It 
should be automatically included in the Yarn application.

Concerning your logging problem, it might be that you have set the logging 
level too high. Could you share the code with us?

Cheers,
Till

On Thu, Dec 17, 2015 at 1:56 PM, Ana M. Martinez 
<a...@cs.aau.dk<mailto:a...@cs.aau.dk>> wrote:
Hi flink community,

I am trying to show log messages using log4j.
It works fine overall except for the messages I want to show in an inner class 
that implements org.apache.flink.api.common.aggregators.ConvergenceCriterion.
I am very new to this, but it seems that I’m having problems to show the 
messages included in the isConverged function, as it runs in the task managers?
E.g. the log messages in the outer class (before map-reduce operations) are 
properly shown.

I am also interested in providing my own log4j.properties file. I am using the 
./bin/flink run -m yarn-cluster on Amazon clusters.

Thanks,
Ana