Indeed. And it would be very hard to diagnose this further by automated means because of the flexibility of the layers below. Typically, the exception thrown is simply the last thing tried and is not a reliable indicator of how the intended configuration failed.
On Mon, Aug 15, 2011 at 1:55 PM, Grant Ingersoll <[email protected]>wrote: > Isn't that what the exception from SLF4J is? > > On Aug 14, 2011, at 11:03 PM, Lance Norskog wrote: > > > It might help to add a startup hack that complains somewhere if SLF4J > > is not hooked up right. > > > > On Sat, Aug 13, 2011 at 3:51 PM, Ted Dunning <[email protected]> > wrote: > >> Also, SLF4J is not a logging package, but a logging facade. I think > that > >> you need slf4j *and* a specific logging package. You have slf4j-log4j, > but > >> it isn't clear you have have log4j. You may prefer to put the static > slf4j > >> binding in the class path to avoid the need for log4j. > >> > >> Logging packages are generally a pain in the butt since they tend to be > kind > >> of fancy in what they require on the classpath. > >> > >> On Sat, Aug 13, 2011 at 3:18 PM, Sean Owen <[email protected]> wrote: > >> > >>> The unhelpful comment is that, well, the problem is exactly what you've > >>> already said: there is no SLF4J binding in the classpath where it needs > to > >>> be. I suspect you're perhaps mixing up classpaths. Which actual Java > task > >>> isn't printing -- the Hadoop worker? are you sure the bindings are in > its > >>> classpath, versus say the classpath of the runner program? > >>> > >>> On Sat, Aug 13, 2011 at 9:39 PM, Dhruv Kumar <[email protected]> > wrote: > >>> > >>>> I am running into a strange problem which has started happening only > >>> after > >>>> I > >>>> did a svn update on Mahout's trunk this morning. > >>>> > >>>> For testing out MAHOUT-627, I have created some client code using > >>> IntelliJ > >>>> IDEA. In the jar artifact, I have added Mahout and Hadoop-0.20.203.0 > >>>> libraries as dependencies. > >>>> > >>>> If I run my code using: > >>>> > >>>> dhruv@tachyon:~/hadoop-0.20.203.0/bin$ ./hadoop -jar > >>>> ~/TestBaumWelch/out/artifacts/TestBaumWelch_jar/TestBaumWelch.jar > >>>> TestBaumWelch.TestBaumWelch > >>>> > >>>> I am unable to see any logs on the terminal or on the MapReduce web > admin > >>>> console (http://localhost:50030/jobtracker.jsp). The admin console > does > >>>> not > >>>> even show that any job is running. > >>>> > >>>> But, I can clearly tell that the program is executing, since I get a > >>> series > >>>> of map 100%, reduce 100% and other INFO messages one after the other > and > >>>> because it produces results in the output directories. > >>>> > >>>> However, when I run the Hadoop's canonical Word Count example which > does > >>>> not > >>>> depend on Mahout, I am able to see logs via the web admin console and > >>>> everything goes OK. > >>>> > >>>> > >>>> I suspect this is because of SLF4J on my system, there may be more > than > >>> one > >>>> class binding or none at all. Here are the warning messages emitted > soon > >>>> after I run the program: > >>>> > >>>> SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". > >>>> SLF4J: Defaulting to no-operation (NOP) logger implementation > >>>> SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for > >>> further > >>>> details. > >>>> > >>>> > >>>> However, slf4j is clearly on the classpath. > >>>> > >>>> For hadoop, a portion of echo $CLASSPATH reveals: > >>>> > >>>> :/home/dhruv/hadoop-0.20.203.0/bin/../lib/slf4j-log4j12-1.4.3.jar > >>>> > >>>> For mahout: > >>>> > >>>> > >>>> > >>> > /home/dhruv/mahout/examples/target/dependency/slf4j-api-1.6.1.jar:/home/dhruv/mahout/examples/target/dependency/slf4j-jcl-1.6.1.jar:/home/dhruv/mahout/examples/target/dependency/slf4j-log4j12-1.6.1.jar: > >>>> > >>>> > >>>> Also, during Mahout's "mvn install" the slf4j is being added since I > can > >>>> see > >>>> the following messages: > >>>> > >>>> [INFO] org/slf4j/ already added, skipping > >>>> [INFO] org/slf4j/impl/ already added, skipping > >>>> [INFO] org/slf4j/impl/StaticLoggerBinder.class already added, skipping > >>>> [INFO] org/slf4j/impl/StaticMarkerBinder.class already added, skipping > >>>> [INFO] org/slf4j/impl/StaticMDCBinder.class already added, skipping > >>>> > >>>> Has any one else run into a problem like this before? > >>>> > >>> > >> > > > > > > > > -- > > Lance Norskog > > [email protected] > > -------------------------------------------- > Grant Ingersoll > > >
