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https://issues.apache.org/jira/browse/TEZ-4055?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16796849#comment-16796849
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Syed Shameerur Rahman commented on TEZ-4055:
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[~jeagles] , The issue of missing logs is not seen in case of hivecli(not HS2)
, To reproduce the issue
# Start HS2
# Connect to HS2 with beeline
Now we can see the issue of missing logs , Logs are not printed in beeline
console as well as ${sys:test.tmp.dir}/log/hive.log. The possible reason would
be while building tez it creates slf4j-log4j12-1.7.10.jar and
slf4j-api-1.7.10.jar where as hadoop has slf4j-log4j12-1.7.25.jar and
slf4j-api-1.7.25.jar which clearly conflicts.
Now when we connect to HS2 with beeline SLF4J gives such a warning *SLF4J:
Class path contains multiple SLF4J bindings.* According to the information in
[https://www.slf4j.org/codes.html#multiple_bindings] Even when multiple
bindings are present, SLF4J will pick one logging framework/implementation and
bind with it. The way SLF4J picks a binding is determined by the JVM and for
all practical purposes should be considered random. I think this is where the
issue arises.
Now coming to the solution i think rather than aligning the slf4j version to be
same as hadoop as a long time solution we can exclude the creation of slf4j
jars in tez with *<scope>provided</scope>* because any how JVM loads the slf4j
JAR from hadoop.
Any Suggestions ?
> Align slf4j version to be same as Hadoop3
> -----------------------------------------
>
> Key: TEZ-4055
> URL: https://issues.apache.org/jira/browse/TEZ-4055
> Project: Apache Tez
> Issue Type: Bug
> Affects Versions: 0.9.0, 0.9.1
> Reporter: Syed Shameerur Rahman
> Priority: Major
> Fix For: 0.10.0
>
> Attachments: TEZ-4055.patch
>
>
> Currently tez is using slf4j version 1.7.10 where as hadoop3 is using slf4j
> version 1.7.25 , due to conflicting version of slf4j version no logs are
> getting written in ${sys:test.tmp.dir}/log/hive.log. The statements
> LOG.info("") , LOG.error("") . are directed to write logs into
> ${sys:test.tmp.dir}/log/hive.log.
> When we connect to HS2 with beeline the slf4j jars are being searched
> SLF4J: Class path contains multiple SLF4J bindings.
> SLF4J: Found binding in [jar:<hadoop_location>]
> SLF4J: Found binding in [jar:<tez_location>]
> SLF4J: See [http://www.slf4j.org/codes.html#multiple_bindings] for an
> explanation.
> SLF4J: Actual binding is of type
> [org.apache.logging.slf4j.Log4jLoggerFactory]
> cc [~hitesh] [~kshukla]
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