flink日志问题

flink实时任务，使用了debug，但taskManager上运行的任务一直没有debug级别的日志，只有info日志。

最终回到flink配置，弄清flink/conf下面的日志配置文件作用

log4j.properties：在yarn模式下，jobManager和taskManager上用的log配置都依赖于它！

log4j-cli.properties：flink run启动时的日志依赖于该配置

log4j-yarn-session.properties：用yarn-session.sh启动时的日志依赖于该配置

logback.xml、logback-console.xml、logback-yarn.xml分别对应上面三个日志文件

所以在具体的flink任务配置debug并不能生效，如果需要看到taskManager，需要修改flink/conf/log4j.properties，比如设置DEBUG等级日志，如下

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# This affects logging for both user code and Flink

# log4j.rootLogger=INFO, file

log4j.rootLogger=DEBUG, file

# Uncomment this if you want to _only_ change Flink's logging
#log4j.logger.org.apache.flink=INFO

# The following lines keep the log level of common libraries/connectors on
# log level INFO. The root logger does not override this. You have to manually
# change the log levels here.
log4j.logger.akka=INFO
log4j.logger.org.apache.kafka=INFO
log4j.logger.org.apache.hadoop=INFO
log4j.logger.org.apache.zookeeper=INFO

# Log all infos in the given file
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.file=${log.file}
log4j.appender.file.append=false
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %-60c %x - %m%n

# Suppress the irrelevant (wrong) warnings from the Netty channel handler
log4j.logger.org.apache.flink.shaded.akka.org.jboss.netty.channel.DefaultChannelPipeline=ERROR, file