In the resource manager log, yarn would log the command for launching AM, this is very useful. But there's no such log in the NN log for launching containers. It would be difficult to diagnose when containers fails to launch due to some issue in the commands. Although user can look at the commands in the container launch script file, this is an internal things of yarn, usually user don't know that. In user's perspective, they only know what commands they specify when building yarn application.
2015-06-01 16:06:42,245 INFO org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncher: Command to launch container container_1433145984561_0001_01_000001 : $JAVA_HOME/bin/java -server -Djava.net.preferIPv4Stack=true -Dhadoop.metrics.log.level=WARN -Xmx1024m -Dlog4j.configuratorClass=org.apache.tez.common.TezLog4jConfigurator -Dlog4j.configuration=tez-container-log4j.properties -Dyarn.app.container.log.dir=<LOG_DIR> -Dtez.root.logger=info,CLA -Dsun.nio.ch.bugLevel='' org.apache.tez.dag.app.DAGAppMaster 1><LOG_DIR>/stdout 2><LOG_DIR>/stderr