When Slider deploys an app on Yarn, the component instances run in containers created by YARN. If you need to debug the application you need to look into the logs produced by the component instance.

Ensure that logs are kept around.

Set "yarn.nodemanager.delete.debug-delay-sec" to some non-zero value. For example, 3600 for an hour.

Logs are created at directory identified by "yarn.nodemanager.log-dirs".

Finding the logs

Find the application id for your app. Hovering over the application name on the Slider View front page will show you the application id. For example,http://c6401.ambari.apache.org:8080/views/SLIDER/0.1.0/Slider/#/apps/1401500566781_3/summary denotes the application id 1401500566781_0003. The application id is of the form (cluster timestamp i.e. start-time of the ResourceManager along with a monotonically increasing counter for the application).

Go to the log directory and search for the folder associated with the application. Under the folder you will see log folders for each container. For example:

./log/application_1401500566781_0003/container_1401500566781_0003_01_000004/slider-agent.log
./log/application_1401500566781_0003/container_1401500566781_0003_01_000001/slider-err.txt
./log/application_1401500566781_0003/container_1401500566781_0003_01_000006

shows, log path for 3 containers, 000004, 000001, and 000006.

If the application is configured to emit logs to a child directory of ${AGENT_LOG_ROOT} then the logs will be stored in a subfolder under container's log folder.

If the application is active, then the log locations for the last 10 container instances are available through the publisher service.

Go to the Tracking UI associated with the application instance. Find the Publisher Service URI. The log locations are at <Publisher Service>/slider/logfolders.

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