DC/OS Software Development Kit Status: Alpha

Cassandra: Troubleshooting

Accessing Logs

Logs for the scheduler and all service nodes can be viewed from the DC/OS web interface.

In all cases, logs are generally piped to files named stdout and/or stderr.

To view logs for a given node, perform the following steps:

  1. Visit to access the DC/OS web interface.
  2. Navigate to Services and click on the service to be examined (default cassandra).
  3. In the list of tasks for the service, click on the task to be examined (scheduler is named after the service, nodes are each node-<NUM>-server).
  4. In the task details, click on the Logs tab to go into the log viewer. By default, you will see stdout, but stderr is also useful. Use the pull-down in the upper right to select the file to be examined.

You can also access the logs via the Mesos UI:

  1. Visit /mesos to view the Mesos UI.
  2. Click the Frameworks tab in the upper left to get a list of services running in the cluster.
  3. Navigate into the correct framework for your needs. The scheduler runs under marathon with a task name matching the service name (default PKGNAME). Service nodes run under a framework whose name matches the service name (default PKGNAME).
  4. You should now see two lists of tasks. Active Tasks are tasks currently running, and Completed Tasks are tasks that have exited. Click the Sandbox link for the task you wish to examine.
  5. The Sandbox view will list files named stdout and stderr. Click the file names to view the files in the browser, or click Download to download them to your system for local examination. Note that very old tasks will have their Sandbox automatically deleted to limit disk space usage.