Accessing Logs
Logs for the scheduler and all service nodes can be viewed from the DC/OS web interface.
- Scheduler logs are useful for determining why a node isn’t being launched (this is under the purview of the Scheduler).
- Node logs are useful for examining problems in the service itself.
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:
- Visit
to access the DC/OS web interface. - Navigate to
Services
and click on the service to be examined (defaultcassandra
). - 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
). - In the task details, click on the
Logs
tab to go into the log viewer. By default, you will seestdout
, butstderr
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:
- Visit
/mesos to view the Mesos UI. - Click the
Frameworks
tab in the upper left to get a list of services running in the cluster. - Navigate into the correct framework for your needs. The scheduler runs under
marathon
with a task name matching the service name (defaultPKGNAME
). Service nodes run under a framework whose name matches the service name (defaultPKGNAME
). - You should now see two lists of tasks.
Active Tasks
are tasks currently running, andCompleted Tasks
are tasks that have exited. Click theSandbox
link for the task you wish to examine. - The
Sandbox
view will list files namedstdout
andstderr
. Click the file names to view the files in the browser, or clickDownload
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.