The Weka system has some internal/external asynchronous operations and maintenance tasks, such as migrating an object store and downloading/uploading snapshots. These tasks are performed in the background and should not interfere nor starve the Weka system from serving IOs with high performance.
The Weka system limits the CPU resources these tasks consume to 5% per host CPU.
Note: When the CPU is idle, background tasks can use more than the configured resources, but they are immediately freed if needed for serving IOs.
Note: The configured limit affects both external tasks (that are visible using the GUI/CLI) and internal low priority asynchronous operations.
It is possible to view currently-running background tasks, including their status and progress.
Command: weka cluster tasks
This command is used for viewing all background tasks. For each task, a range of data can be displayed, as shown in the following example:
# weka cluster tasksType | State | Progress | Description-----------+---------+----------+-----------------------------------------------------------OBS_DETACH | RUNNING | 94 | Detaching Object Storage `obs_1` from filesystem `default`
It is possible to limit the resources being used by background tasks.
Command: weka cluster tasks limits
This command is used to view the currently-defined limits.
Command: weka cluster tasks limits set <cpu-limit cpu-limit>
This command is used to update the CPU limit.