System Stats Monitor is a problem daemon in node problem detector. It collects pre-defined health-related metrics from different system components. Each component may allow further detailed configurations.

Currently supported components are:

cpu
disk
host
memory

See example config file here.

By setting the metricsConfigs field and displayName field (example), you can specify the list of metrics to be collected, and their display names on the Prometheus scaping endpoint.

Detailed Configuration Options

Global Configurations

Data collection period can be specified globally in the config file, see invokeInterval at the example.

CPU

Below metrics are collected from cpu component:

cpu_runnable_task_count: The average number of runnable tasks in the run-queue during the last minute. Collected from /proc/loadavg.
cpu_usage_time: CPU usage, in seconds. The CPU state for the corresponding usage is reported under the state metric label (e.g. user, nice, system...).

Disk

Below metrics are collected from disk component:

disk_io_time: # of milliseconds spent doing I/Os on this device
disk_weighted_io: # of milliseconds spent doing I/Os on this device
disk_avg_queue_len: average # of requests that was waiting in queue or being serviced during the last invokeInterval
disk_operation_count: # of reads/writes completed
disk_merged_operation_count: # of reads/writes merged
disk_operation_bytes_count: # of Bytes used for reads/writes on this device
disk_operation_time: # of milliseconds spent reading/writing
disk_bytes_used: Disk usage in Bytes. The usage state is reported under the state metric label (e.g. used, free). Summing values of all states yields the disk size.

The name of the disk block device is reported in the device_name metric label (e.g. sda).

For the metrics that separates read/write operations, the IO direction is reported in the direction metric label (e.g. read, write).

And a few other options:

includeRootBlk: When set to true, add all block devices that's not a slave or holder device to the list of disks that System Stats Monitor collects metrics from. When set to false, do not modify the list of disks that System Stats Monitor collects metrics from.
includeAllAttachedBlk: When set to true, add all currently attached block devices to the list of disks that System Stats Monitor collects metrics from. When set to false, do not modify the list of disks that System Stats Monitor collects metrics from.
lsblkTimeout: System Stats Monitor uses lsblk to retrieve block devices information. This option sets the timeout for calling lsblk commands.

Host

Below metrics are collected from host component:

host_uptime: The uptime of the operating system, in seconds. OS version and kernel versions are reported under the os_version and kernel_version metric label (e.g. cos 73-11647.217.0, 4.14.127+).

Memory

Below metrics are collected from memory component:

memory_bytes_used: Memory usage by each memory state, in Bytes. The memory state is reported under the state metric label (e.g. free, used, buffered...). Summing values of all states yields the total memory of the node.
memory_anonymous_used: Anonymous memory usage, in Bytes. Memory usage state is reported under the state metric label (e.g. active, inactive). active means the memory has been used more recently and usually not swapped until needed. Summing values of all states yields the total anonymous memory used.
memory_page_cache_used: Page cache memory usage, in Bytes. Memory usage state is reported under the state metric label (e.g. active, inactive). active means the memory has been used more recently and usually not reclaimed until needed. Summing values of all states yields the total page cache memory used.
memory_unevictable_used: Unevictable memory usage, in Bytes.
memory_dirty_used: Dirty pages usage, in Bytes. Memory usage state is reported under the state metric label (e.g. dirty, writeback). dirty means the memory is waiting to be written back to disk, and writeback means the memory is actively being written back to disk.