Disk Metrics

In addition to these base metrics, many aggregate metrics are available. If an entity type has parents defined, you can formulate all possible aggregate metrics using the formula base_metric_across_parents.

In addition, metrics for aggregate totals can be formed by adding the prefix total_ to the front of the metric name.

Use the type-ahead feature in the Cloudera Manager chart browser to find the exact aggregate metric name, in case the plural form does not end in "s".

For example, the following metric names may be valid for Disk:

• average_queue_length_across_clusters
• total_average_queue_length_across_clusters

Some metrics, such as alerts_rate, apply to nearly every metric context. Others only apply to a certain service or role.

For more information about metrics, see Cloudera Manager Metrics and Metric Aggregation.

Metric Name	Description	Unit	Parents	CDH Version
average_queue_length	The average queue length of the requests issued to the disk. This is the same as the 'avgqu-sz' measure from iostat.	ios	cluster, host, rack	n/a
average_request_size	The average size in sectors of the requests issued to the disk. This is the same as the 'avgrq-sz' measure from iostat.	sectors	cluster, host, rack	n/a
await_read_time	The average time for read requests issued to the disk to be served. This includes the time spent by the requests in queue and the time spent servicing them. This is the same as the 'r_await' measure from iostat.	ms	cluster, host, rack	n/a
await_time	The average time for requests issued to the disk to be served. This includes the time spent by the requests in queue and the time spent servicing them. This is the same as the 'await' measure from iostat.	ms	cluster, host, rack	n/a
await_write_time	The average time for write requests issued to the disk to be served. This includes the time spent by the requests in queue and the time spent servicing them. This is the same as the 'w_await' measure from iostat.	ms	cluster, host, rack	n/a
read_bytes_rate	The number of bytes read from the device	bytes per second	cluster, host, rack	n/a
read_ios_rate	The number of read I/O operations issued to the device	ios per second	cluster, host, rack	n/a
service_time	The average service time for requests issued to the disk. This is the same as the 'svctm' measure from iostat. Note the warning from iostat for this metric: Warning! Do not trust this field any more. This field will be removed in a future sysstat version.	ms	cluster, host, rack	n/a
utilization	The percentage of CPU time during which I/O requests were issued to the device. This is the same as the 'util' measure from iostat.	percent	cluster, host, rack	n/a
write_bytes_rate	The number of bytes written to the device	bytes per second	cluster, host, rack	n/a
write_ios_rate	The number of write I/O operations issued to the device	ios per second	cluster, host, rack	n/a