Monitoring Node Metrics
You can examine fine-grained analytics information about the nodes in your cluster by using
the Node Metrics API
with the maprcli
command-line tool. You can use this information to
examine specific aspects of your node's performance at a very granular level. The
node metrics
API returns data as a table sent to your terminal's
standard output or as a JSON file. The JSON file includes in-depth reports on the activity
on each CPU, disk partition, and network interface in your node.
Node metrics cover the following general categories:
- CPU time used
- Memory used
- RPC activity
- Process activity
- Storage used
- TaskTracker resources used
The hoststats
service writes raw metrics data to the
/var/mapr/local/<hostname>/metrics
volumes as hourly files. The
files rotate as specified by the metric.file.rotate
parameter in the db.conf file.
The Metrics database holds data in the following tables:
- METRIC_TRANSACTION: Data is written every 10 seconds and partitioned by day. This table retains up to three days of data.
- METRIC_TRANSACTION_EVENT: Holds data regarding system events such as service starts/stops and disk additions.
- METRIC_TRANSACTION_SUMMARY_DAILY: Holds the aggregate, maximum, and minimum values for five-minute intervals of the data in the METRIC_TRANSACTION table. This table is partitioned by day and holds up to 15 days' worth of data.
- METRIC_TRANSACTION_SUMMARY_YEARLY: Holds the aggregate, maximum, and minimum values for daily intervals of the data in the METRIC_TRANSACTION_SUMMARY_DAILY table. This table is partitioned by year and holds up to 100 years' worth of data.