Node-exporter statistics

In the output of ad-hoc or snapshot-diff mode, if node-exporter is installed on the YugabyteDB cluster, the last group of statistics that are shown are the node-exporter statistics. The captured statistics are essentially a statistic name and a statistic value. The values to be displayed are ordered by hostname, metric_type and metric_name.

By default, counter values are shown, for which the value is the difference between the end and begin values.

• If a counter is zero during both the begin and end snapshot, the statistic is skipped.
• If a counter is non-zero and existing in the end snapshot, and the statistic is not existing in the begin snapshot, the end snapshot value is taken as value.
• If a counter is non-zero and existing in the begin snapshot, and not existing in the end snapshot, the value is skipped.
• If a counter is non-zero in the begin and end snapshots, but subtracting leads to zero, then the statistic is not printed. Supposedly nothing happened, but previously something happened.
• If a counter is non-zero in the begin and end snapshots, but the end value is lower than the begin value: this is a suspicious situation. Currently the resulting negative value is shown.

This is how node-exporter statistics output looks like:

192.168.66.80:9300   counter  node_context_switches_total                                                       7759.000000         862.111 /s
192.168.66.80:9300   counter  node_cpu_seconds_total_idle                                                          8.150000           0.906 /s
192.168.66.80:9300   counter  node_cpu_seconds_total_irq                                                           0.310000           0.034 /s
192.168.66.80:9300   counter  node_cpu_seconds_total_softirq                                                       0.120000           0.013 /s
192.168.66.80:9300   counter  node_cpu_seconds_total_system                                                        0.170000           0.019 /s
192.168.66.80:9300   counter  node_cpu_seconds_total_user                                                          0.010000           0.001 /s

Explanation:

gauges

If the --gauges enable switch is used, gauge type values are shown alongside counter values.

• If a gauge is zero during both the begin and end snapshot, the statistic is skipped.
• If a gauge is non-zero and existing in the end snapshot, and the statistic is not existing in the begin snapshot, the end snapshot value is taken as value.
• If a gauge is non-zero and existing in the begin snapshot, and not existing in the end snapshot, the value is skipped.
• if a gauge is non-zero in the begin and end snapshots, and subtracting leads to zero, the value is printed(!).

This is what this looks like:

192.168.66.80:9300   gauge    node_arp_entries_eth0                                                                2.000000              +0
192.168.66.80:9300   gauge    node_arp_entries_eth1                                                                3.000000              +0
192.168.66.80:9300   gauge    node_boot_time_seconds                                                      1666174770.000000              +0
192.168.66.80:9300   counter  node_context_switches_total                                                        994.000000         994.000 /s
192.168.66.80:9300   gauge    node_cooling_device_max_state_1_intel_powerclamp                                    50.000000              +0

Explanation: