--gauges-enable
The default output for metrics shows the values of metrics of the type counter. Counters are ever increasing values. In most cases, a counter value on itself is not that useful, but the difference between two points in time is. That is the reason metrics requires two snapshots: to have the ability to calculate the difference, and thus understand how much a counter has changed.
But, there are also metrics that show absolute values, for which the value is not ever increasing, but instead just shows the current situation. This means that the difference between two points in time does not provide the same meaning as for a counter. The difference between the two points in time for absolute values can still be important. Such as value is called a gauge.
By default, yb_stats does NOT show gauge values. To make yb_stats show gauge values additional to the counters, is using the --gauges-enable switch.
This is yb_stats in ad-hoc mode (not showing gauges):
yb_stats
Begin metrics snapshot created, press enter to create end snapshot for difference calculation.
Time between snapshots: 1.019 seconds
192.168.66.80:12000 server cpu_stime 2 ms 2.200 /s
192.168.66.80:12000 server cpu_utime 13 ms 14.301 /s
192.168.66.80:12000 server server_uptime_ms 910 ms 1001.100 /s
192.168.66.80:12000 server voluntary_context_switches 233 csws 256.326 /s
This is yb_stats in ad-hoc mode showing gauges:
yb_stats --gauges-enable
Begin metrics snapshot created, press enter to create end snapshot for difference calculation.
Time between snapshots: 1.053 seconds
192.168.66.80:12000 server cpu_stime 2 ms 1.927 /s
192.168.66.80:12000 server cpu_utime 13 ms 12.524 /s
192.168.66.80:12000 server generic_current_allocated_bytes 26914872 bytes +1120
192.168.66.80:12000 server generic_heap_size 43188224 bytes +0
192.168.66.80:12000 server hybrid_clock_error 500000 us +0
192.168.66.80:12000 server hybrid_clock_hybrid_time 6824678428388270080 us +4253745152
192.168.66.80:12000 server server_uptime_ms 1038 ms 1000.000 /s
192.168.66.80:12000 server tcmalloc_current_total_thread_cache_bytes 2560384 bytes +137976
192.168.66.80:12000 server tcmalloc_max_total_thread_cache_bytes 33554432 bytes +0
192.168.66.80:12000 server tcmalloc_pageheap_free_bytes 3579904 bytes -90112
192.168.66.80:12000 server tcmalloc_pageheap_unmapped_bytes 7847936 bytes -8192
192.168.66.80:12000 server threads_running 45 threads +0
192.168.66.80:12000 server threads_running_CQLServer_reactor 1 threads +0
192.168.66.80:12000 server threads_running_acceptor 1 threads +0
192.168.66.80:12000 server threads_running_iotp_CQLServer 4 threads +0
192.168.66.80:12000 server threads_running_rpc_thread_pool 15 threads +0
192.168.66.80:12000 server voluntary_context_switches 294 csws 283.237 /s
The gauge values can be spotted because they do not end with '/s', because they do not show its value per second. Instead, the first value is the value of the END snapshot, and the second value is the difference with the FIRST snapshot.