Similar counts are exposed via Prometheus.
This adds the one that are perceived by etcd server.
e.g.
os_fd_limit 120000
os_fd_used 14
process_cpu_seconds_total 0.31
process_max_fds 120000
process_open_fds 17
Signed-off-by: Gyuho Lee <leegyuho@amazon.com>
{"level":"warn","ts":1527101858.6985068,"caller":"etcdserver/util.go:115","msg":"apply request took too long","took":0.114101529,"expected-duration":0.1,"prefix":"","request":"header:<ID:1029181977902852337> put:<key:\"\\000\\000...
Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
{"level":"warn","ts":1527101858.4149103,"caller":"etcdserver/raft.go:370","msg":"failed to send out heartbeat; took too long, server is overloaded likely from slow disk","heartbeat-interval":0.1,"expected-duration":0.2,"exceeded-duration":0.025771662}
{"level":"warn","ts":1527101858.4149644,"caller":"etcdserver/raft.go:370","msg":"failed to send out heartbeat; took too long, server is overloaded likely from slow disk","heartbeat-interval":0.1,"expected-duration":0.2,"exceeded-duration":0.034015766}
Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
The _total suffix is by convention for counters,
don't use it on a gauge. Clarify help string.
Tweak metric name so it'll sort with related metrics,
and be a little more understandable.
Remove open file descriptor metric, as Prometheus client_golang
provides that out of the box as process_open_fds which is also
more up to date. Both only support Linux, so there's no loss of
platform support.
Fixes#5229
Fix#2841.
From Prometheus developer:
```
the recommended way for etcd as an open source project and under
consideration of its size would be etcd_<subsystem>_<name>.
```
We made the naming change accordingly.
It exposes the metrics of file descriptor limit and file descriptor used.
Moreover, it prints out warning when more than 80% of fd limit has been used.
```
2015/04/08 01:26:19 etcdserver: 80% of the file descriptor limit is open
[open = 969, limit = 1024]
```
