This change adds a new collector called "nfs" that parses the contents
of /proc/net/rpc/nfs and turns it into metrics. It can be used to
inspect the number of operations per type, but also to keep an eye on an
extraneous number of retransmissions, which may indicate connectivity
issues.
I've picked the name "nfs", as most operating systems use "nfs" for the
client component and "nfsd" as the server component. If we want to add
stats for the NFS server as well, we'd better call such a collector
"nfsd".
We seem to have a small number of Linux servers here that have lines in
/proc/mdstat that cannot be parsed by the node exporter, due to them
containing attributes that are not matched by the regular expression
("super 1.2").
Extend the regular expression to skip this data, just like we do for all
of the other status lines.
* Prefer device path based names over exported names
For some sensors (like coretemp) it is possible that multiple
instances exist, thus base the name on the device path and not on
the exported name.
* Update end-to-end test for dual socket machines
Explicitly have 2 coretemp instances with a symlink for the device
such that the hwmon collector must pick that name (or fail)
* Add Linux NUMA "numastat" metrics
Read the `numastat` metrics from /sys/devices/system/node/node* when reading NUMA meminfo metrics.
* Update end-to-end test output.
* Add `numastat` metrics as counters.
* Add tests for error conditions.
* Refactor meminfo numa metrics struct
* Refactor meminfoKey into a simple struct of metric data.
This makes it easier to pass slices of metrics around.
* Refactor tests.
* Fixup: Add suggested fixes.
* Fixup: More fixes
* Add another scanner.Err() return
* Add "_total" to counter metrics.
* Add hwmon support (mainly known from lm-sensors)
This commit adds initial support for linux hardware sensors, exported
through sysfs.
Details of the interface can be found at
https://www.kernel.org/doc/Documentation/hwmon/sysfs-interface
* Add end-to-end test with some real life data
* Cleanup comments on hwmon collector
* Drop raw sensor name from hwmon output
* Let the sensor label be "sensor"
* Add hwmon short description to README.
