I'm currently working on writing a metrics exporter for the Prometheus
monitoring system to provide access to sysctl metrics. Prometheus and
sysctl have some structural differences:
- sysctl is a tree of string component names.
- Prometheus uses a flat namespace for its metrics, but allows you to
attach labels with values to them, so that you can do aggregation.
An initial version of my exporter simply translated
hw.acpi.thermal.tz1.temperature
to
sysctl_hw_acpi_thermal_tz1_temperature_celcius
while we should ideally have
sysctl_hw_acpi_thermal_temperature_celcius{thermal_zone="tz1"}
allowing you to graph all thermal zones on a system in one go.
The change presented in this commit adds support for accomplishing this,
by providing the ability to attach labels to nodes. In the example I
gave above, the label "thermal_zone" would be attached to "tz1". As this
is a feature that will only be used very rarely, I decided to not change
the KPI too aggressively.
Discussed on: hackers@
Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D8775
Add S8, S16, S32, and U32 types; add SYSCTL*() macros for them, as well
as for the existing 64-bit types. (While SYSCTL*QUAD and UQUAD macros
already exist, they do not take the same sort of 'val' parameter that
the other macros do.)
Clean up the documented "types" in the sysctl.9 document. (These are
macros and thus not real types, but the manual page documents intent.)
The sysctl_add_oid(9) arg2 has been bumped from intptr_t to intmax_t to
accommodate 64-bit types on 32-bit pointer architectures.
This is just the kernel support piece; the userspace sysctl(1) support
will follow in a later patch.
Submitted by: Ravi Pokala <rpokala@panasas.com>
Reviewed by: cem
Relnotes: no
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D4091
SYSCTL code. Added description of new macros and functions.
- Merged dynamic and static SYSCTL related content into a single
manual page, hence parameters and functionality is very much the same.
- Uppercased all occurrences of "OID".
- Updated all SYSCTL examples.
PR: 192101
- Clarify that exactly one of the "access" flags is required and
list the optional flags in a separate list. Prefer bundling
CTLFLAG_TUN into the access flag by not documenting it as an
optional flag to set.
Approved by: re (glebius)
MFC after: 1 week
It's a bit more pedantic regarding .Bl list elements. This has an added
benefit of unbreaking the ipfw(8) manpage, where groff was silently
skipping one list element.
pages existed only for the dynamic sysctl interfaces. There's probably
more complete and accurate content, better advice, etc, that could be added
here.
Per scottl's suggest, add a small piece of moralizing text regarding the
fact that sysctl names quickly get embedded in system configuration files,
libraries, third party applications, and even books, so renaming and
removing names after they've been published is a tricky issue.
MFC after: 1 month
cd src/share; find man[1-9] -type f|xargs perl -pi -e 's/[ \t]+$//'
BTW, what editors are the culprits? I'm using vim and it shows
me whitespace at EOL in troff files with a thick blue block...
Reviewed by: Silence from cvs diff -b
MFC after: 7 days
whitespace changes, which should not be a problem because this
is only the second revision of the file and translators are
unlikely to have gotten started yet.
Reviewed by: abial
and remove sysctl oids at will during runtime - they don't rely on
linker sets. Also, the node oids can be referenced by more than
one kernel user, which means that it's possible to create partially
overlapping trees.
Add sysctl contexts to help programmers manage multiple dynamic
oids in convenient way.
Please see the manpages for detailed discussion, and example module
for typical use.
This work is based on ideas and code snippets coming from many
people, among them: Arun Sharma, Jonathan Lemon, Doug Rabson,
Brian Feldman, Kelly Yancey, Poul-Henning Kamp and others. I'd like
to specially thank Brian Feldman for detailed review and style
fixes.
PR: kern/16928
Reviewed by: dfr, green, phk
