Re: git: 8c47d8f53854 - main - prometheus_sysctl_exporter: fix metric aliasing

On Tue, Apr 19, 2022 at 8:22 AM Mateusz Piotrowski <0mp@freebsd.org> wrote:
>
> On 19/04/2022 14:56, Alan Somers wrote:
> > The branch main has been updated by asomers:
> >
> > URL: https://cgit.FreeBSD.org/src/commit/?id=8c47d8f53854825d8e8591ccd06e32b2c798f81c
> >
> > commit 8c47d8f53854825d8e8591ccd06e32b2c798f81c
> > Author:     Alan Somers <asomers@FreeBSD.org>
> > AuthorDate: 2022-04-18 21:29:37 +0000
> > Commit:     Alan Somers <asomers@FreeBSD.org>
> > CommitDate: 2022-04-19 12:56:39 +0000
> >
> >      prometheus_sysctl_exporter: fix metric aliasing
> >
> >      When exporting sysctls to Prometheus, the exporter replaces "." with
> >      "_".  This caused several metrics to alias, confusing the Prometheus
> >      server.  Fix it by:
> >
> >      * Renaming the "tcp_log_bucket" UMA zone to "tcp_log_id_bucket".  Also,
> >        rename "tcp_log_node" to "tcp_log_id_node" for consistency.
> >
> >      * Not exporting sysctls with "(LEGACY)" in the description.  That is
> >        used by ZFS sysctls that have been replaced by others, many of which
> >        alias to the same Prometheus metric name (like "vfs.zfs.arc_max" and
> >        "vfs.zfs.arc.max").
> >
> >      PR:             259607
> >      Reported by:    delphij
> >      MFC after:      2 weeks
> >      Sponsored by:   Axcient
> >      Reviewed by:    delphij,rew,thj
> >      Differential Revision: https://reviews.freebsd.org/D34952
>
> This should definitely make it to release notes.
>
> Also, should we keep a log of these kind of changes in the history section of the manual pages? I
> find the history logs that systemd folks publish in their manual pages to be quite informative,
> e.g., https://www.man7.org/linux/man-pages//man7/systemd.net-naming-scheme.7.html
>
> Best,
>
> Mateusz

Do you think that the uma zone rename is too disruptive to MFC?