[ClusterLabs] Antw: Re: fencing on iscsi device not working

[Ken Gaillot]

On Thu, 2019-11-07 at 07:43 +0000, Roger Zhou wrote:
> 
> On 11/7/19 1:55 AM, Andrei Borzenkov wrote:
> > 06.11.2019 18:55, Ken Gaillot пишет:
> > > On Wed, 2019-11-06 at 08:04 +0100, Ulrich Windl wrote:
> > > > > > > Ken Gaillot <kgaillot at redhat.com> schrieb am 05.11.2019
> > > > > > > um
> > > > > > > 16:05 in
> > > > 
> > > > Nachricht
> > > > <d2e2114a48ef66535e11fe2fe5970d2bd687c83d.camel at redhat.com>:
> > > > > Coincidentally, the documentation for the pcmk_host_check
> > > > > default
> > > > > was
> > > > > recently updated for the upcoming 2.0.3 release. Once the
> > > > > release
> > > > > is
> > > > > out, the online documentation will be regenerated, but here
> > > > > is the
> > > > > text:
> > > > > 
> > > > > Default
> > > > > ‑‑‑‑‑‑‑
> > > > > static‑list if either pcmk_host_list or pcmk_host_map is set,
> > > > > otherwise
> > > > > dynamic‑list if the fence device supports the list action,
> > > > > otherwise
> > > > > status if the fence device supports the status action,
> > > > > otherwise
> > > > > none
> > > > 
> > > > I'd make that an itemized list with four items. I thinks it
> > > > would be
> > > > easer to
> > > > understand.
> > > 
> > > Good idea; I edited it so that the default and description are
> > > combined:
> > > 
> > > How to determine which machines are controlled by the device.
> > > Allowed
> > > values:
> > > 
> > > * +static-list:+ check the +pcmk_host_list+ or +pcmk_host_map+
> > > attribute (this is the default if either one of those is set)
> > > 
> > > * +dynamic-list:+ query the device via the "list" command (this
> > > is
> > > otherwise the default if the fence device supports the list
> > > action)
> > > 
> > 
> > Oops, now it became even more ambiguous. What if both
> > pcmk_host_list is
> > set *and* device supports "list" (or "status") command? Previous
> > variant
> > at least was explicit about precedence.
> > 
> > "Otherwise" above is hard to attribute correctly. I really like
> > previous
> > version more.
> 
> +1
> 
> plus 2 cents:
> 
> I feel confused between Default and Assigned value if combine them
> in 
> the description as above. I prefer to keep them separate.
> 
> I guest Ken might want to keep Pacemaker_Explained DOC more readable
> at 
> the end of the day, ie. to avoid too many words in Default column
> [1]. 
> For that, might be we can do differently, like the mockup [2].
> 
> [1] 
> https://github.com/ClusterLabs/pacemaker/blob/d863971b7e0c56fbe6cc12815348e8e39b2e25c4/doc/Pacemaker_Explained/en-US/Ch-Fencing.txt#L182
> 
> [2]
> 
> > pcmk_host_check
> > string
> > +NOTE+
> 
> a|How to determine which machines are controlled by the device.
> 
> * +NOTE:+
>   The default value is static-list if either +pcmk_host_list+ or 
> +pcmk_host_map+ is set,
>   otherwise dynamic-list if the fence device supports the list
> action,
>   otherwise status if the fence device supports the status action,
>   otherwise none.
> 
>   Allowed values:
> 
> * +dynamic-list:+ query the device via the "list" command
> * +static-list:+ check the +pcmk_host_list+ or +pcmk_host_map+
> attribute
> * +status:+ query the device via the "status" command
> * +none:+ assume every device can fence every machine

Elaborating on that approach, how about:

Default: "The value appropriate to other configuration options and
device capabilities (see note below)"

Description unchanged

Note: "The default value for +pcmk_host_check+ is +static-list+ if
either +pcmk_host_list+ or +pcmk_host_map+ is configured. If neither of
those are configured, the default is +dynamic-list+ if the fence device
supports the list action, or +status+ if the fence device supports the
status action but not the list action. If none of those conditions
apply, the default is +none+."

> 
> Cheers,
> Roger
> 
> > 
> > > * +status:+ query the device via the "status" command (this is
> > > otherwise the default if the fence device supports the status
> > > action)
> > > 
> > > * +none:+ assume every device can fence every machine (this is
> > > otherwise the default)
-- 
Ken Gaillot <kgaillot at redhat.com>