Re: [ovirt-devel] Gluster Volume Snapshots - Feature review

[Shubhendu Tripathi]

On 01/01/2015 10:36 PM, Einav Cohen wrote:
----- Original Message -----
From: "Shubhendu Tripathi" <shtri...@redhat.com>
Sent: Thursday, January 1, 2015 10:05:48 AM
On 12/31/2014 11:42 PM, Einav Cohen wrote:
Thanks, Shubhendu. Additional comments:

...
Yes, attempt to create second snapshot schedule is actually an override
option. Of course spot creation is allowed in addition to the scheduled.
...
...
If the option Volumes -> Snapshots -> New selected, the dialog opens
with pre-populated snapshot name prefix and Recurrence type selected as
None by default. This effectively is one time snapshot creation.
If this is first time and user wants to schedule the snapshot creation,
he/she can change the recurrence type and provide details. Snapshot
creation is scheduled in this case.
Later, it user wants to edit the schedule, he/she needs to select option
Volumes -> Snapshots -> Schedule (may be for this reason only I want to
call it Edit Schedule). So effectively option Volumes -> Snapshots ->
Schedule is meant for only re-scheduling the snapshot creation. If its
not yet scheduled dialog opens with recurrence type selected as None.
...
  From your latest responses, I conclude the following.

via the "New" dialog, you can:

(1) create a one-time snapshot
(2) create a new snapshot schedule
(3) override (and practically, edit) an existing snapshot schedule

via the "Schedule" dialog, you can:

(a) create a one-time snapshot (by selecting the 'None' recurrence)
(b) create a new snapshot schedule (by selecting something other than
'None' in the recurrence field, given that no schedule exists yet)
(c) edit an existing snapshot schedule (which is what this dialog is
actually meant to do).

I am not sure about (a), but it doesn't matter much for my point: "New"
and "Schedule" have the exact same functionality. To be more accurate:
"New" contains all of the needed functionality; "Schedule" is not really
needed. The only thing that "New" is potentially missing is showing the
values of the already-existing snapshot schedule, if one exists.

I think that this may confuse to the user; I recommend to either
unite both of these actions/dialogs to a single action/dialog, or
separate completely some functionalists.

So my recommendation is to do one of the following:

(a) unite:
Have a single action ("Create / Schedule") which will display a
dialog very similar to the "New" dialog, with the option to see the
values of the already-existing snapshot schedule, if one exists.
In this case, I would actually recommend to go with something more
similar to option 2 in http://i.imgur.com/4j7hvRY.png, rather than
option 3 (so the separation between *creating new* *one-time*
snapshot and *editing an existing* *scheduled* snapshot is clearer).
see http://i.imgur.com/ZgCp9Tz.png for an updated suggestion.

- or -

(b) separate:
Have two completely separate actions: "Create Now" and "Schedule".

- The "Create Now" dialog will look like the 'General' side-section
of the "New" dialog (i.e. without the "Schedule" side-section;
it will allow only one-time immediate snapshot creation.

- The "Schedule" dialog will look like the "New" dialog (with both
'General' and 'Schedule' side-sections) without the "None" recurrence,
and will allow only creating a new recurring snapshot schedule (if one
doesn't exist yet) or editing the existing schedule (in this case, the
dialog would be pre-populated with the values of the existing schedule).

I am more in favor of (b) - it seems simpler and more user-friendly in
my view.
Option (b) is something which we had started with, then at later stage
it was discussed that scheduling as well should be in the flow of
creation of snapshot so merged with New Snapshot option. After this as
we need Edit option for snapshot schedule, so introduced Schedule option.

But still, as you suggest I feel option (b) is no doubt a clearer and
user friendly way.

Alok, need a point of view from PMs on this.
Thanks, Shubhendu.

@Alok (and all):
the main pain-point in the current design that I am trying to address is
the fact that in the 'New' dialog, you have the option to create a one-
time snapshot, and within the same dialog, with a very small (too small
IMO) change, you have the option to edit (override) an already-existing
schedule, without even realizing necessarily that you are editing
something (since you are in a 'New' dialog) and without seeing the values
of the object that you are editing. From a UX perspective, this may be
confusing and misleading.

if it is imperative to combine the one-time creation functionality with
the scheduling functionality, you have option (a).

here is another option (c) that will allow you to create a one-time
snapshot and *create* a new schedule in the same dialog.
it is also probably the closest option to the original design in the
wiki, so I encourage you to consider it:

(c) Have two options, "New" and "Schedule", like today.

- "New" will be *only* for creating new objects, not editing/overriding
existing ones. It will look very similar to "New" in the current design,
including the "None" recurrence that I have suggested before.

  * In case a schedule doesn't exist yet - "New" will have both the
'General' and 'Schedule' sections, like today, allowing creating a one-
time snapshot as well as creating a new snapshot schedule.

  * In case a schedule already exists - "New" will have only the 'General'
side-section (the 'Schedule' side-section will not be displayed), allowing
only creation of new one-time snapshots.

- "Schedule":

  * In case a schedule doesn't exist yet - two options:

     i.  disable this button (i.e. force the user to create a new schedule
via "New"); in this case, I agree with Shubhendu on renaming the button to
"Edit Schedule".

    - or -

     ii. have the dialog look exactly like "New" today, without the "None"
recurrence option; so only new schedule can be created, not one-time
snapshots. One-time snapshots should be created only via "New".

  * In case a schedule already exists - the dialog will look like "New",
without the 'General' section (i.e. very similar to the mock-up of the
"Schedule" dialog in the ovirt wiki today), pre-populated with the current
values of the existing schedule.

Your thoughts/comments are welcome. Thank you.

So if we go ahead with above mentioned option (c) with "Edit Schedule" 
option it would be something as below.

- Have two optiona "New" and "Edit Schedule" under Volumes -> Snapshots.

- "New" will be *only* for creating new objects, not editing/overriding
existing ones.

 * In case a schedule doesn't exist yet - "New" will have both the
'General' and 'Schedule' sections, like today, allowing creating a one-
time snapshot as well as creating a new snapshot schedule.

 * In case a schedule already exists - "New" will have only the 'General'
side-section (the 'Schedule' side-section will not be displayed), allowing
only creation of new one-time snapshots.

- "Edit Schedule":

 * In case a schedule doesn't exist yet - disable this button (i.e. force the 
user to create a new schedule
via "New")

 * In case a schedule already exists - the dialog will look like "New",
without the 'General' section (i.e. very similar to the mock-up of the
"Schedule" dialog in the ovirt wiki today), pre-populated with the current
values of the existing schedule.

@Alok, need your confirmation. This option certainly looks clean to me 
personally but leave the final call to your descretion.

Regards,
Shubhendu



Your comments/thoughts are welcome.

Thanks!

----
Regards,
Einav

----- Original Message -----
From: "Shubhendu Tripathi" <shtri...@redhat.com>
To: "Einav Cohen" <eco...@redhat.com>
Cc: de...@linode01.ovirt.org, "rhsc-dev" <rhsc-...@redhat.com>
Sent: Wednesday, December 31, 2014 12:56:44 AM
Subject: Re: [ovirt-devel] Gluster Volume Snapshots - Feature review

Hi Einav,

Find the comments inline.

Thanks and Regards,
Shubhendu

On 12/30/2014 11:13 PM, Einav Cohen wrote:
Thank you, Shubhendu! I have a few more comments:

Yes that's true for most of the cases. But having Options setting from
sub-tab, not sure if that's correct. May be "New" is fine.
I think that if a user already got to the "Snapshots" sub-tab of a
specific Volume, it would seem strange that not all Snapshots-related
actions for that Volume are available from there - but I will leave it
to your discretion; I think that "New" is indeed the most important one
to have also in the sub-tab.
We may have the New option available under sub tab as well. Setting
configuration options would only be available in Volumes main tab.

Once scheduled the only way to stop snapshot creation is to provide an
end date.
let me try and understand what are the exact snapshot creation
capabilities.
consider the following use-cases (which may make absolutely no sense,
just giving these as examples in order to understand the capabilities):

(1) let's say that I want to do two recurring snapshots schedules in
parallel for a single volume: one Monthly, and another one Weekly.
Can I do that?
We can have only one schedule for a volume at a time.

I am assuming that I can't, i.e. there can only be one
recurring-snapshot-
creation schedule per volume (which you create via "New" and edit via
"Schedule") - is that correct? If so: are you blocking an attempt to
create a "New" recurring snapshot schedule when one already exists for
this Volume (e.g. disable the "New" button, fail a CanDoAction with a
message such as "Cannot create snapshot scheduling. A snapshot scheduling
already exists for this Volume", etc.) or allowing override of the
already-
existing schedule (with a proper warning)?
Even if a volume snapshot creation is scheduled user can still opt for
onetime spot snapshot creation and New would be available.

If my assumption is wrong, and I can have two (or more) recurring-
snapshot-creation schedules per volume: how do I *edit* these schedules?
what happens when I click on "Schedule"? which one of the two schedules
will I edit? The Weekly one? The Monthly one?
As there is only one schedule for a volume at a time, so this is not
valid scenario. Exiting single instance of schedule can be edited using
the option Volumes -> Snapshots -> Schedule. May be if you suggest this
option can be renamed to "Edit Schedule".

If I am comparing the terminology to the one of Calendar meeting schedule
(see http://i.imgur.com/xvf5w30.png): I don't have any "series" objects
that I can 'edit', I can see only "instances", and I can edit only one
"global" 'series' object via the "Schedule" button.
[again: if there can only be one recurring-snapshot-creation schedule per
volume, then the current design is OK, assuming the attempt to create a
second snapshot-schedule for a volume is properly blocked/overridden/...]
Yes, attempt to create second snapshot schedule is actually an override
option. Of course spot creation is allowed in addition to the scheduled.

(2) let's say that I want to do a weekly recurring snapshot scheduling
for
a certain volume. In addition to that weekly recurring snapshots, I want
to take a one-time snapshot of this volume right now. Can I do that?
Yes, as discussed above stop one time creation in addition to the
scheduled is allowed.

If so: then my suggestion [http://i.imgur.com/4j7hvRY.png, option 3] is
indeed valid; I am assuming that the user can create, per volume: one
recurring snapshot schedule + unlimited one-time snapshots.
Yes. That's correct.

[If the user can create two (or more) recurring snapshot schedules - see
(1) above].
need to make sure that the user is able to create a "New" snapshot with
the "Weekly" recurrence schedule, and then another "New" snapshot(s) with
the "None" recurrence schedule, which will create the one-time
snapshot(s)
immediately, and that the schedule of the Weekly snapshot can be edited
via the "Schedule" option.
So it goes like this. Say a Weekly snapshot is scheduled for certain
volume and later user wants to create single on-spot snapshot. For this
he/she need to select the option Volumes -> Snapshots -> New and not
Volumes -> Snapshots -> Schedule. By default the option None is selected
as Recurrence type and it creates a one time snapshot. Still the
schedule stands valid in the system and if the user wants to edit the
schedule he/she need to select the option Volumes -> Snapshots ->
Schedule. Hope this clarifies.

If not (i.e. the user can create only one recurring snapshot schedule,
and that's it - no additional recurring snapshot schedules, no one-time
immediate snapshots, etc.), then my suggestion is invalid, and a 'None'
recurrence is not needed.
As said above, one time snapshot creation is still allowed in addition
to the scheduled. (Using Volumes -> Snapshots -> New option)

In this case, just need to make sure that the 'Schedule' side-section of
the dialog will be pre-populated with the most common/reasonable
recurrence
schedule, in case the user will not touch it.
BTW, if this is indeed the case, then there is probably no need for both
'New' and 'Schedule' buttons - only 'Schedule' is sufficient.

Accept. The snapshot create dialog itself can be used here.
Just need to make sure to change its title accordingly (to 'Schedule
Snapshot' or something similar; right now it says "New Snapshot" in
the wiki).

I assume that this dialog can be used for:

(a) creating a New snapshot schedule (which should look very similar
to the 'New Snapshot' dialog, maybe with some pre-populated values,
maybe without the 'None' option in the Recurrence drop-down).
If the option Volumes -> Snapshots -> New selected, the dialog opens
with pre-populated snapshot name prefix and Recurrence type selected as
None by default. This effectively is one time snapshot creation.
If this is first time and user wants to schedule the snapshot creation,
he/she can change the recurrence type and provide details. Snapshot
creation is scheduled in this case.
Later, it user wants to edit the schedule, he/she needs to select option
Volumes -> Snapshots -> Schedule (may be for this reason only I want to
call it Edit Schedule). So effectively option Volumes -> Snapshots ->
Schedule is meant for only re-scheduling the snapshot creation. If its
not yet scheduled dialog opens with recurrence type selected as None.

- and/or -

(b) editing the already-existing schedule (in this case, fields that
cannot be edited should be disabled).
As above.

I hope I was clear - please let me know if you have any questions or
comments.

Thanks again!

----
Regards,
Einav

----- Original Message -----
From: "Shubhendu Tripathi" <shtri...@redhat.com>
To: "Einav Cohen" <eco...@redhat.com>
Cc: de...@linode01.ovirt.org, "rhsc-dev" <rhsc-...@redhat.com>
Sent: Tuesday, December 30, 2014 7:09:51 AM
Subject: Re: [ovirt-devel] Gluster Volume Snapshots - Feature review

Thanks Einav for the detailed review and your comments.
Find below the comment inline.

Will update the wiki accordingly and circulate.

Team, please provide your thoughts (if conflicting) on this.

Thanks and Regards,
Shubhendu

On 12/30/2014 05:33 AM, Einav Cohen wrote:
Hi Shubhendu,

First of all - very detailed wiki pages (I focused mainly on the
User Experience part) - nicely done.

I have a couple of comments / suggestions regarding the GUI:

Snapshot action-group:

- from the wiki page:
"""
A new action-group "Snapshot" would be introduced under actions
for a volume.
"""
I assume that you will implement it similarly to the "Power Management"
action-group (on Hosts main tab) or the "Profiling" action-group (on
the Volumes tab), i.e. with a drop-down-like styling
[http://i.imgur.com/eWRg6o8.png]?
Yes. That's correct.

- If the Snapshot-related actions are expected to be core/critical in
the Volumes-related workflows, it makes sense to put them in the main-
tab, but please consider adding them to the Snapshots sub-tab as well,
in order to be consistent with other similar oVirt workflows.
Yes that's true for most of the cases. But having Options setting from
sub-tab, not sure if that's correct. May be "New" is fine.

New Snapshot dialog -> Schedule section:

- I suggest to implement the time-interval selection with a drop-down,
rather than a radio-button group; it is more consistent with e.g.
event-repeat scheduling in a calendar [http://i.imgur.com/y9Gn3wq.png],
it will save real-estate within the dialog and it will be more easily
readable for the user.
That's a good suggestion. Will do this.

- to my understanding, the New Snapshot functionality doesn't have to
be recurrent; however, there isn't any way to "disable" the recurring
aspect. Here are some suggestions to how this should be added:
http://i.imgur.com/4j7hvRY.png
Once scheduled the only way to stop snapshot creation is to provide an
end date.

Option 3 is my personal favorite - it is the simplest, and is
consistent
with Calendear-scheduling UI. Option 1 is my least favorite, however it
is consistent with e.g. the "Enable Power Management" UI within the
"New
Host" dialog.
Option-3 looks good to me as well. Should be doable I feel.

Snapshots -> Options:

- I think that there are a couple of problematic issues with this
dialog:

      * the different functionality of this dialog when a Volume is
      selected
vs. when no Volume is selected may be unclear to the user.
Agree

      
      * the fact that we can update Cluster-related parameters (which
potentially affects *all* volumes in that Cluster) within a specific
Volume-context dialog is a bit risky - and we don't have anything
similar
to that anywhere in the application today IIRC.

my recommendations:

      * have separate "Options - Cluster" and "Options - Volume"
      actions;
"Options - Cluster" should always be enabled.
"Options - Volume" should be enabled only when a Volume is selected.
Accept

      * Seehttp://i.imgur.com/pfRpjrH.png  for my suggestion for
      "Cluster
Options" vs. "Volume Options". Note that from the "Volume Options"
dialog, you may allow editing the Cluster Options by clicking on the
link-button, which will either (a) open the "Cluster Options" dialog
on top or (b) allow editing the Cluster Values inline within the
already-open dialog - this should be accompanied with a clear note to
the user that he is editing Cluster-related parameters from the current
(Volume) context, which may affect *all* Volumes in that Cluster.
Also note that in my suggestion, the user can conveniently see both the
Volume values and the Cluster Values side-by-side at once, for
reference.
Accept

Snapshots -> Schedule:

- to my understanding, this should be very similar (or identical) to
the
New Snapshot functionality? if so, we may want to simply open the "New
Snapshot" dialog focused on the "Schedule" side-section (rather than
the
'General' side-section, maybe already pre-populated with some values in
the 'General' side-section (which will still be editable by the user)
and
something already pre-selected in the (focused) "Schedule" section.

please let me know whether you think these can/should be incorporated
into the design, and/or if you have any comments or questions.
Accept. The snapshot create dialog itself can be used here.

thanks.

----
Regards,
Einav

----- Original Message -----
From: "Shubhendu Tripathi"<shtri...@redhat.com>
To:de...@linode01.ovirt.org,jhern...@redhat.com, "Michael
Pasternak"<mpast...@redhat.com>
Sent: Monday, November 10, 2014 1:52:40 AM
Subject: [ovirt-devel] Gluster Volume Snapshots - Feature review

Hi All,

Please help us to review the design of Gluster Volume Snapshots in
oVirt,

Here are two design on wiki page

General Feature Design
http://www.ovirt.org/Features/GlusterVolumeSnapshots

Detailed Design
http://www.ovirt.org/Features/Design/GlusterVolumeSnapshots

We target it in ovirt 3.6 release.

Marked Juan/Michael specifically for REST review.

Best Regards,
Shubhendu Tripathi
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