[katello-devel] Approaches on Changeset Manipulation by multiple users

[Jesus Rodriguez]

> On 05/31/2011 02:25 PM, Partha Aji wrote:
> > Justin and I have been looking for a method for enabling multiple
> > users manipulate/update the same changeset simultaneously before
> > promoting it to the next environment. Main issue here is that the
> > updates made to the changeset should be transparent to both users.
> > Before promotion they should exactly know what is getting promoted.
> > Problem here is that when 2 users are updating the changeset at the
> > same time or the same user has the same page opened in 2 browser
> > windows and clicks promote, the last change wins. So to remedy this
> > 2 approaches were suggested
> >
> > 1) Polling based approach. Here, every 2 or 3 seconds a check will
> > be made to the server asking if the changeset changed at the server
> > (similar to how notifications behave) and the changset UI will auto
> > refresh if it changed. I guess the User will be given some notice
> > saying "the changeset has been changed, refreshing your promotion
> > tree and changset contents..."
> >
> > 2) Locking based approach. Only one user can change the changeset at
> > a time. So user kinda acquires a lock on changeset and modifies it
> > and unlocks it or unlocks on time out so that some other user can
> > work on it. Before deciding to promote.
[snip]

> I think locking it down to single user access would be prohibitively
> annoying for an end user. We should implement a polling mechanism but
> I
> wouldn't do it as often as 2-3 seconds, I'd increase it to something
> like 60-120 seconds to reduce the load on the Katello server. 2-3
> second polling is a bit much even if the API call is very minimal.
> That
> could scale to be something pretty bad if you have hundreds or
> thousands
> of users on the site.

Is there a way to notify the UI from the server without polling?
If not, +1 to lowering the polling interval.

jesus

-- 
jesus m. rodriguez          | jesusr at redhat.com
principal software engineer | irc: zeus
red hat systems management  | 919.754.4413 (w)
rhce # 805008586930012      | 919.623.0080 (c)
+---------------------------------------------+
|   "Those who cannot remember the past       |
|    are condemned to repeat it."             |
|                        -- George Santayana  |
+---------------------------------------------+