[Engine-devel] Gluster Volume asynchronous tasks

[Sahina Bose]

On 08/12/2013 03:28 PM, Yair Zaslavsky wrote:
>
> ----- Original Message -----
>> From: "Sahina Bose" <sabose at redhat.com>
>> To: "Eli Mesika" <emesika at redhat.com>
>> Cc: "engine-devel" <engine-devel at ovirt.org>, arch at ovirt.org
>> Sent: Monday, August 12, 2013 11:51:15 AM
>> Subject: Re: [Engine-devel] Gluster Volume asynchronous tasks
>>
>>
>> On 08/12/2013 01:21 PM, Eli Mesika wrote:
>>> ----- Original Message -----
>>>> From: "Sahina Bose" <sabose at redhat.com>
>>>> To: "engine-devel" <engine-devel at ovirt.org>, arch at ovirt.org, "Michael
>>>> Pasternak" <mpastern at redhat.com>
>>>> Sent: Monday, August 12, 2013 8:41:55 AM
>>>> Subject: [Engine-devel] Gluster Volume asynchronous tasks
>>>>
>>>> Hi all,
>>>>
>>>> We are working on a feature to add support to start and monitor gluster
>>>> volume asynchronous tasks (like rebalancing a gluster volume, removing
>>>> brick from volume ) from the oVirt engine.
>>>>
>>>> The operations can be started from the Volumes tab or the Bricks sub-tab
>>>> using the Rebalance, Remove options.
>>>> These are long running operations which can be monitored using a task id
>>>> returned from Gluster. We are planning to add the monitoring in the
>>>> existing Task sub tab
>>>>
>>>> The feature description and User flows are at
>>>> http://www.ovirt.org/Features/Gluster_Volume_Asynchronous_Tasks_Management
>>>>
>>>> The detailed design (including REST API design) is at
>>>> http://www.ovirt.org/Features/Detailed_Gluster_Volume_Asynchronous_Tasks_Management.
>>>>
>>>> I would really appreciate if you could review and provide your valuable
>>>> feedback.
>>> I Sahina
>>> Why not using 6the External Tasks feature introduced for 3.3 for those
>>> Gluster tasks ???
>>> http://www.ovirt.org/Features/Design/DetailedExternalTasks
>> Hi Eli,
>>
>> We still want to be able to start and stop these operations from the engine.
>> So, when a user wants to say, rebalance a volume, they would go select
>> the volume and click on Rebalance Start.
>> This would then call the BLL command to start rebalance which will
>> invoke the corresponding vdsm verb to start the rebalance on the volume.
>> This is the same as existing flow for other commands. The only
>> difference is the vdsm verb will return the task id from gluster, for
>> the rebalance operation that was started. And we will monitor the
>> progress of the task using the gluster task id (by calling a gluster
>> command)
>>
>> I'm not sure how ExternalTasks would fit in here? I was thinking of
>> using ExternalTask support for adding Job/Steps to engine when the
>> operation is started outside of engine, that is, from Gluster CLI.
>> Please correct me if I'm missing something.
> Does this mean that from Gluster CLI you will not try and invoke the rebalance command ?
> (I mean, I should either use Gluster CLI or Engine's REST API?)
Rebalance volume command could be invoked in any of the following ways:
1. From the console UI (clicking on Rebalance as shown in 
http://www.ovirt.org/Features/Gluster_Volume_Asynchronous_Tasks_Management#Rebalance_Volume)
2. Using REST API
3. Outside of engine, from Gluster CLI - In such cases, the engine 
should detect that a user has triggered rebalance operation outside the 
engine, and allow the user to monitor progress of this from the engine. 
This is where, we need support to add a Job for an operation that was 
started externally, so that it can be seen in the Tasks tab.
>
>>
>>>
>>>
>>>> thanks
>>>> sahina
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