[Kimchi-devel] [PATCH] [Kimchi] Update Kimchi objectstore versioning.

[Rodrigo Trujillo]

On 12/14/2015 03:20 PM, Paulo Ricardo Paz Vital wrote:
> On 12/14/2015 01:06 PM, Rodrigo Trujillo wrote:
>> This solution works for Kimchi and Ginger now, but I analyzed it a bit
>> deeper and I cannot see it as a good long-term solution.
> I think the first and most important point you should see here is that
> Wok provides the objectstore structure for any plugin wants to use it.
> So, since a plugin is using the Wok's objectstore structure, the
> solution will works.
>
> Second, this change came from a Ginger and GingerBase issue regarding
> the missing 'version' field on their structure, something solved in
> Kimchi by commit 50b104a46e65047dfdf299ff8a5f652f2422a949.
>
> In addition, this patch depends on Wok's patch I sent a little bit early.
>
>> Reasons:
>> - other plugins will never be allowed to have a column named version in
>> its table, for whatever reason they want;
> It's false. Once a plugin is using Wok's ObjectStore structure, a column
> version will be present starting on version 2.0.0. See commit
> fec97768abc8b407d4eaaca2fc892708da7210c9
I see. I thought that version was tied to Wok's version...
>
>> - every new record must have the version inserted, today we cannot
>> measure the impact, but, if for some reason objectstore must be heavily
>> used, this can impact;
> The complexity to record the version is the same of any other
> information, since it's done once - when all information is recorded.
I was talking about disk space and time to save/retrieve information.

>
>> - we will have (or each plugin will have) to change this in future,
>> because all 'object' tables will have 'version' column, then each plugin
>> will have to manage by itself how to check and update the records or
>> schemas;
> Kimchi already fixed this. Patches to Ginger and GingerBase was already
> submitted to Ginger ML.
Thats why I said that works only for Kimchi/Ginger[Base] ...
WOK should be independent of plugin, what I see, is that wok is being 
used to fix problems that the plugins should fix.

Actually, plugins will have to check the version of records in the future.

>
>> - finally, I think that Wok should not touch plugins 'objectstore'.
>>
> Why not? It's a common infra-structure provided and that any plugin can
> use. All current plugins (kimchi, ginger and gingerbase) that use
> objectstore have a solution to this problem.

Bacause Wok is modifying what should be a private database.
Its ok Wok provides the infra (creates the db, provide functions to 
add/remove/update, etc), it should not
touch the data.

>> Like I said, this solution works for Kimchi/Ginger now, and I am ok,
>> once we are running out of time.
>> But keep in mind , that we are going to have rework in future.
>> Aline can decide what to do.
>>
>> Reviewed-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
>>
>>
>> On 12/14/2015 11:46 AM, pvital at linux.vnet.ibm.com wrote:
>>> From: Paulo Vital <pvital at linux.vnet.ibm.com>
>>>
>>> This patch is part of the solution for the Ginger Issue #51 and it
>>> depends on
>>> Wok's "Upgrade objectstore schema" patch.
>>>
>>> With the new structure of the objectstore changed in Wok 2.0.0, the
>>> schema of
>>> the objectstore file needs to be checked and, if necessary, updated to
>>> reflect
>>> the new structure.
>>>
>>> This patch removes from Kimchi the methods used to check the
>>> objectstore schema
>>> and upgrade it if necessary. These methods are now present in
>>> wok.plugins and
>>> are common to any Wok plugin.
>>>
>>> Paulo Vital (1):
>>>     Update Kimchi objectstore versioning.
>>>
>>>    root.py  |  4 ++--
>>>    utils.py | 40 ----------------------------------------
>>>    2 files changed, 2 insertions(+), 42 deletions(-)
>>>
>>> -- 
>>> 2.5.0
>>>
>>> _______________________________________________
>>> Kimchi-devel mailing list
>>> Kimchi-devel at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/kimchi-devel
>>>
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