[Gluster-devel] Consistent time attributes (ctime, atime and mtime) across replica set and distribution set

[Shyam]

On 03/08/2017 01:05 AM, Amar Tumballi wrote:
> son, for ex: because of locks.
>>>
>>>
>>> 2) On the server posix layer stores the value in the memory (inode ctx)
>>> and will sync the data periodically to the disk as an extended attr
>>
>> I believe this should not be a part of the posix xlator. our posix store
>> definition is that it uses a local file-system underneath that is POSIX
>> compliant. This need, for storing the time information outside of POSIX
>> specification (as an xattr or otherwise), is something that is gluster
>> specific. As a result we should not fold this into the posix xlator.
>>
>> For example, if we replace posix later with a db store, or a key-vlaue
>> store, we would need to code this cache management of time information
>> again for these stores, but if we abstract it out, then we do not need
>> to do the same.
>>
>
> I see this xattr similar to that of 'gfid'. Because as gfid is like our
> 'stat->st_ino', this xattr will be our 'stat->st_{c,m,a}time', which is
> very much a part of backend support requirement IMO.

Yes, that part I agree.

I am more talking about delayed sync of these attrs as a (possibly) 
separate layer, so that it can be utilized across other backends, if and 
when that happens.

>
>
>> I may need to chew on this further, but at the moment I think this
>> functionality should be stuffed into posix-xlator, and rather should
>> live on its own.
>>