[Gluster-devel] Client side afr, locking, race condition, simultanous writes, out of sync

[Gordan Bobic]

Martin Fick wrote:
> --- gordan at bobich.net wrote:
>> On Fri, 9 May 2008, Anand Babu Periasamy wrote:
>>> You are always expected to hold locks and issue
>>> writes in a multi user mode.
> 
> In the real world people will use scripts without 
> locks and will risk corruption.  This corruption 
> should only affect the application.  Here we are
> talking about backup utilities and other 
> applications that will potentially be affected. 
> Imagine a file that is inconsistent and untouched 
> for years after that, it could return alternating
> results every night on a backup making backups
> excessive.  It could trigger an rsynced volume to
> constantly resync.  These are not issues that a
> filesytem should introduce.
> 
> 
>> ... but what happens when both sides are 
>> appending to the file? Logs being an obvious 
>> example - they are not always locked.
> 
> For the record, I tested this yesterday and 
> if you modify the stress script to append to 
> each file; you will see similar inconsistent 
> split brain activity.

I couldn't agree more. These are all rather dangerous problems.

Could the developers please provide any insight into when these basic 
consistency issues are likely to be addressed and if the rest of us can 
help somehow?

Gordan