[Gluster-devel] Server-side AFR + Failover and mixed server/client-side AFR
gordan at bobich.net
gordan at bobich.net
Wed May 7 08:37:50 UTC 2008
On Wed, 7 May 2008, Krishna Srinivas wrote:
>>>> > Is this an issue in server-side-only AFR? I have two servers which
>>>> > are also clients of themselves, and they both list their local
>>>> > subvolume first and
>>>> > remote subvolume second. Is this a problem? What are the possible
>>>> > consequences of this?
>>>>
>>>> It will be a problem. The "first" subvol is always the "lock" server.
>>>> Consider a case where you are creating a file simultaneously
>>>> on two clients, only one of them should succeed. If AFR's
>>>> subvols order are not same, chances are that both client
>>>> returns success for file creation with same name.
>>>>
>>>
>>> Hence you have "option read-subvlume" to speeden the
>>> read() calls so that it can be done from local subvol.
>>>
>>
>> So, what happens if the "lock" server is the one that goes down? Will that
>> render the whole AFR cluster inoperable, at least for writes?
>>
>
> If first server is down, the second one is tried and so on. The cluster remains
> operable.
Does the lock state remain for the locks when the primary/lock server
dies? If so, how?
Gordan
More information about the Gluster-devel
mailing list