[Gluster-devel] Re: AFR load-balancing

[Székelyi Szabolcs]

Krishna Srinivas wrote:
> On Nov 16, 2007 11:48 PM, Székelyi Szabolcs <cc at avaxio.hu> wrote:
>> Krishna Srinivas wrote:
>>> "option read-node <sobvol>" will read from that particular subvol
>>> (this will help when that subvol is local storage)
>>> "option read-node *" will load balance from all children.
>>> So option is either * or one of the subvols.
>>> default is "option read-node *"
>>> What do you think about it?
>>
>> What about explicitly listing the subvolumes to perform load-balancing
>> between? For example, "option read-nodes child1 child3" could cause AFR
>> to load-balance reads between child1 and child3, while writing to all
>> its children (child[1-3], say). The default option could be to read from
>> the first child. "option read-nodes *" could still mean to use all
>> subvolumes.
> 
> We thought about "option read-node child1,child3" but this wont really
> be used in the sense that users would want to read either from local
> storage or all the children. But there might be a case where one of the
> sobvols might be a low end machine where we dont want to schedule
> reads. Still thinking if it is worth implementing this particular feature.

Consider the situation when I want to have 4-5 local (ie. on-site)
mirrors for (read) performance, and also a few remote (ie. off-site, on
the other end of a lower bandwidth link) for backup. This is not an
unusual setup.

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cc