[sheepdog] [PATCH v3] sheep/recovery: multi-threading recovery process

[Hitoshi Mitake]

At Tue, 4 Feb 2014 15:16:18 +0800,
Liu Yuan wrote:
> 
> On Tue, Feb 04, 2014 at 03:14:44PM +0800, Liu Yuan wrote:
> > Rationale for multi-threaded recovery:
> > 
> > 1. If one node is added, we find that all the VMs on other nodes will get
> >    noticeably affected until 50% data is transferred to the new node.
> > 
> > 2. For node failure, we might not have problems of running VM but the
> >    recovery process boost will benefit IO operation of VM with less
> >    chances to be blocked for write and also improve reliability.
> > 
> > 3. For disk failure in node, this is similar to adding a node. All
> >    the data on the broken disk will be recovered on other disks in
> >    this node. Speedy recoery not only improve data reliability but
> >    also cause less writing blocking on the lost data.
> > 
> > Our oid scheduling algorithm is intact and simply add multi-threading onto top
> > of current recovery algorithm with minimal changes.
> > 
> > - we still have ->oids array to denote oids to be recovered
> > - we start up 2 * nr_disks threads for recovery
> > - the tricky part is that we need to wait all the running threads to
> >   completion before start next recovery events for multiple nodes/disks events
> > 
> > This patch passes "./check -g md -md" on my local box
> > 
> 
> Hitoshi, can this one pass your test 033?

It passed 033 on my environment.

BTW, you should write differences between versions.

Thanks,
Hitoshi