[sheepdog] question about replica recovery failure caused by oid.tmp file

[Hitoshi Mitake]

At Thu, 18 Sep 2014 17:28:27 +0800,
Ruoyu wrote:
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> On 2014?09?18? 16:30, Bingpeng Zhu wrote:
> > Thank you for the advice.
> > default_init() of sheep/store.chas already had the logic of unlinking 
> > oid.tmp files. I'm not sure the reason why oid.tmp file still exists 
> > in the system.
> No. current logic does not unlink oid.tmp files in default_init().

I agree with Ruoyu. Which part removes .tmp files?

Thanks,
Hitoshi

> >
> >
> >
> > ------------------ Original ------------------
> > *From: * "Hitoshi Mitake";<mitake.hitoshi at lab.ntt.co.jp>;
> > *Date: * Sep 18, 2014
> > *To: * "Ruoyu"<liangry at ucweb.com>;
> > *Cc: * "Bingpeng Zhu"<nkuzbp at foxmail.com>; 
> > "sheepdog"<sheepdog at lists.wpkg.org>;
> > *Subject: * Re: [sheepdog] question about replica recovery failure 
> > caused by oid.tmp file
> >
> > At Tue, 16 Sep 2014 10:10:32 +0800,
> > Ruoyu wrote:
> > >
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> > > Thanks Bingpeng.
> > > I also encountered this problem.
> > > I suggest sheep should scan oid.tmp files and remove them when it is
> > > being started.
> >
> > I agree with Ruoyu's opinion. .tmp files should be deleted at
> > initialization time. e.g. default_init() of sheep/store.c would be a
> > good place for it.
> >
> > Thanks,
> > Hitoshi
> >
> > >
> > > On 2014?09?15? 00:14, Bingpeng Zhu wrote:
> > > > Hi, all:
> > > >      I have a problem in using sheepdog. I create a erasure coded VDI
> > > > and write
> > > >   some data to it. Then, I unplug disk and stop/restart one sheep 
> > in a
> > > > short
> > > >   time. After recovery is completed in the latest epoch, I find some
> > > > replica is
> > > >   lost and only the corresponding oid.tmp file exists in the data
> > > > directory. I tried
> > > >   to rebuild the replica using "dog vdi check", but it didn't work. I
> > > > think it is
> > > >   caused by oid.tmp file. I have to delete the oid.tmp file manually
> > > > and then
> > > >   "dog vdi check" successfully recoverd the lost replica.
> > > >       In function default_create_and_write() of sheep/plain_store.c,
> > > > it returns
> > > >   success directly if oid.tmp file exists. I have read the comment in
> > > > this function carefully,
> > > >   it says gateway and recovery thread may try to write the SAME data,
> > > > so it is okay
> > > >   to simply return success here. To solve this problem, I want to
> > > > change the code of
> > > > default_create_and_write() so that replica data will be written even
> > > > oid.tmp file exists.
> > > >   If oid.tmp exists, the function should overwrite it.
> > > > I am not sure if this change will work good for all scenario.
> > > > Especially, I doubt whether
> > > >   this change will lead to old data overwriting new data. But I
> > > > haven't thought out any scenario
> > > >   that will lead to old data overwriting new data. Can someone 
> > give me
> > > > some advice to solve this problem?
> > > >
> > > >
> > > >
> > >
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