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Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver
From: |
Liu Yuan |
Subject: |
Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver |
Date: |
Wed, 10 Sep 2014 15:18:22 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Sun, Sep 07, 2014 at 05:12:31PM +0200, Benoît Canet wrote:
> The Monday 01 Sep 2014 à 15:43:06 (+0800), Liu Yuan wrote :
> > This patch set mainly add mainly two logics to implement device recover
> > - notify qourum driver of the broken states from the child driver(s)
> > - dirty track and sync the device after it is repaired
> >
> > Thus quorum allow VMs to continue while some child devices are broken and
> > when
> > the child devices are repaired and return back, we sync dirty bits during
> > downtime to keep data consistency.
> >
> > The recovery logic is based on the driver state bitmap and will sync the
> > dirty
> > bits with a timeslice window in a coroutine in this prtimive implementation.
> >
> > Simple graph about 2 children with threshold=1 and read-pattern=fifo:
> > (similary to DRBD)
> >
> > + denote device sync iteration
> > - IO on a single device
> > = IO on two devices
> >
> > sync complete, release dirty bitmap
> > ^
> > |
> > ====-----------------++++----++++----++==========
> > | |
> > | v
> > | device repaired and begin to sync
> > v
> > device broken, create a dirty bitmap
> >
> > This sync logic can take care of nested broken problem, that devices are
> > broken while in sync. We just start a sync process after the devices are
> > repaired again and switch the devices from broken to sound only when the
> > sync
> > completes.
> >
> > For read-pattern=quorum mode, it enjoys the recovery logic without any
> > problem.
> >
> > Todo:
> > - use aio interface to sync data (multiple transfer in one go)
> > - dynamic slice window to control sync bandwidth more smoothly
> > - add auto-reconnection mechanism to other protocol (if not support yet)
> > - add tests
> >
> > Cc: Eric Blake <address@hidden>
> > Cc: Benoit Canet <address@hidden>
> > Cc: Kevin Wolf <address@hidden>
> > Cc: Stefan Hajnoczi <address@hidden>
> >
> > Liu Yuan (8):
> > block/quorum: initialize qcrs.aiocb for read
> > block: add driver operation callbacks
> > block/sheepdog: propagate disconnect/reconnect events to upper driver
> > block/quorum: add quorum_aio_release() helper
> > quorum: fix quorum_aio_cancel()
> > block/quorum: add broken state to BlockDriverState
> > block: add two helpers
> > quorum: add basic device recovery logic
> >
> > block.c | 17 +++
> > block/quorum.c | 324
> > +++++++++++++++++++++++++++++++++++++++++-----
> > block/sheepdog.c | 9 ++
> > include/block/block.h | 9 ++
> > include/block/block_int.h | 6 +
> > trace-events | 5 +
> > 6 files changed, 336 insertions(+), 34 deletions(-)
> >
> > --
> > 1.9.1
> >
>
> Hi liu,
>
> Had you noticed that your series conflict with one of Fam's series in the
> quorum cancel
> function fix patch ?
Not yet, thanks for reminding.
> Could you find an arrangement with Fam so the two patches don't collide
> anymore ?
>
> Do you intend to respin your series ?
Yes, I'll rebase the v2 later before more possible reviews.
Thanks
Yuan
- Re: [Qemu-devel] [PATCH 6/8] block/quorum: add broken state to BlockDriverState, (continued)
- [Qemu-devel] [PATCH 7/8] block: add two helpers, Liu Yuan, 2014/09/01
- [Qemu-devel] [PATCH 8/8] quorum: add basic device recovery logic, Liu Yuan, 2014/09/01
- Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver, Benoît Canet, 2014/09/01
- Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver, Benoît Canet, 2014/09/02
- Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver, Benoît Canet, 2014/09/07
- Re: [Qemu-devel] [PATCH 0/8] add basic recovery logic to quorum driver,
Liu Yuan <=