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Re: [Qemu-devel] [RFC PATCH v2 00/23] COarse-grain LOck-stepping(COLO) V
From: |
Wen Congyang |
Subject: |
Re: [Qemu-devel] [RFC PATCH v2 00/23] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service |
Date: |
Wed, 29 Oct 2014 14:53:41 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 |
On 09/23/2014 05:23 PM, Yang Hongyang wrote:
> Virtual machine (VM) replication is a well known technique for
> providing application-agnostic software-implemented hardware fault
> tolerance "non-stop service". COLO is a high availability solution.
> Both primary VM (PVM) and secondary VM (SVM) run in parallel. They
> receive the same request from client, and generate response in parallel
> too. If the response packets from PVM and SVM are identical, they are
> released immediately. Otherwise, a VM checkpoint (on demand) is
> conducted. The idea is presented in Xen summit 2012, and 2013,
> and academia paper in SOCC 2013. It's also presented in KVM forum
> 2013:
> http://www.linux-kvm.org/wiki/images/1/1d/Kvm-forum-2013-COLO.pdf
> Please refer to above document for detailed information.
> Please also refer to previous posted RFC proposal:
> http://lists.nongnu.org/archive/html/qemu-devel/2014-06/msg05567.html
>
> The patchset is also hosted on github:
> https://github.com/macrosheep/qemu/tree/colo_v0.5
>
> v2:
> use QEMUSizedBuffer/QEMUFile as COLO buffer
> colo support is enabled by default
> add nic replication support
> addressed comments from Eric Blake and Dr. David Alan Gilbert
>
> v1:
> implement the frame of colo
>
> This patchset is RFC, But it is ready for demo the COLO idea
> with QEMU-KVM.
> Steps using this patchset to get an overview of COLO:
> 1. configure
> 2. compile
> 3. just like QEMU's normal migration, run 2 QEMU VM:
> - Primary VM
> - Secondary VM with -incoming tcp:[IP]:[PORT] option
> 4. on Primary VM's QEMU monitor, run following command:
> migrate_set_capability colo on
> migrate tcp:[IP]:[PORT]
> 5. done
> you will see two runing VMs, whenever you make changes to PVM, SVM
> will be synced to PVM's state.
>
> TODO list:
> 1. failover (will require heartbeat module:
> http://www.linux-ha.org/wiki/Downloads)
> 2. disk replication[COLO Disk manager]
Hi all:
I will start to implement disk replication. Before doing this, I think we
should decide
how to implement it.
I have two ideas about it:
1. implement it in qemu
Advantage: very easy, and don't take too much time
Disadvantage: the virtio disk with vhost is not supported, because the disk
I/O
operations are not handled in qemu.
2. update drbd and make it support colo
Advantage: we can use it for both KVM and XEN.
Disadvantage: The implementation may be complex, and need too much time to
implement it.(I don't read the drbd's codes, and can't estimate the
cost)
I think we can use 1 to implement it first.
If you have some other idea, please let me know.
Thanks
Wen Congyang
>
> Any comments/feedbacks are warmly welcomed.
>
> Thanks,
> Yang
>
>
> Dr. David Alan Gilbert (1):
> QEMUSizedBuffer/QEMUFile
>
> Yang Hongyang (22):
> configure: add CONFIG_COLO to switch COLO support
> COLO: introduce an api colo_supported() to indicate COLO support
> COLO migration: add a migration capability 'colo'
> COLO info: use colo info to tell migration target colo is enabled
> COLO save: integrate COLO checkpointed save into qemu migration
> COLO restore: integrate COLO checkpointed restore into qemu restore
> COLO: disable qdev hotplug
> COLO ctl: implement API's that communicate with colo agent
> COLO ctl: introduce is_slave() and is_master()
> COLO ctl: implement colo checkpoint protocol
> COLO ctl: add a RunState RUN_STATE_COLO
> COLO ctl: implement colo save
> COLO ctl: implement colo restore
> COLO save: reuse migration bitmap under colo checkpoint
> COLO ram cache: implement colo ram cache on slave
> HACK: trigger checkpoint every 500ms
> COLO nic: add command line switch
> COLO nic: init/remove colo nic devices when add/cleanup tap devices
> COLO nic: implement colo nic device interface support_colo()
> COLO nic: implement colo nic device interface configure()
> COLO nic: export colo nic APIs
> COLO nic: setup/teardown colo nic devices
>
> Makefile.objs | 2 +
> arch_init.c | 174 +++++++++++-
> configure | 14 +
> include/exec/cpu-all.h | 1 +
> include/migration/migration-colo.h | 36 +++
> include/migration/migration.h | 13 +
> include/migration/qemu-file.h | 28 ++
> include/net/colo-nic.h | 20 ++
> include/net/net.h | 4 +
> include/qemu/typedefs.h | 1 +
> migration-colo-comm.c | 78 ++++++
> migration-colo.c | 540
> +++++++++++++++++++++++++++++++++++++
> migration.c | 47 ++--
> net/Makefile.objs | 1 +
> net/colo-nic.c | 227 ++++++++++++++++
> net/tap.c | 45 +++-
> network-colo | 194 +++++++++++++
> qapi-schema.json | 18 +-
> qemu-file.c | 410 ++++++++++++++++++++++++++++
> qemu-options.hx | 10 +-
> stubs/Makefile.objs | 1 +
> stubs/migration-colo.c | 34 +++
> vl.c | 12 +
> 23 files changed, 1879 insertions(+), 31 deletions(-)
> create mode 100644 include/migration/migration-colo.h
> create mode 100644 include/net/colo-nic.h
> create mode 100644 migration-colo-comm.c
> create mode 100644 migration-colo.c
> create mode 100644 net/colo-nic.c
> create mode 100755 network-colo
> create mode 100644 stubs/migration-colo.c
>
- Re: [Qemu-devel] [RFC PATCH v2 00/23] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service,
Wen Congyang <=