[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH 0/7] COarse-grain LOck-stepping Virtual Machines for Non-stop Service
Virtual machine (VM) replication is a well known technique for providing application-agnostic software-implemented hardware fault tolerance - "non-stop service". Currently, remus provides this function, but it buffers all output packets, and the latency is unacceptable. In xen summit 2012, We introduce a new VM replication solution: colo (COarse-grain LOck-stepping virtual machine). The presentation is in the following URL: http://www.slideshare.net/xen_com_mgr/colo-coarsegrain-lockstepping-virtual-machines-for-nonstop-service Here is the summary of the solution: >From the client's point of view, as long as the client observes identical responses from the primary and secondary VMs, according to the service semantics, then the secondary VM(SVM) is a valid replica of the primary VM(PVM), and can successfully take over when a hardware failure of the PVM is detected. This patchset is RFC, and implements the frame of colo: 1. Both PVM and SVM are running 2. Forward the input packets from client to secondary machine(slaver) 3. Forward the output packets from SVM to primary machine(master) 4. Compare the output packets from PVM and SVM on the master side. If the output packets are different, do a checkpoint Changelog: Patch 1: optimize the dirty pages transfer speed. Patch 2-3: allow SVM running after checkpoint Patch 4-5: modification for colo on the master side(wait a new checkpoint, communicate with slaver when doing checkoint) Patch 6-7: implement colo's user interface Wen Congyang (7): xc_domain_save: cache pages mapping xc_domain_restore: introduce restore_callbacks for colo colo: implement restore_callbacks xc_domain_save: flush cache before calling callbacks->postcopy() xc_domain_save: implement save_callbacks for colo XendCheckpoint: implement colo remus: implement colo mode tools/libxc/Makefile | 4 +- tools/libxc/ia64/xc_ia64_linux_restore.c | 3 +- tools/libxc/xc_domain_restore.c | 256 +++++--- tools/libxc/xc_domain_restore_colo.c | 740 ++++++++++++++++++++++ tools/libxc/xc_domain_save.c | 162 +++-- tools/libxc/xc_save_restore_colo.h | 44 ++ tools/libxc/xenguest.h | 57 +- tools/libxl/libxl_dom.c | 2 +- tools/python/xen/lowlevel/checkpoint/checkpoint.c | 289 ++++++++- tools/python/xen/lowlevel/checkpoint/checkpoint.h | 2 + tools/python/xen/remus/image.py | 7 +- tools/python/xen/remus/save.py | 6 +- tools/python/xen/xend/XendCheckpoint.py | 138 ++-- tools/remus/remus | 8 +- tools/xcutils/xc_restore.c | 3 +- xen/include/public/xen.h | 1 + 16 files changed, 1503 insertions(+), 219 deletions(-) create mode 100644 tools/libxc/xc_domain_restore_colo.c create mode 100644 tools/libxc/xc_save_restore_colo.h -- 1.8.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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