5aadff75c3
This adds a new config option which is read on the destination host during pre_live_migration and the value is returned back to the source host, which can be used to determine, from the source host, if it should wait for a "network-vif-plugged" event due to VIFs being plugged on the destination host. This helps us to avoid the guest transfer at all if vif plugging failed on the dest host, which we just wouldn't find out until post live migration and then we have to rollback. The option is disabled by default for backward compatibility and also because certain networking backends, like OpenDaylight, are known to not send network-vif-plugged events unless the port host binding information changes, which for live migration doesn't happen until after the guest is transferred to the destination host. We could arguably avoid the changes to the live migrate data versioned object and just assume the same networking backend is used within each cell, but this does allow the deployer to have the flexibility of live migrating between different network backends (eventually anyway). The ability to live migrate between different VIF types is being worked on as part of blueprint neutron-new-port-binding-api. Related to blueprint neutron-new-port-binding-api Change-Id: I0f3ab6604d8b79bdb75cf67571e359cfecc039d8
21 lines
1.1 KiB
YAML
21 lines
1.1 KiB
YAML
---
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other:
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A new configuration option, ``[compute]/live_migration_wait_for_vif_plug``,
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has been added which can be used to configure compute services to wait
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for network interface plugging to complete on the destination host before
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starting the guest transfer on the source host during live migration.
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Note that this option is read on the destination host of a live migration.
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If you set this option the same on all of your compute hosts, which you
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should do if you use the same networking backend universally, you do not
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have to worry about this.
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This is disabled by default for backward compatibilty and because the
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compute service cannot reliably determine which types of virtual
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interfaces (``port.binding:vif_type``) will send ``network-vif-plugged``
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events without an accompanying port ``binding:host_id`` change.
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Open vSwitch and linuxbridge should be OK, but OpenDaylight is at least
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one known backend that will not currently work in this case, see bug
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https://launchpad.net/bugs/1755890 for more details.
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