56d3cd7aa7
In some situations, we may enter into a race-safe wait context for an external event and then determine within the context that the event would have already fired or for some other reason waiting is not required. In that case, this introduces a VirtAPI method to abort the wait for specific events in a clean way. This should be used sparingly and only in certain circumstances where it is clear that the event has already occurred. For example, if the action triggering the event was initiated outside of the wait context, we can enter the wait context (establishing a waiting event to capture), and then poll once for completion of that thing. If incomplete, we will block and wait on context exit as usual. If the thing we are waiting for has already completed, then we can avoid the long wait by calling the early-exit helper and avoid what would ultimately be a timeout and failure. We are specifically adding this to address the cyborg scenario as follows: Once we select a host in the conductor for an instance build, we can call to cyborg to start the preparation (i.e. programming) of the device on the destination host. This takes time, and by kicking it off early, we can overlap that process with other work we have to do. Because that will send an event upon completion, which will be routed to the compute, we will race to start the build process on the compute and begin the race-safe event wait in the compute manager. Instead of collapsing the window and waiting synchronously, we can trigger it early, then start the wait in the compute later, check for early completion *after* the wait has been set up, and then exit the wait early if we determine that the event had already been sent. This allows us to be async with cyborg across two services while still being safe in the critical region where we need to setup the wait before we rely on the event being sent. Change-Id: I8e5a0683069b2f322cb059d6eb501d732d1bd851 |
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|---|---|---|
| api-guide/source | ||
| api-ref/source | ||
| devstack | ||
| doc | ||
| etc/nova | ||
| gate | ||
| nova | ||
| playbooks | ||
| releasenotes | ||
| roles/run-post-test-hook | ||
| tools | ||
| .coveragerc | ||
| .gitignore | ||
| .gitreview | ||
| .mailmap | ||
| .stestr.conf | ||
| .zuul.yaml | ||
| CONTRIBUTING.rst | ||
| HACKING.rst | ||
| LICENSE | ||
| MAINTAINERS | ||
| README.rst | ||
| babel.cfg | ||
| bindep.txt | ||
| lower-constraints.txt | ||
| requirements.txt | ||
| setup.cfg | ||
| setup.py | ||
| test-requirements.txt | ||
| tox.ini | ||
README.rst
OpenStack Nova
OpenStack Nova provides a cloud computing fabric controller, supporting a wide variety of compute technologies, including: libvirt (KVM, Xen, LXC and more), Hyper-V, VMware, XenServer, OpenStack Ironic and PowerVM.
Use the following resources to learn more.
API
To learn how to use Nova's API, consult the documentation available online at:
For more information on OpenStack APIs, SDKs and CLIs in general, refer to:
Operators
To learn how to deploy and configure OpenStack Nova, consult the documentation available online at:
In the unfortunate event that bugs are discovered, they should be reported to the appropriate bug tracker. If you obtained the software from a 3rd party operating system vendor, it is often wise to use their own bug tracker for reporting problems. In all other cases use the master OpenStack bug tracker, available at:
Developers
For information on how to contribute to Nova, please see the contents of the CONTRIBUTING.rst.
Any new code must follow the development guidelines detailed in the HACKING.rst file, and pass all unit tests.
Further developer focused documentation is available at:
Other Information
During each Summit and Project Team Gathering, we agree on what the whole community wants to focus on for the upcoming release. The plans for nova can be found at: