Current Series Release Notes¶
Guru Meditation Reports can now be generated for the Nova API service when running under uWSGI. Note that uWSGI intercepts SIGUSR2 signals, so a file trigger should be used instead.
In this release the default values for the initial ram and cpu allocation ratios have been updated to 1.0 and 4.0 respectively. This will not affect any existing compute node resource providers but the new default will take effect on the creation of new resource providers.
For networks which have any subnets with enabled DHCP, MTU value is not send in the metadata. In such case MTU is configured through the DHCP server.
A workaround has been added to the libvirt driver to catch and pass migrations that were previously failing with the error:
libvirt.libvirtError: internal error: migration was active, but no RAM info was set
See bug 1982284 for more details.
The default initial allocation ratios enabled ram over commit by default with a factor of
1.5. This value was chosen early in nova’s history as the predominant workload was web hosting or other light weight virtualization. Similarly the default initial cpu allocation ratio defaulted to 16. As more demanding workload from telco, enterprise, scientific and governmental users became the norm the initial values we had chosen became less and less correct overtime. These have now been updated to reflect a more reasonable default for the majority of our users. As of this release the initial ram allocation value is 1.0 disabling overcommit by default for new compute nodes and the initial cpu allocation ratio is now 4.0 which is a more reasonable overcommit for non idle workloads.