b6343a9e55
The current system_info plugin logs the system info for the last
host in host_dirs rather than that of the active controller.
It also does not capture the system info for all the nodes
into its plugin output file.
This update improves the system_info plugin as well implements
the following improvements to rendering and substring handling
improvements.
1. Improve system_info plugin capture and render.
2. Adds which controller was active at the time of the collect
to the system info rendering output.
3. Improve report analysis rendering by displaying the full
path to plugin and correlation files.
4. Adds string exclude support to the substring algorithm.
This allows the generic string rearches like ERROR to be
searched for and gathered while also allowing specific
noise logs what are considered noise logs to be filtered out.
5. Create a separate SM errors substring plugin using the new
exclude option.
6. Adds support for commented and empty lines in the plugins
This allows for properly commented and formatted plugins.
7. Adds plugin label name error checking
This allows esier debug of improperly coded plugins.
8. Fixed additional pep8 warnings.
Test Plan:
PASS: Verify on-system collect with --report option
PASS: Verify on-system report generation
PASS: Verify off-system report generation from git
PASS: Verify system_info plugin collects info from all hosts
PASS: Verify report displays system_info from active controller
PASS: Verify handling when no active controller is detected
PASS: Verify new sm_errors substring plugin with excludes
PASS: Verify plugins can have empty or # commented lines
PASS: Verify report tool plugins output include path to each
plugin file
PASS: Verify report tool correlations include path to each
correlation file
PASS: Verify report tool plugin label parsing error handling
PASS: Verify all files pass pep8 without warning or error
Story: 2010533
Task: 48072
Change-Id: I6d0253a4c3d8804a5e45b970d766e578ea69368f
Signed-off-by: Eric MacDonald <eric.macdonald@windriver.com>
utilities
This file serves as documentation for the components and features included on the utilities repository.
PCI IRQ Affinity Agent
While in OpenStack it is possible to enable instances to use PCI devices, the interrupts generated by these devices may be handled by host CPUs that are unrelated to the instance, and this can lead to a performance that is lower than it could be if the device interrupts were handled by the instance CPUs.
The agent only acts over instances with dedicated vCPUs. For instances using shared vCPUs no action will be taken by the agent.
The expected outcome from the agent operation is achieving a higher performance by assigning the instances core to handle the interrupts from PCI devices used by these instances and avoid interrupts consuming excessive cycles from the platform cores.
Agent operation
The agent operates by listening to RabbitMQ notifications from Nova. When an instance is created or moved to the host, the agent checks for an specific flavor spec (detailed below) and if it does then it queries libvirt to map the instance vCPUs into pCPUs from the host.
Once the agent has the CPU mapping, it determines the IRQ for each PCI device used by the instance, and then it loops over all PCI devices and determines which host NUMA node is associated with the device, the pCPUs that are associated with the NUMA node and finally set the CPU affinity for the IRQs of the PCI device based on the pCPU list.
There is also a periodic audit that runs every minute and loops over the existing IRQs, so that if there are new IRQs that weren't mapped before the agent maps them, and if there are PCI devices that aren't associated to an instance that they were before, their IRQ affinity is reset to the default value.
Flavor spec
The PCI IRQ Affinity Agent uses a specific flavor spec for PCI interrupt affining, that is used to determine which vCPUs assigned to the instance must handle the interrupts from the PCI devices:
hw:pci_irq_affinity_mask=<vcpus_cpulist>
Where vcpus_cpulist can assume a comma-separated list of
values that can be expressed as:
int: the vCPU expressed byintwill be assigned to handle the interruptions from the PCI devicesint1-int2: the vCPUs betweenint1andint2(inclusive) will be used to handle the interruptions from the PCI devices^int: the vCPU expressed byintwill not be assigned to handle the interruptions from the PCI devices and shall be used to exclude a vCPU that was included in a previous range
NOTE: int must be a value between
0 and flavor.vcpus - 1
Example: hw_pci_irq_affinity_mask=1-4,^3,6 means that
vCPUs with indexes 1,2,4 and 6 from the vCPU list that Nova
allocates to the instance will be assigned to handle interruptions from
the PCI devices.
Limitations
- No CPU affining is performed for instances using shared CPUs (i.e.,
when using flavor spec
hw:cpu_policy=shared) - No CPU affining will be performed when invalid ranges are specified on the flavor spec, the agent instead will log error messages indicating the problem
Agent packaging
The agent code resides on the starlingx/utilities repo,
along with the spec and docker_image files that are used to build a
CentOS image with the agent wheel installed on it.
The agent is deployed by Armada along with the other OpenStack helm
charts; refer to PCI
IRQ Affinity Agent helm chart on
starlingx/openstack-armada-app repository.