Eric MacDonald 0b079b4804 Add --timeout option to collect tool
This update adds a new --timeout command line option to the collect
tool so that users can extend collect's global timeout.

Prior to this update the collect tool had a fixed 1000 second
or 16.6 minute timeout. Collect of hosts in large busy systems can
take an unpredictably long time. Sometimes longer than 1000 seconds.
This can be particularly true when collecting from the active
controller deploying and managing lots of pods across many hosts.

This new timeout option allows the user to specify a specific timeout
in minutes, between 10 and 120, while defaulting to 20 minutes.
The default or user specified global timeout is passed to subclouds
for subcloud collect as well.

Test Plan:

PASS: Verify new --timeout or -t options at command line arg level
PASS: Verify --timeout <minutes> parse; error, in and out of bounds
PASS: Verify timeout option is described in collect help
PASS: Verify 110 minute collect with --timeout 120
PASS: Verify 45 minute collect times out with --timeout 40
PASS: Verify 2 minute collect with --timeout 10
PASS: Verify default timeout is 20 minutes
PASS: Verify default or specified timeout is displayed
PASS: Verify default or specified timeout is shared with the subcloud
PASS: Verify timeout error handling.
PASS: Verify collect error handling behavior if --timeout or -t is
      specified but the number of minutes is missing.

Regression:

PASS: Verify collect system and subcloud handling
PASS: Verify system and subcloud dated collects ; verified content
PASS: Verify collect with a variety of options

Closes-Bug: 2004666
Signed-off-by: Eric MacDonald <eric.macdonald@windriver.com>
Change-Id: Ib68b78f7c810f43fc8d13cbf291ac00f08c3c4f4
2023-02-14 13:14:14 -05:00
2019-10-24 13:23:53 -04:00
2019-09-09 13:43:49 -05:00
2019-09-09 13:43:49 -05:00
2022-12-27 01:31:42 +00:00

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 by int will be assigned to handle the interruptions from the PCI devices
  • int1-int2: the vCPUs between int1 and int2 (inclusive) will be used to handle the interruptions from the PCI devices
  • ^int: the vCPU expressed by int will 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.

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