Kubernetes: specify CPUs for cpumanager

Question

是否可以为Kubernetes cpumanager指定CPU ID列表？目标是确保pod从单个套接字(0(获取CPU。如上所述，我使对等套接字上的所有CPU离线，例如：

$ echo 0 > /sys/devices/system/cpu/cpu5/online

这样做之后，Kubernetes大师确实看到了剩余的在线CPU

kubectl describe node foo
Capacity:
cpu:                56   <<< socket 0 CPU count
ephemeral-storage:  958774760Ki
hugepages-1Gi:      120Gi
memory:             197524872Ki
pods:               110
Allocatable:
cpu:                54    <<< 2 system reserved CPUs
ephemeral-storage:  958774760Ki
hugepages-1Gi:      120Gi
memory:             71490952Ki
pods:               110
System Info:
Machine ID:                 1155420082478559980231ba5bc0f6f2
System UUID:                4C4C4544-0044-4210-8031-C8C04F584B32
Boot ID:                    7fa18227-748f-496c-968c-9fc82e21ecd5
Kernel Version:             4.4.13
OS Image:                   Ubuntu 16.04.4 LTS
Operating System:           linux
Architecture:               amd64
Container Runtime Version:  docker://17.3.3
Kubelet Version:            v1.11.1
Kube-Proxy Version:         v1.11.1

然而，cpumanager似乎仍然认为有112个CPU(socket0+socket1(。

cat /var/lib/kubelet/cpu_manager_state
{"policyName":"static","defaultCpuSet":"0-111"}

因此，kubelet系统pod抛出以下错误：

kube-system     kube-proxy-nk7gc                       0/1       rpc error: code = Unknown desc = failed to update container "eb455f81a61b877eccda0d35eea7834e30f59615346140180f08077f64896760": Error response from daemon: Requested CPUs are not available - requested 0-111, available: 0,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100,102,104,106,108,110   762        36d       <IP address>   foo      <none>

Answer 1

我能够让它工作起来。将此作为答案发布，以便有需要的人可以从中受益。

CPU集似乎是从/var/lib/kubelet/cpu_manager_state文件中读取的，并且在kubelet重新启动时不会更新。因此，在重新启动kubelet之前，需要删除此文件。

以下对我有效：

# On a running worker node, bring desired CPUs offline. (run as root)
$ cpu_list=`lscpu | grep "NUMA node1 CPU(s)" | awk '{print $4}'`
$ chcpu -d $cpu_list
$ rm -f /var/lib/kubelet/cpu_manager_state
$ systemctl restart kubelet.service
# Check the CPU set seen by the CPU manager
$ cat /var/lib/kubelet/cpu_manager_state
# Try creating pods and check the syslog:
Dec  3 14:36:05 k8-2-w1 kubelet[8070]: I1203 14:36:05.122466    8070 state_mem.go:84]     [cpumanager] updated default cpuset: "0,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100,102,104,106,108,110"
Dec  3 14:36:05 k8-2-w1 kubelet[8070]: I1203 14:36:05.122643    8070 policy_static.go:198] [cpumanager] allocateCPUs: returning "2,4,6,8,58,60,62,64"
Dec  3 14:36:05 k8-2-w1 kubelet[8070]: I1203 14:36:05.122660    8070 state_mem.go:76] [cpumanager] updated desired cpuset (container id: 356939cdf32d0f719e83b0029a018a2ca2c349fc0bdc1004da5d842e357c503a, cpuset: "2,4,6,8,58,60,62,64")

我在这里报告了一个错误，因为我认为CPU集应该在kubelet重新启动后更新。