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node-feature-discovery/pkg/nfd-master/node-updater-pool.go
Markus Lehtonen 8ad6210d5c nfd-master: use separate k8s api clients for each updater
Sharing the same client between updater threads virtually serializes
access, in practice making the effective parallelism close to 1.

With this patch, in my bench cluster of 300 nodes, the time taken by
updating all nodes drops from ~2 minutes to ~12 seconds (with the
default parallelism of 10 node updater threads). This demonstrates the
10-fold increased parallelism from ~1 to 10.

There might be other solutions that could be explored, e.g. caching
nodes with an indexer/lister but otoh nfd doesn't necessarily need/want
to watch every little change in each node. We only need to get the node
when something in our own CRDs change (we don't react to any changes in
the node object itself). Using multiple clients was the most obvious
choice to solve the problem for now.
2024-04-15 19:00:30 +03:00

131 lines
3.5 KiB
Go

/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package nfdmaster
import (
"sync"
"time"
"golang.org/x/time/rate"
apierrors "k8s.io/apimachinery/pkg/api/errors"
k8sclient "k8s.io/client-go/kubernetes"
"k8s.io/client-go/util/workqueue"
"k8s.io/klog/v2"
)
type nodeUpdaterPool struct {
queue workqueue.RateLimitingInterface
sync.RWMutex
wg sync.WaitGroup
nfdMaster *nfdMaster
}
func newNodeUpdaterPool(nfdMaster *nfdMaster) *nodeUpdaterPool {
return &nodeUpdaterPool{
nfdMaster: nfdMaster,
wg: sync.WaitGroup{},
}
}
func (u *nodeUpdaterPool) processNodeUpdateRequest(cli k8sclient.Interface, queue workqueue.RateLimitingInterface) bool {
n, quit := queue.Get()
if quit {
return false
}
nodeName := n.(string)
defer queue.Done(nodeName)
nodeUpdateRequests.Inc()
// Check if node exists
if node, err := getNode(cli, nodeName); apierrors.IsNotFound(err) {
klog.InfoS("node not found, skip update", "nodeName", nodeName)
} else if err := u.nfdMaster.nfdAPIUpdateOneNode(cli, node); err != nil {
if n := queue.NumRequeues(nodeName); n < 15 {
klog.InfoS("retrying node update", "nodeName", nodeName, "lastError", err, "numRetries", n)
} else {
klog.ErrorS(err, "node update failed, queuing for retry ", "nodeName", nodeName, "numRetries", n)
// Count only long-failing attempts
nodeUpdateFailures.Inc()
}
queue.AddRateLimited(nodeName)
return true
}
queue.Forget(nodeName)
return true
}
func (u *nodeUpdaterPool) runNodeUpdater(queue workqueue.RateLimitingInterface) {
var cli k8sclient.Interface
if u.nfdMaster.kubeconfig != nil {
// For normal execution, initialize a separate api client for each updater
cli = k8sclient.NewForConfigOrDie(u.nfdMaster.kubeconfig)
} else {
// For tests, re-use the api client from nfd-master
cli = u.nfdMaster.k8sClient
}
for u.processNodeUpdateRequest(cli, queue) {
}
u.wg.Done()
}
func (u *nodeUpdaterPool) start(parallelism int) {
u.Lock()
defer u.Unlock()
if u.queue != nil && !u.queue.ShuttingDown() {
klog.InfoS("the NFD master node updater pool is already running.")
return
}
klog.InfoS("starting the NFD master node updater pool", "parallelism", parallelism)
// Create ratelimiter. Mimic workqueue.DefaultControllerRateLimiter() but
// with modified per-item (node) rate limiting parameters.
rl := workqueue.NewMaxOfRateLimiter(
workqueue.NewItemExponentialFailureRateLimiter(50*time.Millisecond, 100*time.Second),
&workqueue.BucketRateLimiter{Limiter: rate.NewLimiter(rate.Limit(10), 100)},
)
u.queue = workqueue.NewRateLimitingQueue(rl)
for i := 0; i < parallelism; i++ {
u.wg.Add(1)
go u.runNodeUpdater(u.queue)
}
}
func (u *nodeUpdaterPool) stop() {
u.Lock()
defer u.Unlock()
if u.queue == nil || u.queue.ShuttingDown() {
klog.InfoS("the NFD master node updater pool is not running.")
return
}
klog.InfoS("stopping the NFD master node updater pool")
u.queue.ShutDown()
u.wg.Wait()
}
func (u *nodeUpdaterPool) addNode(nodeName string) {
u.RLock()
defer u.RUnlock()
u.queue.Add(nodeName)
}