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Merge pull request #6207 from brendandburns/server

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Add a limit to the number of in-flight requests that a server processes.
This commit is contained in:
Quinton Hoole
2015-04-02 15:46:54 -07:00
parent ee98731a2a f327e97661
commit 4a2000c4aa
3 changed files with 113 additions and 6 deletions
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16
cmd/kube-apiserver/app/server.go
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@@ -24,6 +24,7 @@ import (
"net"
"net/http"
"os"
"regexp"
"strconv"
"strings"
"time"
@@ -77,6 +78,8 @@ type APIServer struct {
KubeletConfig client.KubeletConfig
ClusterName string
EnableProfiling bool
MaxRequestsInFlight int
LongRunningRequestRE string
}
// NewAPIServer creates a new APIServer object with default parameters
@@ -157,6 +160,8 @@ func (s *APIServer) AddFlags(fs *pflag.FlagSet) {
fs.StringVar(&s.ClusterName, "cluster_name", s.ClusterName, "The instance prefix for the cluster")
fs.BoolVar(&s.EnableProfiling, "profiling", false, "Enable profiling via web interface host:port/debug/pprof/")
fs.StringVar(&s.ExternalHost, "external_hostname", "", "The hostname to use when generating externalized URLs for this master (e.g. Swagger API Docs.)")
fs.IntVar(&s.MaxRequestsInFlight, "max_requests_inflight", 20, "The maximum number of requests in flight at a given time. When the server exceeds this, it rejects requests. Zero for no limit.")
fs.StringVar(&s.LongRunningRequestRE, "long_running_request_regexp", "[.*\\/watch$][^\\/proxy.*]", "A regular expression matching long running requests which should be excluded from maximum inflight request handling.")
}
// TODO: Longer term we should read this from some config store, rather than a flag.
@@ -300,12 +305,19 @@ func (s *APIServer) Run(_ []string) error {
// See the flag commentary to understand our assumptions when opening the read-only and read-write ports.
var sem chan bool
if s.MaxRequestsInFlight > 0 {
sem = make(chan bool, s.MaxRequestsInFlight)
}
longRunningRE := regexp.MustCompile(s.LongRunningRequestRE)
if roLocation != "" {
// Default settings allow 1 read-only request per second, allow up to 20 in a burst before enforcing.
rl := util.NewTokenBucketRateLimiter(s.APIRate, s.APIBurst)
readOnlyServer := &http.Server{
Addr: roLocation,
Handler: apiserver.RecoverPanics(apiserver.ReadOnly(apiserver.RateLimit(rl, m.InsecureHandler))),
Handler: apiserver.MaxInFlightLimit(sem, longRunningRE, apiserver.RecoverPanics(apiserver.ReadOnly(apiserver.RateLimit(rl, m.InsecureHandler)))),
ReadTimeout: 5 * time.Minute,
WriteTimeout: 5 * time.Minute,
MaxHeaderBytes: 1 << 20,
@@ -325,7 +337,7 @@ func (s *APIServer) Run(_ []string) error {
if secureLocation != "" {
secureServer := &http.Server{
Addr: secureLocation,
Handler: apiserver.RecoverPanics(m.Handler),
Handler: apiserver.MaxInFlightLimit(sem, longRunningRE, apiserver.RecoverPanics(m.Handler)),
ReadTimeout: 5 * time.Minute,
WriteTimeout: 5 * time.Minute,
MaxHeaderBytes: 1 << 20,