func (bp *Backplane) handleStats(w http.ResponseWriter, req *http.Request) {
tr := trace.New("backend.internalstats", req.RequestURI)
defer tr.Finish()
hostname, err := os.Hostname()
if err != nil {
glog.Error("Unable to obtain hostname: ", err)
tr.LazyPrintf("Unable to obtain hostname: ", err)
}
var data = struct {
Backends []*Backend
Frontends []*Frontend
Pid int
Hostname string
Uptime time.Duration
LimitAs, LimitFsize, LimitNofile syscall.Rlimit
}{
Backends: bp.Backends,
Frontends: bp.Frontends,
Pid: os.Getpid(),
Hostname: hostname,
Uptime: time.Since(starttime),
}
syscall.Getrlimit(syscall.RLIMIT_AS, &data.LimitAs)
syscall.Getrlimit(syscall.RLIMIT_FSIZE, &data.LimitFsize)
syscall.Getrlimit(syscall.RLIMIT_NOFILE, &data.LimitNofile)
err = StatsTemplate().Execute(w, &data)
if err != nil {
glog.Errorf("unable to execute template: %s", err)
tr.LazyPrintf("unable to execute template: %s", err)
}
}
// MaximizeOpenFileLimit tries to set the resource limit RLIMIT_NOFILE (number
// of open file descriptors) to the max (hard limit), if the current (soft
// limit) is below the max. Returns the new (though possibly unchanged) limit,
// or an error if it could not be changed.
func MaximizeOpenFileLimit() (int, error) {
// Get the current limit on number of open files.
var lim syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim); err != nil {
return 0, err
}
// If we're already at max, there's no need to try to raise the limit.
if lim.Cur >= lim.Max {
return int(lim.Cur), nil
}
// Try to increase the limit to the max.
oldLimit := lim.Cur
lim.Cur = lim.Max
if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lim); err != nil {
return int(oldLimit), err
}
// If the set succeeded, perform a new get to see what happened. We might
// have gotten a value lower than the one in lim.Max, if lim.Max was
// something that indicated "unlimited" (i.e. intmax).
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim); err != nil {
// We don't really know the correct value here since Getrlimit
// mysteriously failed after working once... Shouldn't ever happen, I
// think.
return 0, err
}
return int(lim.Cur), nil
}
func main() {
var rlim syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
if err != nil {
fmt.Errorf("获取Rlimit报错 %s", err)
os.Exit(1)
}
fmt.Printf("ENV RLIMIT_NOFILE : %+v\n", rlim)
rlim.Max = 65535
rlim.Cur = 65535
//err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlim)
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlim)
if err != nil {
fmt.Errorf("设置Rlimit报错 %s", err)
os.Exit(1)
}
//fmt.Printf("ENV RLIMIT_NOFILE : %+v\n", rlim)
err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
if err != nil {
fmt.Errorf("获取Rlimit报错 %s", err)
os.Exit(1)
}
fmt.Printf("ENV RLIMIT_NOFILE : %+v\n", rlim)
}
func TestRlimit(t *testing.T) {
var rlimit, zero syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit)
if err != nil {
t.Fatalf("Getrlimit: save failed: %v", err)
}
if zero == rlimit {
t.Fatalf("Getrlimit: save failed: got zero value %#v", rlimit)
}
set := rlimit
set.Cur = set.Max - 1
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &set)
if err != nil {
t.Fatalf("Setrlimit: set failed: %#v %v", set, err)
}
var get syscall.Rlimit
err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &get)
if err != nil {
t.Fatalf("Getrlimit: get failed: %v", err)
}
set = rlimit
set.Cur = set.Max - 1
if set != get {
t.Fatalf("Rlimit: change failed: wanted %#v got %#v", set, get)
}
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlimit)
if err != nil {
t.Fatalf("Setrlimit: restore failed: %#v %v", rlimit, err)
}
}
func main() {
lim := &syscall.Rlimit{}
syscall.Getrlimit(syscall.RLIMIT_NOFILE, lim)
lim.Cur = 15
syscall.Setrlimit(syscall.RLIMIT_NOFILE, lim)
fmt.Println(lim)
var s []*os.File
for i := 0; i < int(lim.Max+10); i++ {
f, err := os.Open("/tmp/whj.txt")
fmt.Println(f, err)
s = append(s, f)
err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, lim)
fmt.Println(lim, err)
}
err := syscall.Getrlimit(syscall.RLIMIT_CORE, lim)
fmt.Println(lim, err)
rusage := &syscall.Rusage{}
err = syscall.Getrusage(0, rusage)
fmt.Println(rusage, err)
err = syscall.Getrusage(1, rusage)
fmt.Println(rusage, err)
err = syscall.Getrusage(2, rusage)
fmt.Println(rusage, err)
err = syscall.Getrusage(3, rusage)
fmt.Println(rusage, err)
err = syscall.Getrusage(4, rusage)
fmt.Println(rusage, err)
}
func fdlimit() int {
var nofile syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &nofile); err != nil {
return 0
}
return int(nofile.Cur)
}
func getFdLimit() uint64 {
var rlim syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim); err != nil {
panic(err)
}
return rlim.Max
}
func server_func(port *string) {
// check for max_allowed ?
var rlimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit)
if err != nil {
log.Fatal("syscall.Getrlimit | ", err)
}
// if server run the server
l := start_listener(*port)
defer l.Close()
log.Println("the listener started on port " + *port)
// now we need to accept the comming req
// but B4 that we need to check for openfd's
for {
// refresh the number of openfd's
nofile := check_open_fd()
// log.Printf("the new number of openfd's %d\n", nofile)
// check them ?
if rlimit.Cur > nofile {
// if no problem accept the new connection
c, err := l.Accept()
if err != nil {
log.Fatal("l.Accept ", err)
}
// defer c.Close()
go handleConn(c)
}
}
}
func maxOpenFiles() int {
var rlim syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim); err != nil {
return defaultMaxOpenFiles
}
return int(rlim.Cur)
}
func (fs *Fs) Attach() error {
fs.fidLock.Lock()
defer fs.fidLock.Unlock()
// Load the root.
var err error
fs.root, err = fs.lookup("/")
if err != nil {
return err
}
if fs.Fdlimit == 0 {
// Figure out our active limit (1/2 open limit).
// We use 1/2 because control connections, tap devices,
// disks, etc. all need file descriptors. Note that we
// also explicitly handle running out of file descriptors,
// but this gives us an open bound to leave room for the
// rest of the system (because pieces don't always handle
// an EMFILE or ENFILE appropriately).
var rlim syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
if err != nil {
return err
}
fs.Fdlimit = uint(rlim.Cur) / 2
}
return nil
}
func maxFD() (uint64, error) {
var rlim syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim); err != nil {
return 0, fmt.Errorf("ulimit error: %v", err)
}
return rlim.Cur, nil
}
func main() {
runtime.GOMAXPROCS(runtime.NumCPU())
os.Setenv("GOTRACEBACK", "crash")
lim := syscall.Rlimit{}
syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim)
if lim.Cur < _MaxOpenfile || lim.Max < _MaxOpenfile {
lim.Cur = _MaxOpenfile
lim.Max = _MaxOpenfile
syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lim)
}
ln, err := net.Listen("tcp", ":1153")
if err != nil {
log.Fatal(err)
}
go TCPServer(ln, queryTypeDNS)
ln, err = net.Listen("tcp", ":1154")
if err != nil {
log.Fatal(err)
}
go TCPServer(ln, queryTypeMYIP)
http.HandleFunc("/myip", HTTPServerMYIP)
http.HandleFunc("/dns", HTTPServerDNS)
http.HandleFunc("/health", HTTPServerHealth)
log.Fatal(http.ListenAndServe(":1053", nil))
}
func newHerd(imageServerAddress string, logger *log.Logger) *Herd {
var herd Herd
herd.imageServerAddress = imageServerAddress
herd.logger = logger
herd.subsByName = make(map[string]*Sub)
herd.imagesByName = make(map[string]*image.Image)
herd.missingImages = make(map[string]time.Time)
// Limit concurrent connection attempts so that the file descriptor limit is
// not exceeded.
var rlim syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim); err != nil {
panic(err)
}
maxConnAttempts := rlim.Cur - 50
maxConnAttempts = (maxConnAttempts / 100)
if maxConnAttempts < 1 {
maxConnAttempts = 1
} else {
maxConnAttempts *= 100
}
herd.connectionSemaphore = make(chan bool, maxConnAttempts)
herd.pollSemaphore = make(chan bool, runtime.NumCPU()*2)
herd.currentScanStartTime = time.Now()
return &herd
}
// Set Max File Descriptor limits
//
// Background information:
//
// - SG docs
// http://developer.couchbase.com/documentation/mobile/1.1.0/develop/guides/sync-gateway/os-level-tuning/max-file-descriptors/index.html
// - Related SG issues
// https://github.com/couchbase/sync_gateway/issues/1083
// - Hard limit vs Soft limit
// http://unix.stackexchange.com/questions/29577/ulimit-difference-between-hard-and-soft-limits
func SetMaxFileDescriptors(requestedSoftFDLimit uint64) (uint64, error) {
var limits syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limits); err != nil {
return 0, err
}
requiresUpdate, recommendedSoftFDLimit := getSoftFDLimit(
requestedSoftFDLimit,
limits,
)
// No call to Setrlimit required, because the requested soft limit is lower than current soft limit
if !requiresUpdate {
return 0, nil
}
// Update the soft limit (but don't bother updating the hard limit, since only root can do that,
// and it's assumed that this process is not running as root)
limits.Cur = recommendedSoftFDLimit
err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limits)
if err == nil {
Logf("Configured process to allow %d open file descriptors", recommendedSoftFDLimit)
}
return recommendedSoftFDLimit, err
}
func checkAndSetUlimit() error {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return fmt.Errorf("error getting rlimit: %s", err)
}
ipfsFileDescNum := int64(ipfsFileDescNum)
var setting bool
if rLimit.Cur < ipfsFileDescNum {
if rLimit.Max < ipfsFileDescNum {
log.Error("adjusting max")
rLimit.Max = ipfsFileDescNum
}
fmt.Printf("Adjusting current ulimit to %d...\n", ipfsFileDescNum)
rLimit.Cur = ipfsFileDescNum
setting = true
}
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return fmt.Errorf("error setting ulimit: %s", err)
}
if setting {
fmt.Printf("Successfully raised file descriptor limit to %d.\n", ipfsFileDescNum)
}
return nil
}
func testSlowClient(t *testing.T, name string, numMessages, numSlowClients, numNormalClients, slowDelay, timeout int) {
syscall.Getrlimit(syscall.RLIMIT_NOFILE, &syscall.Rlimit{Cur: 64000, Max: 64000})
fmt.Printf("========== %s: %d total clients, %d slow client(s), %d messages each ==========\n",
name, numSlowClients+numNormalClients, numSlowClients, numMessages)
ts := newTestSystem(t)
if err := ts.startServer(startServerTries); err != nil {
t.Errorf("Failed to start server: %s\n", err)
return
}
defer ts.server.Close()
slowClients := newTestClients(numSlowClients, true)
if err := ts.startClients(slowClients...); err != nil {
t.Errorf("Test failed: %s\n", err)
return
}
defer ts.killClients(slowClients...)
normalClients := newTestClients(numNormalClients, false)
if err := ts.startClients(normalClients...); err != nil {
t.Errorf("Test failed: %s\n", err)
return
}
defer ts.killClients(normalClients...)
// Give the server some time to register the clients before running the test.
time.Sleep(time.Duration(defaultStartDelay) * time.Millisecond)
if err := ts.runTest(numMessages, timeout, normalClients, slowClients, slowDelay); err != nil {
t.Error(err)
return
}
}
func getMaxOpenFiles(t *testing.T) int {
var limit syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
t.Fatal(err)
}
return int(limit.Cur)
}
func Init() {
mu.Lock()
defer mu.Unlock()
if inited {
log.Fatal("servenv.Init called second time")
}
inited = true
// Once you run as root, you pretty much destroy the chances of a
// non-privileged user starting the program correctly.
if uid := os.Getuid(); uid == 0 {
log.Fatalf("servenv.Init: running this as root makes no sense")
}
runtime.MemProfileRate = *memProfileRate
gomaxprocs := os.Getenv("GOMAXPROCS")
if gomaxprocs == "" {
gomaxprocs = "1"
}
// We used to set this limit directly, but you pretty much have to
// use a root account to allow increasing a limit reliably. Dropping
// privileges is also tricky. The best strategy is to make a shell
// script set up the limits as root and switch users before starting
// the server.
fdLimit := &syscall.Rlimit{}
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, fdLimit); err != nil {
log.Errorf("max-open-fds failed: %v", err)
}
fdl := stats.NewInt("MaxFds")
fdl.Set(int64(fdLimit.Cur))
onInitHooks.Fire()
}
// setOpenFilesLimit sets the open file limit in the kernel
// cur is the soft limit, max is the ceiling (or hard limit) for that limit
func (pm *ProcessManager) setOpenFilesLimit(cur, max uint64) error {
var rLimit syscall.Rlimit
// First check if the limits are already what we want
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return err
}
// If the current values are less than we want, set them
if rLimit.Cur < cur || rLimit.Max < max {
if cur > rLimit.Cur {
rLimit.Cur = cur
}
if max > rLimit.Max {
rLimit.Max = max
}
log.Infof("Setting open files limit (soft, hard) to (%v, %v)", rLimit.Cur, rLimit.Max)
err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return err
}
}
return nil
}
// SetLimits raises some process limits to values which allow dcrd and
// associated utilities to run.
func SetLimits() error {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return err
}
if rLimit.Cur > fileLimitWant {
return nil
}
if rLimit.Max < fileLimitMin {
err = fmt.Errorf("need at least %v file descriptors",
fileLimitMin)
return err
}
if rLimit.Max < fileLimitWant {
rLimit.Cur = rLimit.Max
} else {
rLimit.Cur = fileLimitWant
}
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
// try min value
rLimit.Cur = fileLimitMin
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
return err
}
}
return nil
}
func (dld *DataStoreLoader) calculateMaxOpenFilesPerShard() int {
var rlim syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim)
if err != nil {
dld.lg.Warnf("Unable to calculate maximum open files per shard: "+
"getrlimit failed: %s\n", err.Error())
return 0
}
// I think RLIMIT_NOFILE fits in 32 bits on all known operating systems,
// but there's no harm in being careful. 'int' in golang always holds at
// least 32 bits.
var maxFd int
if rlim.Cur > uint64(math.MaxInt32) {
maxFd = math.MaxInt32
} else {
maxFd = int(rlim.Cur)
}
if len(dld.shards) == 0 {
dld.lg.Warnf("Unable to calculate maximum open files per shard, " +
"since there are 0 shards configured.\n")
return 0
}
fdsPerShard := (maxFd - NON_DATASTORE_FD_MAX) / len(dld.shards)
if fdsPerShard < MIN_FDS_PER_SHARD {
dld.lg.Warnf("Expected to be able to use at least %d "+
"fds per shard, but we have %d shards and %d total fds to allocate, "+
"giving us only %d FDs per shard.", MIN_FDS_PER_SHARD,
len(dld.shards), maxFd-NON_DATASTORE_FD_MAX, fdsPerShard)
return 0
}
dld.lg.Infof("maxFd = %d. Setting maxFdPerShard = %d\n",
maxFd, fdsPerShard)
return fdsPerShard
}
// getFdLimit retrieves the number of file descriptors allowed to be opened by this
// process.
func getFdLimit() (int, error) {
var limit syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
return 0, err
}
return int(limit.Cur), nil
}
func main() {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
fmt.Println("Error Getting Rlimit ", err)
}
fmt.Print("Maximum FD per process: ")
fmt.Println(rLimit)
debug = flag.Bool("d", false, "Debug mode can be \"1\" for yes or \"0 for no")
tcp_port = flag.String("l", ":9090", "ip:port for listening or plain \":port\" for listening all IPs")
flag.Parse()
l, err := tproxy.TcpListen(*tcp_port)
if err != nil && *debug {
fmt.Fprintln(os.Stderr, err)
}
for {
s, err := l.Accept()
if err != nil {
//panic(err)
fmt.Println(err)
}
if *debug {
fmt.Println("starting connection from: " + (s.RemoteAddr()).String() + ", to: " + (s.LocalAddr()).String())
}
go handleConn(s, (s.LocalAddr()).String())
}
}
func FDLimit() (uint64, error) {
var rlimit syscall.Rlimit
if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit); err != nil {
return 0, err
}
return rlimit.Cur, nil
}
func TestMain(m *testing.M) {
var lim syscall.Rlimit
syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim)
lim.Cur = 1024000
lim.Max = 1024000
syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lim)
}
// upLimitToHard ups a resource limit identified
// by the resource argument to it's hard limit
// the returned error is either from syscall.(Get|Set)rlimit
func upLimitToHard(resource int) error {
var resLimit = new(syscall.Rlimit)
if err := syscall.Getrlimit(resource, resLimit); err != nil {
return err
}
resLimit.Cur = resLimit.Max
return syscall.Setrlimit(resource, resLimit)
}
// findUlimit uses a syscall to determine the value of `ulimit -v` on the command line.
// This is the amount of virtual memory that can be allocated to programs running in this shell.
// This will return 2^64 if `ulimit -v` is `unlimited`.
func (u linuxSystemFactFinder) findUlimit() (uint64, error) {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_AS, &rLimit)
if err != nil {
return 0, err
}
return rLimit.Max, err
}
func SetUlimit(number uint64) {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
fmt.Println("[Error]: Getting Rlimit ", err)
}
rLimit.Max = number
rLimit.Cur = number
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
fmt.Println("[Error]: Setting Rlimit ", err)
}
err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
fmt.Println("[Error]: Getting Rlimit ", err)
}
}
func ShowRlimit() {
var rLimit syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
if err != nil {
panic(fmt.Sprintf("Error Getting Rlimit '%s'", err))
}
fmt.Printf("starting rlimit.Cur = %d, rlimit.Max = %d\n", rLimit.Cur, rLimit.Max)
}
func getRlimitMax(resource int) int {
var rlimit syscall.Rlimit
if err := syscall.Getrlimit(resource, &rlimit); err == nil {
return int(rlimit.Max)
}
return 0
}
