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funcs.go
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funcs.go
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/*
*
* Copyright 2018 gRPC 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 channelz defines APIs for enabling channelz service, entry
// registration/deletion, and accessing channelz data. It also defines channelz
// metric struct formats.
//
// All APIs in this package are experimental.
package channelz
import (
"fmt"
"sort"
"sync"
"sync/atomic"
"time"
"google.golang.org/grpc/grpclog"
)
const (
defaultMaxTraceEntry int32 = 30
)
var (
db dbWrapper
idGen idGenerator
// EntryPerPage defines the number of channelz entries to be shown on a web page.
EntryPerPage = int64(50)
curState int32
maxTraceEntry = defaultMaxTraceEntry
)
// TurnOn turns on channelz data collection.
func TurnOn() {
if !IsOn() {
NewChannelzStorage()
atomic.StoreInt32(&curState, 1)
}
}
// IsOn returns whether channelz data collection is on.
func IsOn() bool {
return atomic.CompareAndSwapInt32(&curState, 1, 1)
}
// SetMaxTraceEntry sets maximum number of trace entry per entity (i.e. channel/subchannel).
// Setting it to 0 will disable channel tracing.
func SetMaxTraceEntry(i int32) {
atomic.StoreInt32(&maxTraceEntry, i)
}
// ResetMaxTraceEntryToDefault resets the maximum number of trace entry per entity to default.
func ResetMaxTraceEntryToDefault() {
atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
}
func getMaxTraceEntry() int {
i := atomic.LoadInt32(&maxTraceEntry)
return int(i)
}
// dbWarpper wraps around a reference to internal channelz data storage, and
// provide synchronized functionality to set and get the reference.
type dbWrapper struct {
mu sync.RWMutex
DB *channelMap
}
func (d *dbWrapper) set(db *channelMap) {
d.mu.Lock()
d.DB = db
d.mu.Unlock()
}
func (d *dbWrapper) get() *channelMap {
d.mu.RLock()
defer d.mu.RUnlock()
return d.DB
}
// NewChannelzStorage initializes channelz data storage and id generator.
//
// This function returns a cleanup function to wait for all channelz state to be reset by the
// grpc goroutines when those entities get closed. By using this cleanup function, we make sure tests
// don't mess up each other, i.e. lingering goroutine from previous test doing entity removal happen
// to remove some entity just register by the new test, since the id space is the same.
//
// Note: This function is exported for testing purpose only. User should not call
// it in most cases.
func NewChannelzStorage() (cleanup func() error) {
db.set(&channelMap{
topLevelChannels: make(map[int64]struct{}),
channels: make(map[int64]*channel),
listenSockets: make(map[int64]*listenSocket),
normalSockets: make(map[int64]*normalSocket),
servers: make(map[int64]*server),
subChannels: make(map[int64]*subChannel),
})
idGen.reset()
return func() error {
var err error
cm := db.get()
if cm == nil {
return nil
}
for i := 0; i < 1000; i++ {
cm.mu.Lock()
if len(cm.topLevelChannels) == 0 && len(cm.servers) == 0 && len(cm.channels) == 0 && len(cm.subChannels) == 0 && len(cm.listenSockets) == 0 && len(cm.normalSockets) == 0 {
cm.mu.Unlock()
// all things stored in the channelz map have been cleared.
return nil
}
cm.mu.Unlock()
time.Sleep(10 * time.Millisecond)
}
cm.mu.Lock()
err = fmt.Errorf("after 10s the channelz map has not been cleaned up yet, topchannels: %d, servers: %d, channels: %d, subchannels: %d, listen sockets: %d, normal sockets: %d", len(cm.topLevelChannels), len(cm.servers), len(cm.channels), len(cm.subChannels), len(cm.listenSockets), len(cm.normalSockets))
cm.mu.Unlock()
return err
}
}
// GetTopChannels returns a slice of top channel's ChannelMetric, along with a
// boolean indicating whether there's more top channels to be queried for.
//
// The arg id specifies that only top channel with id at or above it will be included
// in the result. The returned slice is up to a length of the arg maxResults or
// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
func GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
return db.get().GetTopChannels(id, maxResults)
}
// GetServers returns a slice of server's ServerMetric, along with a
// boolean indicating whether there's more servers to be queried for.
//
// The arg id specifies that only server with id at or above it will be included
// in the result. The returned slice is up to a length of the arg maxResults or
// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
func GetServers(id int64, maxResults int64) ([]*ServerMetric, bool) {
return db.get().GetServers(id, maxResults)
}
// GetServerSockets returns a slice of server's (identified by id) normal socket's
// SocketMetric, along with a boolean indicating whether there's more sockets to
// be queried for.
//
// The arg startID specifies that only sockets with id at or above it will be
// included in the result. The returned slice is up to a length of the arg maxResults
// or EntryPerPage if maxResults is zero, and is sorted in ascending id order.
func GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
return db.get().GetServerSockets(id, startID, maxResults)
}
// GetChannel returns the ChannelMetric for the channel (identified by id).
func GetChannel(id int64) *ChannelMetric {
return db.get().GetChannel(id)
}
// GetSubChannel returns the SubChannelMetric for the subchannel (identified by id).
func GetSubChannel(id int64) *SubChannelMetric {
return db.get().GetSubChannel(id)
}
// GetSocket returns the SocketInternalMetric for the socket (identified by id).
func GetSocket(id int64) *SocketMetric {
return db.get().GetSocket(id)
}
// GetServer returns the ServerMetric for the server (identified by id).
func GetServer(id int64) *ServerMetric {
return db.get().GetServer(id)
}
// RegisterChannel registers the given channel c in channelz database with ref
// as its reference name, and add it to the child list of its parent (identified
// by pid). pid = 0 means no parent. It returns the unique channelz tracking id
// assigned to this channel.
func RegisterChannel(c Channel, pid int64, ref string) int64 {
id := idGen.genID()
cn := &channel{
refName: ref,
c: c,
subChans: make(map[int64]string),
nestedChans: make(map[int64]string),
id: id,
pid: pid,
trace: &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
}
if pid == 0 {
db.get().addChannel(id, cn, true, pid, ref)
} else {
db.get().addChannel(id, cn, false, pid, ref)
}
return id
}
// RegisterSubChannel registers the given channel c in channelz database with ref
// as its reference name, and add it to the child list of its parent (identified
// by pid). It returns the unique channelz tracking id assigned to this subchannel.
func RegisterSubChannel(c Channel, pid int64, ref string) int64 {
if pid == 0 {
grpclog.Error("a SubChannel's parent id cannot be 0")
return 0
}
id := idGen.genID()
sc := &subChannel{
refName: ref,
c: c,
sockets: make(map[int64]string),
id: id,
pid: pid,
trace: &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
}
db.get().addSubChannel(id, sc, pid, ref)
return id
}
// RegisterServer registers the given server s in channelz database. It returns
// the unique channelz tracking id assigned to this server.
func RegisterServer(s Server, ref string) int64 {
id := idGen.genID()
svr := &server{
refName: ref,
s: s,
sockets: make(map[int64]string),
listenSockets: make(map[int64]string),
id: id,
}
db.get().addServer(id, svr)
return id
}
// RegisterListenSocket registers the given listen socket s in channelz database
// with ref as its reference name, and add it to the child list of its parent
// (identified by pid). It returns the unique channelz tracking id assigned to
// this listen socket.
func RegisterListenSocket(s Socket, pid int64, ref string) int64 {
if pid == 0 {
grpclog.Error("a ListenSocket's parent id cannot be 0")
return 0
}
id := idGen.genID()
ls := &listenSocket{refName: ref, s: s, id: id, pid: pid}
db.get().addListenSocket(id, ls, pid, ref)
return id
}
// RegisterNormalSocket registers the given normal socket s in channelz database
// with ref as its reference name, and add it to the child list of its parent
// (identified by pid). It returns the unique channelz tracking id assigned to
// this normal socket.
func RegisterNormalSocket(s Socket, pid int64, ref string) int64 {
if pid == 0 {
grpclog.Error("a NormalSocket's parent id cannot be 0")
return 0
}
id := idGen.genID()
ns := &normalSocket{refName: ref, s: s, id: id, pid: pid}
db.get().addNormalSocket(id, ns, pid, ref)
return id
}
// RemoveEntry removes an entry with unique channelz trakcing id to be id from
// channelz database.
func RemoveEntry(id int64) {
db.get().removeEntry(id)
}
// TraceEventDesc is what the caller of AddTraceEvent should provide to describe the event to be added
// to the channel trace.
// The Parent field is optional. It is used for event that will be recorded in the entity's parent
// trace also.
type TraceEventDesc struct {
Desc string
Severity Severity
Parent *TraceEventDesc
}
// AddTraceEvent adds trace related to the entity with specified id, using the provided TraceEventDesc.
func AddTraceEvent(id int64, desc *TraceEventDesc) {
if getMaxTraceEntry() == 0 {
return
}
db.get().traceEvent(id, desc)
}
// channelMap is the storage data structure for channelz.
// Methods of channelMap can be divided in two two categories with respect to locking.
// 1. Methods acquire the global lock.
// 2. Methods that can only be called when global lock is held.
// A second type of method need always to be called inside a first type of method.
type channelMap struct {
mu sync.RWMutex
topLevelChannels map[int64]struct{}
servers map[int64]*server
channels map[int64]*channel
subChannels map[int64]*subChannel
listenSockets map[int64]*listenSocket
normalSockets map[int64]*normalSocket
}
func (c *channelMap) addServer(id int64, s *server) {
c.mu.Lock()
s.cm = c
c.servers[id] = s
c.mu.Unlock()
}
func (c *channelMap) addChannel(id int64, cn *channel, isTopChannel bool, pid int64, ref string) {
c.mu.Lock()
cn.cm = c
cn.trace.cm = c
c.channels[id] = cn
if isTopChannel {
c.topLevelChannels[id] = struct{}{}
} else {
c.findEntry(pid).addChild(id, cn)
}
c.mu.Unlock()
}
func (c *channelMap) addSubChannel(id int64, sc *subChannel, pid int64, ref string) {
c.mu.Lock()
sc.cm = c
sc.trace.cm = c
c.subChannels[id] = sc
c.findEntry(pid).addChild(id, sc)
c.mu.Unlock()
}
func (c *channelMap) addListenSocket(id int64, ls *listenSocket, pid int64, ref string) {
c.mu.Lock()
ls.cm = c
c.listenSockets[id] = ls
c.findEntry(pid).addChild(id, ls)
c.mu.Unlock()
}
func (c *channelMap) addNormalSocket(id int64, ns *normalSocket, pid int64, ref string) {
c.mu.Lock()
ns.cm = c
c.normalSockets[id] = ns
c.findEntry(pid).addChild(id, ns)
c.mu.Unlock()
}
// removeEntry triggers the removal of an entry, which may not indeed delete the entry, if it has to
// wait on the deletion of its children and until no other entity's channel trace references it.
// It may lead to a chain of entry deletion. For example, deleting the last socket of a gracefully
// shutting down server will lead to the server being also deleted.
func (c *channelMap) removeEntry(id int64) {
c.mu.Lock()
c.findEntry(id).triggerDelete()
c.mu.Unlock()
}
// c.mu must be held by the caller
func (c *channelMap) decrTraceRefCount(id int64) {
e := c.findEntry(id)
if v, ok := e.(tracedChannel); ok {
v.decrTraceRefCount()
e.deleteSelfIfReady()
}
}
// c.mu must be held by the caller.
func (c *channelMap) findEntry(id int64) entry {
var v entry
var ok bool
if v, ok = c.channels[id]; ok {
return v
}
if v, ok = c.subChannels[id]; ok {
return v
}
if v, ok = c.servers[id]; ok {
return v
}
if v, ok = c.listenSockets[id]; ok {
return v
}
if v, ok = c.normalSockets[id]; ok {
return v
}
return &dummyEntry{idNotFound: id}
}
// c.mu must be held by the caller
// deleteEntry simply deletes an entry from the channelMap. Before calling this
// method, caller must check this entry is ready to be deleted, i.e removeEntry()
// has been called on it, and no children still exist.
// Conditionals are ordered by the expected frequency of deletion of each entity
// type, in order to optimize performance.
func (c *channelMap) deleteEntry(id int64) {
var ok bool
if _, ok = c.normalSockets[id]; ok {
delete(c.normalSockets, id)
return
}
if _, ok = c.subChannels[id]; ok {
delete(c.subChannels, id)
return
}
if _, ok = c.channels[id]; ok {
delete(c.channels, id)
delete(c.topLevelChannels, id)
return
}
if _, ok = c.listenSockets[id]; ok {
delete(c.listenSockets, id)
return
}
if _, ok = c.servers[id]; ok {
delete(c.servers, id)
return
}
}
func (c *channelMap) traceEvent(id int64, desc *TraceEventDesc) {
c.mu.Lock()
child := c.findEntry(id)
childTC, ok := child.(tracedChannel)
if !ok {
c.mu.Unlock()
return
}
childTC.getChannelTrace().append(&TraceEvent{Desc: desc.Desc, Severity: desc.Severity, Timestamp: time.Now()})
if desc.Parent != nil {
parent := c.findEntry(child.getParentID())
var chanType RefChannelType
switch child.(type) {
case *channel:
chanType = RefChannel
case *subChannel:
chanType = RefSubChannel
}
if parentTC, ok := parent.(tracedChannel); ok {
parentTC.getChannelTrace().append(&TraceEvent{
Desc: desc.Parent.Desc,
Severity: desc.Parent.Severity,
Timestamp: time.Now(),
RefID: id,
RefName: childTC.getRefName(),
RefType: chanType,
})
childTC.incrTraceRefCount()
}
}
c.mu.Unlock()
}
type int64Slice []int64
func (s int64Slice) Len() int { return len(s) }
func (s int64Slice) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s int64Slice) Less(i, j int) bool { return s[i] < s[j] }
func copyMap(m map[int64]string) map[int64]string {
n := make(map[int64]string)
for k, v := range m {
n[k] = v
}
return n
}
func min(a, b int64) int64 {
if a < b {
return a
}
return b
}
func (c *channelMap) GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
if maxResults <= 0 {
maxResults = EntryPerPage
}
c.mu.RLock()
l := int64(len(c.topLevelChannels))
ids := make([]int64, 0, l)
cns := make([]*channel, 0, min(l, maxResults))
for k := range c.topLevelChannels {
ids = append(ids, k)
}
sort.Sort(int64Slice(ids))
idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
count := int64(0)
var end bool
var t []*ChannelMetric
for i, v := range ids[idx:] {
if count == maxResults {
break
}
if cn, ok := c.channels[v]; ok {
cns = append(cns, cn)
t = append(t, &ChannelMetric{
NestedChans: copyMap(cn.nestedChans),
SubChans: copyMap(cn.subChans),
})
count++
}
if i == len(ids[idx:])-1 {
end = true
break
}
}
c.mu.RUnlock()
if count == 0 {
end = true
}
for i, cn := range cns {
t[i].ChannelData = cn.c.ChannelzMetric()
t[i].ID = cn.id
t[i].RefName = cn.refName
t[i].Trace = cn.trace.dumpData()
}
return t, end
}
func (c *channelMap) GetServers(id, maxResults int64) ([]*ServerMetric, bool) {
if maxResults <= 0 {
maxResults = EntryPerPage
}
c.mu.RLock()
l := int64(len(c.servers))
ids := make([]int64, 0, l)
ss := make([]*server, 0, min(l, maxResults))
for k := range c.servers {
ids = append(ids, k)
}
sort.Sort(int64Slice(ids))
idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
count := int64(0)
var end bool
var s []*ServerMetric
for i, v := range ids[idx:] {
if count == maxResults {
break
}
if svr, ok := c.servers[v]; ok {
ss = append(ss, svr)
s = append(s, &ServerMetric{
ListenSockets: copyMap(svr.listenSockets),
})
count++
}
if i == len(ids[idx:])-1 {
end = true
break
}
}
c.mu.RUnlock()
if count == 0 {
end = true
}
for i, svr := range ss {
s[i].ServerData = svr.s.ChannelzMetric()
s[i].ID = svr.id
s[i].RefName = svr.refName
}
return s, end
}
func (c *channelMap) GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
if maxResults <= 0 {
maxResults = EntryPerPage
}
var svr *server
var ok bool
c.mu.RLock()
if svr, ok = c.servers[id]; !ok {
// server with id doesn't exist.
c.mu.RUnlock()
return nil, true
}
svrskts := svr.sockets
l := int64(len(svrskts))
ids := make([]int64, 0, l)
sks := make([]*normalSocket, 0, min(l, maxResults))
for k := range svrskts {
ids = append(ids, k)
}
sort.Sort(int64Slice(ids))
idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= startID })
count := int64(0)
var end bool
for i, v := range ids[idx:] {
if count == maxResults {
break
}
if ns, ok := c.normalSockets[v]; ok {
sks = append(sks, ns)
count++
}
if i == len(ids[idx:])-1 {
end = true
break
}
}
c.mu.RUnlock()
if count == 0 {
end = true
}
var s []*SocketMetric
for _, ns := range sks {
sm := &SocketMetric{}
sm.SocketData = ns.s.ChannelzMetric()
sm.ID = ns.id
sm.RefName = ns.refName
s = append(s, sm)
}
return s, end
}
func (c *channelMap) GetChannel(id int64) *ChannelMetric {
cm := &ChannelMetric{}
var cn *channel
var ok bool
c.mu.RLock()
if cn, ok = c.channels[id]; !ok {
// channel with id doesn't exist.
c.mu.RUnlock()
return nil
}
cm.NestedChans = copyMap(cn.nestedChans)
cm.SubChans = copyMap(cn.subChans)
// cn.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of cn.c when
// holding the lock to prevent potential data race.
chanCopy := cn.c
c.mu.RUnlock()
cm.ChannelData = chanCopy.ChannelzMetric()
cm.ID = cn.id
cm.RefName = cn.refName
cm.Trace = cn.trace.dumpData()
return cm
}
func (c *channelMap) GetSubChannel(id int64) *SubChannelMetric {
cm := &SubChannelMetric{}
var sc *subChannel
var ok bool
c.mu.RLock()
if sc, ok = c.subChannels[id]; !ok {
// subchannel with id doesn't exist.
c.mu.RUnlock()
return nil
}
cm.Sockets = copyMap(sc.sockets)
// sc.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of sc.c when
// holding the lock to prevent potential data race.
chanCopy := sc.c
c.mu.RUnlock()
cm.ChannelData = chanCopy.ChannelzMetric()
cm.ID = sc.id
cm.RefName = sc.refName
cm.Trace = sc.trace.dumpData()
return cm
}
func (c *channelMap) GetSocket(id int64) *SocketMetric {
sm := &SocketMetric{}
c.mu.RLock()
if ls, ok := c.listenSockets[id]; ok {
c.mu.RUnlock()
sm.SocketData = ls.s.ChannelzMetric()
sm.ID = ls.id
sm.RefName = ls.refName
return sm
}
if ns, ok := c.normalSockets[id]; ok {
c.mu.RUnlock()
sm.SocketData = ns.s.ChannelzMetric()
sm.ID = ns.id
sm.RefName = ns.refName
return sm
}
c.mu.RUnlock()
return nil
}
func (c *channelMap) GetServer(id int64) *ServerMetric {
sm := &ServerMetric{}
var svr *server
var ok bool
c.mu.RLock()
if svr, ok = c.servers[id]; !ok {
c.mu.RUnlock()
return nil
}
sm.ListenSockets = copyMap(svr.listenSockets)
c.mu.RUnlock()
sm.ID = svr.id
sm.RefName = svr.refName
sm.ServerData = svr.s.ChannelzMetric()
return sm
}
type idGenerator struct {
id int64
}
func (i *idGenerator) reset() {
atomic.StoreInt64(&i.id, 0)
}
func (i *idGenerator) genID() int64 {
return atomic.AddInt64(&i.id, 1)
}