本文作者：先河系统杨尉；原创作品，转载请注明出处
目录
5 filecoin源码协议层分析之心跳协议
5.2.1 数据结构
5.2.2 方法
5.2.3 函数
5.2.4 实例化及业务逻辑
5.1 源码信息
5.2 源码分析
5.1 源码信息
version
master分支 619b0eb1（2019年３月２日）
package
metrics
location
metrics/heartbeat.go
node/node.go
5.2 源码分析
5.2.1 数据结构
定义心跳协议名称以及连接超时时间
// HeartbeatProtocol is the libp2p protocol used for the heartbeat serviceconst ( HeartbeatProtocol = "fil/heartbeat/1.0.0" // Minutes to wait before logging connection failure at ERROR level connectionFailureErrorLogPeriodMinutes = 10 * time.Minute )
定义心跳信息结构
节点的区块头
节点的区块高度
节点的昵称
是否在区块同步中（ＴＯＤＯ）
矿工地址（如果没有挖矿，这里为零地址）
// Heartbeat contains the information required to determine the current state of a node.// Heartbeats are used for aggregating information about nodes in a log aggregator// to support alerting and devnet visualization.type Heartbeat struct {
// Head represents the heaviest tipset the nodes is mining on
Head string
// Height represents the current height of the Tipset
Height uint64 // Nickname is the nickname given to the filecoin node by the user
Nickname string
// TODO: add when implemented
// Syncing is `true` iff the node is currently syncing its chain with the network.
// Syncing bool
// Address of this node's active miner. Can be empty - will return the zero address
MinerAddress address.Address
}心跳服务结构体
主机结构体：对应libp2p主机
心跳配置
区块头获取
挖矿地址获取
stream锁
stream
// HeartbeatService is responsible for sending heartbeats.type HeartbeatService struct {
Host host.Host
Config *config.HeartbeatConfig // A function that returns the heaviest tipset
HeadGetter func() types.TipSet // A function that returns the miner's address
MinerAddressGetter func() address.Address
streamMu sync.Mutex
stream net.Stream
}定义心跳服务Option函数
函数入参为心跳服务结构体,主要用于对心跳服务结构体传参或者解析
// HeartbeatServiceOption is the type of the heartbeat service's functional options.type HeartbeatServiceOption func(service *HeartbeatService)
5.2.2 方法
获取心跳服务的stream实例
// Stream returns the HeartbeatService stream. Safe for concurrent access.// Stream is a libp2p connection that heartbeat messages are sent over to an aggregator.func (hbs *HeartbeatService) Stream() net.Stream {
hbs.streamMu.Lock()
defer hbs.streamMu.Unlock() return hbs.stream
}设置心跳服务的stream实例
// SetStream sets the stream on the HeartbeatService. Safe for concurrent access.func (hbs *HeartbeatService) SetStream(s net.Stream) {
hbs.streamMu.Lock()
defer hbs.streamMu.Unlock()
hbs.stream = s
}定时确认连接性，并调用运行心跳服务
// Start starts the heartbeat service by, starting the connection loop. The connection// loop will attempt to connected to the aggregator service, once a successful// connection is made with the aggregator service hearbeats will be sent to it.// If the connection is broken the heartbeat service will attempt to reconnect via// the connection loop. Start will not return until context `ctx` is 'Done'.func (hbs *HeartbeatService) Start(ctx context.Context) { log.Debug("starting heartbeat service")
rd, err := time.ParseDuration(hbs.Config.ReconnectPeriod) if err != nil { log.Errorf("invalid heartbeat reconnectPeriod: %s", err) return
} //启动重连定时器
reconTicker := time.NewTicker(rd)
defer reconTicker.Stop() // Timestamp of the first connection failure since the last successful connection.
// Zero initially and while connected.
var failedAt time.Time // Timestamp of the last ERROR log (or of failure, before the first ERROR log).
var erroredAt time.Time for {
select { case <-ctx.Done(): return
case <-reconTicker.C: //重连定时周期到，重新连接
if err := hbs.Connect(ctx); err != nil { // Logs once as a warning immediately on failure, then as error every 10 minutes.
now := time.Now()
logfn := log.Debugf if failedAt.IsZero() { // First failure since connection
failedAt = now
erroredAt = failedAt // Start the timer on raising to ERROR level
logfn = log.Warningf
} else if now.Sub(erroredAt) > connectionFailureErrorLogPeriodMinutes {
logfn = log.Errorf
erroredAt = now // Reset the timer
}
failureDuration := now.Sub(failedAt)
logfn("Heartbeat service failed to connect for %s: %s", failureDuration, err) // failed to connect, continue reconnect loop
continue
}
failedAt = time.Time{} // we connected, send heartbeats!
// Run will block until it fails to send a heartbeat.
//如果连接成功，运行心跳服务
if err := hbs.Run(ctx); err != nil { log.Warning("disconnecting from aggregator, failed to send heartbeat") continue
}
}
}
}运行心跳服务
// Run is called once the heartbeat service connects to the aggregator. Run// send the actual heartbeat. Run will block until `ctx` is 'Done`. An error will// be returned if Run encounters an error when sending the heartbeat and the connection// to the aggregator will be closed.func (hbs *HeartbeatService) Run(ctx context.Context) error {
bd, err := time.ParseDuration(hbs.Config.BeatPeriod) if err != nil {
log.Errorf("invalid heartbeat beatPeriod: %s", err) return err
} //启动心跳定时器
beatTicker := time.NewTicker(bd)
defer beatTicker.Stop() //通过encoder进行流写入
// TODO use cbor instead of json
encoder := json.NewEncoder(hbs.stream) for {
select { case <-ctx.Done(): return nil
case <-beatTicker.C: //心跳定时周期到，调用Beat方法获取心跳参数
hb := hbs.Beat() //写入流，发起心跳
if err := encoder.Encode(hb); err != nil { //发生错误会关闭流连接
hbs.stream.Conn().Close() // nolint: errcheck
return err
}
}
}
}获取心跳参数
// Beat will create a heartbeat.func (hbs *HeartbeatService) Beat() Heartbeat {
nick := hbs.Config.Nickname
ts := hbs.HeadGetter()
tipset := ts.ToSortedCidSet().String()
height, err := ts.Height() if err != nil { log.Warningf("heartbeat service failed to get chain height: %s", err)
}
addr := hbs.MinerAddressGetter() return Heartbeat{
Head: tipset,
Height: height,
Nickname: nick,
MinerAddress: addr,
}
}心跳流连接
// Connect will connects to `hbs.Config.BeatTarget` or returns an errorfunc (hbs *HeartbeatService) Connect(ctx context.Context) error {
log.Debugf("Heartbeat service attempting to connect, targetAddress: %s", hbs.Config.BeatTarget)
targetMaddr, err := ma.NewMultiaddr(hbs.Config.BeatTarget) if err != nil { return err
}
pid, err := targetMaddr.ValueForProtocol(ma.P_P2P) if err != nil { return err
}
peerid, err := peer.IDB58Decode(pid) if err != nil { return err
} // Decapsulate the /p2p/<peerID> part from the target
// /ip4/<a.b.c.d>/p2p/<peer> becomes /ip4/<a.b.c.d>
targetPeerAddr, _ := ma.NewMultiaddr(
fmt.Sprintf("/p2p/%s", peer.IDB58Encode(peerid)))
targetAddr := targetMaddr.Decapsulate(targetPeerAddr)
hbs.Host.Peerstore().AddAddr(peerid, targetAddr, pstore.PermanentAddrTTL) // 建立心跳服务流
s, err := hbs.Host.NewStream(ctx, peerid, HeartbeatProtocol) if err != nil {
log.Debugf("failed to open stream, peerID: %s, targetAddr: %s %s", peerid, targetAddr, err) return err
}
log.Infof("successfully to open stream, peerID: %s, targetAddr: %s", peerid, targetAddr) //设置流函数
hbs.SetStream(s) return nil}5.2.3 函数
向心跳服务结构体传参,用于设置获取矿工地址函数
// WithMinerAddressGetter returns an option that can be used to set the miner address getter.func WithMinerAddressGetter(ag func() address.Address) HeartbeatServiceOption { return func(service *HeartbeatService) {
service.MinerAddressGetter = ag
}
}获取默认的矿工地址
func defaultMinerAddressGetter() address.Address { return address.Address{}
}实例化心跳服务,具体的实例化在node包中实现。
// NewHeartbeatService returns a HeartbeatServicefunc NewHeartbeatService(h host.Host, hbc *config.HeartbeatConfig, hg func() types.TipSet, options ...HeartbeatServiceOption) *HeartbeatService {
srv := &HeartbeatService{
Host: h,
Config: hbc,
HeadGetter: hg,
MinerAddressGetter: defaultMinerAddressGetter,
} // 设置心跳服务的获取矿工属性,这会覆盖到上面设置的默认矿工地址
for _, option := range options {
option(srv)
} return srv
}5.2.4 实例化及业务逻辑
主要由node调用,location:node/node.go,主要逻辑如下
在node的启动方法中，调用node.setupHeartbeatServices方法，建立心跳服务
// Start boots up the node.func (node *Node) Start(ctx context.Context) error {
...... if err := node.setupHeartbeatServices(ctx); err != nil { return errors.Wrap(err, "failed to start heartbeat services")
} return nil}建立心跳服务,具体见如下注释
func (node *Node) setupHeartbeatServices(ctx context.Context) error { // 设置“矿工地址获取函数”
mag := func() address.Address {
addr, err := node.miningAddress() // the only error miningAddress() returns is ErrNoMinerAddress.
// if there is no configured miner address, simply send a zero
// address across the wire.
if err != nil { return address.Address{}
} return addr
} // 存在心跳目标的时候，实例化心跳服务实例
// start the primary heartbeat service
if len(node.Repo.Config().Heartbeat.BeatTarget) > 0 { //调用metrics包中的建立心跳服务实例、以及启动心跳服务实例方法
hbs := metrics.NewHeartbeatService(node.Host(), node.Repo.Config().Heartbeat, node.ChainReader.Head, metrics.WithMinerAddressGetter(mag))
go hbs.Start(ctx)
} // 确认是否用户有通过环境变量配置额外的心跳告警服务（自定义指向其他节点），根据用户配置的数目，拉起对应的多线程心跳服务。
// check if we want to connect to an alert service. An alerting service is a heartbeat
// service that can trigger alerts based on the contents of heatbeats.
if alertTarget := os.Getenv("FIL_HEARTBEAT_ALERTS"); len(alertTarget) > 0 {
ahbs := metrics.NewHeartbeatService(node.Host(), &config.HeartbeatConfig{
BeatTarget: alertTarget,
BeatPeriod: "10s",
ReconnectPeriod: "10s",
Nickname: node.Repo.Config().Heartbeat.Nickname,
}, node.ChainReader.Head, metrics.WithMinerAddressGetter(mag))
go ahbs.Start(ctx)
} return nil}
作者：杨尉
链接：https://www.jianshu.com/p/51697f7beedf
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