filecoin技术架构分析五:filecoin源码分析之协议层心跳协议

我是先河系统CTO杨尉,欢迎大加关注的的Github: waynewyang,本文是filecoin技术架构分析系列文章第五章filecoin源码分析之协议层心跳协议。

源码信息

  • version
    • master分支 619b0eb1(2019年3月2日)
  • package
    • metrics
  • location
    • metrics/heartbeat.go
    • node/node.go

源码分析

数据结构

  • 定义心跳协议名称以及连接超时时间
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// HeartbeatProtocol is the libp2p protocol used for the heartbeat service
const (
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)
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// 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
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// 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
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      // HeartbeatServiceOption is the type of the heartbeat service's functional options.
      type HeartbeatServiceOption func(service *HeartbeatService)

方法

  • 获取心跳服务的stream实例
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// 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
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// 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
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// 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
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// 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
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// 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
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    // Connect will connects to `hbs.Config.BeatTarget` or returns an error
    func (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
    }

函数

  • 向心跳服务结构体传参,用于设置获取矿工地址函数
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// 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
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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。
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// NewHeartbeatService returns a HeartbeatService
func 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
}

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

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// 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
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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
}

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