les: implement request distributor, fix blocking issues (#3660)
* les: implement request distributor, fix blocking issues * core: moved header validation before chain mutex lock
This commit is contained in:
committed by
Felix Lange
parent
1c1dc0e0fc
commit
525116dbff
@ -94,14 +94,12 @@ func (peer *ClientNode) RequestProcessed(cost uint64) (bv, realCost uint64) {
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}
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type ServerNode struct {
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bufEstimate uint64
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lastTime mclock.AbsTime
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params *ServerParams
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sumCost uint64 // sum of req costs sent to this server
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pending map[uint64]uint64 // value = sumCost after sending the given req
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assignedRequest uint64 // when != 0, only the request with the given ID can be sent to this peer
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assignToken chan struct{} // send to this channel before assigning, read from it after deassigning
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lock sync.RWMutex
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bufEstimate uint64
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lastTime mclock.AbsTime
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params *ServerParams
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sumCost uint64 // sum of req costs sent to this server
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pending map[uint64]uint64 // value = sumCost after sending the given req
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lock sync.RWMutex
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}
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func NewServerNode(params *ServerParams) *ServerNode {
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@ -110,7 +108,6 @@ func NewServerNode(params *ServerParams) *ServerNode {
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lastTime: mclock.Now(),
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params: params,
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pending: make(map[uint64]uint64),
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assignToken: make(chan struct{}, 1),
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}
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}
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@ -127,94 +124,37 @@ func (peer *ServerNode) recalcBLE(time mclock.AbsTime) {
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}
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// safetyMargin is added to the flow control waiting time when estimated buffer value is low
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const safetyMargin = time.Millisecond * 200
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const safetyMargin = time.Millisecond
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func (peer *ServerNode) canSend(maxCost uint64) time.Duration {
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func (peer *ServerNode) canSend(maxCost uint64) (time.Duration, float64) {
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peer.recalcBLE(mclock.Now())
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maxCost += uint64(safetyMargin) * peer.params.MinRecharge / uint64(fcTimeConst)
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if maxCost > peer.params.BufLimit {
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maxCost = peer.params.BufLimit
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}
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if peer.bufEstimate >= maxCost {
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return 0
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return 0, float64(peer.bufEstimate-maxCost) / float64(peer.params.BufLimit)
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}
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return time.Duration((maxCost - peer.bufEstimate) * uint64(fcTimeConst) / peer.params.MinRecharge)
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return time.Duration((maxCost - peer.bufEstimate) * uint64(fcTimeConst) / peer.params.MinRecharge), 0
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}
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// CanSend returns the minimum waiting time required before sending a request
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// with the given maximum estimated cost
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func (peer *ServerNode) CanSend(maxCost uint64) time.Duration {
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// with the given maximum estimated cost. Second return value is the relative
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// estimated buffer level after sending the request (divided by BufLimit).
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func (peer *ServerNode) CanSend(maxCost uint64) (time.Duration, float64) {
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peer.lock.RLock()
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defer peer.lock.RUnlock()
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return peer.canSend(maxCost)
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}
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// AssignRequest tries to assign the server node to the given request, guaranteeing
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// that once it returns true, no request will be sent to the node before this one
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func (peer *ServerNode) AssignRequest(reqID uint64) bool {
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select {
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case peer.assignToken <- struct{}{}:
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default:
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return false
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}
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peer.lock.Lock()
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peer.assignedRequest = reqID
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peer.lock.Unlock()
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return true
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}
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// MustAssignRequest waits until the node can be assigned to the given request.
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// It is always guaranteed that assignments are released in a short amount of time.
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func (peer *ServerNode) MustAssignRequest(reqID uint64) {
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peer.assignToken <- struct{}{}
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peer.lock.Lock()
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peer.assignedRequest = reqID
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peer.lock.Unlock()
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}
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// DeassignRequest releases a request assignment in case the planned request
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// is not being sent.
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func (peer *ServerNode) DeassignRequest(reqID uint64) {
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peer.lock.Lock()
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if peer.assignedRequest == reqID {
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peer.assignedRequest = 0
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<-peer.assignToken
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}
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peer.lock.Unlock()
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}
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// IsAssigned returns true if the server node has already been assigned to a request
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// (note that this function returning false does not guarantee that you can assign a request
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// immediately afterwards, its only purpose is to help peer selection)
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func (peer *ServerNode) IsAssigned() bool {
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peer.lock.RLock()
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locked := peer.assignedRequest != 0
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peer.lock.RUnlock()
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return locked
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}
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// blocks until request can be sent
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func (peer *ServerNode) SendRequest(reqID, maxCost uint64) {
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// QueueRequest should be called when the request has been assigned to the given
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// server node, before putting it in the send queue. It is mandatory that requests
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// are sent in the same order as the QueueRequest calls are made.
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func (peer *ServerNode) QueueRequest(reqID, maxCost uint64) {
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peer.lock.Lock()
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defer peer.lock.Unlock()
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if peer.assignedRequest != reqID {
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peer.lock.Unlock()
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peer.MustAssignRequest(reqID)
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peer.lock.Lock()
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}
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peer.recalcBLE(mclock.Now())
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wait := peer.canSend(maxCost)
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for wait > 0 {
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peer.lock.Unlock()
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time.Sleep(wait)
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peer.lock.Lock()
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peer.recalcBLE(mclock.Now())
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wait = peer.canSend(maxCost)
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}
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peer.assignedRequest = 0
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<-peer.assignToken
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peer.bufEstimate -= maxCost
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peer.sumCost += maxCost
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if reqID >= 0 {
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@ -222,6 +162,8 @@ func (peer *ServerNode) SendRequest(reqID, maxCost uint64) {
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}
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}
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// GotReply adjusts estimated buffer value according to the value included in
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// the latest request reply.
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func (peer *ServerNode) GotReply(reqID, bv uint64) {
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peer.lock.Lock()
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@ -235,6 +177,10 @@ func (peer *ServerNode) GotReply(reqID, bv uint64) {
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return
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}
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delete(peer.pending, reqID)
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peer.bufEstimate = bv - (peer.sumCost - sc)
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cc := peer.sumCost - sc
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peer.bufEstimate = 0
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if bv > cc {
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peer.bufEstimate = bv - cc
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}
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peer.lastTime = mclock.Now()
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}
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