Ejemplo n.º 1
0
func handleApplied(slot uint64, idempotentChanges []store.Change) {

	relativeSlot := int(slot - store.InstructionStart())
	slots := store.InstructionSlots()

	origReq := slots[relativeSlot][0].ChangeRequest()
	chrequest := new(store.ChangeRequest)
	chrequest.RequestEntity = origReq.RequestEntity
	chrequest.RequestNode = origReq.RequestNode
	chrequest.RequestId = origReq.RequestId
	chrequest.Changeset = idempotentChanges

	connectionsLock.Lock()

	for _, conn := range connections {

		conn.lock.Lock()

		if conn.sendingBurst {
			sendInstructionData(conn, slot, chrequest)
		}

		conn.lock.Unlock()
	}

	connectionsLock.Unlock()

}
Ejemplo n.º 2
0
// Must be called from inside a transaction.
func makeRequest(changes []store.Change) *store.ChangeRequest {
	req := new(store.ChangeRequest)
	req.RequestEntity = uint64(config.Id())
	req.RequestNode = config.Id()
	req.RequestId = store.AllocateRequestId()
	req.Changeset = changes

	return req
}
Ejemplo n.º 3
0
func makeExtChangeRequest(intReq *coproto.ChangeRequest) *store.ChangeRequest {

	req := new(store.ChangeRequest)
	req.RequestEntity = *intReq.RequestEntity
	req.RequestNode = uint16(*intReq.RequestNode)
	req.RequestId = *intReq.RequestId

	req.Changeset = make([]store.Change, len(intReq.Changeset))
	for i, intCh := range intReq.Changeset {
		req.Changeset[i].TargetEntity = *intCh.TargetEntity
		req.Changeset[i].Key = *intCh.Key
		req.Changeset[i].Value = *intCh.Value
	}

	return req
}
Ejemplo n.º 4
0
// Handle a received change forward. Decides which node is responsible for it.
// Must only be called from the processing goroutine.
func processForward(forward *chproto.ChangeForward) {

	// If we are already trying to forward a change forward message with
	// the same requesting node and request ID, discard this message.
	if _, exists := getForwardTimeout(uint16(*forward.Request.RequestNode),
		*forward.Request.RequestId); exists {
		return
	}

	// Everything else in this function runs in a transaction.
	// We are read-only.
	store.StartTransaction()
	defer store.EndTransaction()

	// If this is a core node and this node stopped being leader less than
	// a Change Timeout Period ago, always add us to the ignore list.
	if config.IsCore() && !isIgnored(forward, config.Id()) {
		diff := time.Now().Sub(store.StoppedLeading())
		if diff < config.CHANGE_TIMEOUT_PERIOD {
			forward.Ignores = append(forward.Ignores,
				uint32(config.Id()))
		}
	}

	// If all core node IDs are in the forward's ignore list, discard it.
	if len(forward.Ignores) == len(config.CoreNodes()) {
		log.Print("shared/chrequest: dropped msg due to full ignores")
		return
	}

	// Otherwise, choose a potential leader node.
	// This is O(n^2) in the number of core nodes,
	// but we don't expect to have many.
	chosenNode := uint16(0)
	_, leader := store.Proposal()
	if leader != 0 && !isIgnored(forward, leader) {
		chosenNode = leader
	} else {
		for _, node := range config.CoreNodes() {
			if !isIgnored(forward, node) {
				chosenNode = node
				break
			}
		}
	}
	if chosenNode == 0 {
		// Shouldn't happen.
		log.Print("shared/chrequest: bug, " +
			"couldn't find candidate leader node")
		return
	}

	// If we are the selected leader, construct an external change request,
	// and send it on our change request channel.
	if chosenNode == config.Id() {
		intRequest := forward.Request
		chrequest := new(store.ChangeRequest)
		chrequest.RequestEntity = *intRequest.RequestEntity
		chrequest.RequestNode = uint16(*intRequest.RequestNode)
		chrequest.RequestId = *intRequest.RequestId
		chrequest.Changeset = make([]store.Change,
			len(intRequest.Changeset))

		for i, ch := range intRequest.Changeset {
			chrequest.Changeset[i].TargetEntity = *ch.TargetEntity
			chrequest.Changeset[i].Key = *ch.Key
			chrequest.Changeset[i].Value = *ch.Value
		}

		for _, cb := range changeCallbacks {
			cb(chrequest)
		}

		return
	}

	// Otherwise, we send it on to the selected leader,
	// add the selected leader to the ignore list,
	// and set a timeout to retry.
	sendForward(chosenNode, forward)
	forward.Ignores = append(forward.Ignores, uint32(chosenNode))
	addForwardTimeout(forward)
}
Ejemplo n.º 5
0
func handleInstructionData(f *followConn, content []byte) {
	store.StartTransaction()
	defer store.EndTransaction()
	f.lock.Lock()

	if f.closed {
		f.lock.Unlock()
		return
	}

	var msg fproto.InstructionData
	if err := proto.Unmarshal(content, &msg); err != nil {
		f.Close()
		f.lock.Unlock()
		return
	}

	if f.receivingBurst {
		f.waiting = append(f.waiting, &msg)
		f.lock.Unlock()
		return
	}

	// We need to unlock before we start mutating the store,
	// due to callbacks from the store package to elsewhere.
	f.lock.Unlock()

	// If we have a chosen instruction in this slot already,
	// or it is prior to our instruction start number,
	// discard this message.
	relativeSlot := int(*msg.Slot - store.InstructionStart())
	if relativeSlot < 0 {
		return
	}

	instructions := store.InstructionSlots()
	if relativeSlot < len(instructions) &&
		len(instructions[relativeSlot]) == 1 &&
		instructions[relativeSlot][0].IsChosen() {

		return
	}

	// Construct a store.ChangeRequest from our
	// internal ChangeRequest.
	chrequest := new(store.ChangeRequest)
	chrequest.RequestEntity = *msg.Request.RequestEntity
	chrequest.RequestNode = uint16(*msg.Request.RequestNode)
	chrequest.RequestId = *msg.Request.RequestId
	chrequest.Changeset = make([]store.Change,
		len(msg.Request.Changeset))

	for i, ch := range msg.Request.Changeset {
		chrequest.Changeset[i].TargetEntity = *ch.TargetEntity
		chrequest.Changeset[i].Key = *ch.Key
		chrequest.Changeset[i].Value = *ch.Value
	}

	// Add instruction value and immediately choose it.
	store.AddInstructionValue(*msg.Slot, chrequest).Choose()
}