コード例 #1
0
ファイル: groups.go プロジェクト: dgraph-io/dgraph
// MembershipUpdateAfter generates the Flatbuffer response containing all the
// membership updates after the provided raft index.
func (g *groupi) MembershipUpdateAfter(ridx uint64) *task.MembershipUpdate {
	g.RLock()
	defer g.RUnlock()

	maxIdx := ridx
	out := new(task.MembershipUpdate)

	for gid, peers := range g.all {
		for _, s := range peers.list {
			if s.RaftIdx <= ridx {
				continue
			}
			if s.RaftIdx > maxIdx {
				maxIdx = s.RaftIdx
			}
			out.Members = append(out.Members,
				&task.Membership{
					Leader:  s.Leader,
					Id:      s.NodeId,
					GroupId: gid,
					Addr:    s.Addr,
				})
		}
	}

	out.LastUpdate = maxIdx
	return out
}
コード例 #2
0
ファイル: groups.go プロジェクト: dgraph-io/dgraph
// syncMemberships needs to be called in an periodic loop.
// How syncMemberships works:
// - Each server iterates over all the nodes it's serving, present in local.
// - If serving group zero, propose membership status updates directly via RAFT.
// - Otherwise, generates a membership update, which includes status of all serving nodes.
// - Check if it has address of a server from group zero. If so, use that.
// - Otherwise, use the peer information passed down via flags.
// - Send update via UpdateMembership call to the peer.
// - If the peer doesn't serve group zero, it would return back a redirect with the right address.
// - Otherwise, it would iterate over the memberships, check for duplicates, and apply updates.
// - Once iteration is over without errors, it would return back all new updates.
// - These updates are then applied to groups().all state via applyMembershipUpdate.
func (g *groupi) syncMemberships() {
	if g.ServesGroup(0) {
		// This server serves group zero.
		g.RLock()
		defer g.RUnlock()
		for _, n := range g.local {
			rc := n.raftContext
			if g.duplicate(rc.Group, rc.Id, rc.Addr, n.AmLeader()) {
				continue
			}

			go func(rc *task.RaftContext, amleader bool) {
				mm := &task.Membership{
					Leader:  amleader,
					Id:      rc.Id,
					GroupId: rc.Group,
					Addr:    rc.Addr,
				}
				zero := g.Node(0)
				x.AssertTruef(zero != nil, "Expected node 0")
				if err := zero.ProposeAndWait(zero.ctx, &task.Proposal{Membership: mm}); err != nil {
					x.TraceError(g.ctx, err)
				}
			}(rc, n.AmLeader())
		}
		return
	}

	// This server doesn't serve group zero.
	// Generate membership update of all local nodes.
	var mu task.MembershipUpdate
	{
		g.RLock()
		for _, n := range g.local {
			rc := n.raftContext
			mu.Members = append(mu.Members,
				&task.Membership{
					Leader:  n.AmLeader(),
					Id:      rc.Id,
					GroupId: rc.Group,
					Addr:    rc.Addr,
				})
		}
		mu.LastUpdate = g.lastUpdate
		g.RUnlock()
	}

	// Send an update to peer.
	var pl *pool
	addr := g.AnyServer(0)

UPDATEMEMBERSHIP:
	if len(addr) > 0 {
		pl = pools().get(addr)
	} else {
		pl = pools().any()
	}
	conn, err := pl.Get()
	if err == errNoConnection {
		fmt.Println("Unable to sync memberships. No valid connection")
		return
	}
	x.Check(err)
	defer pl.Put(conn)

	c := NewWorkerClient(conn)
	update, err := c.UpdateMembership(g.ctx, &mu)
	if err != nil {
		x.TraceError(g.ctx, err)
		return
	}

	// Check if we got a redirect.
	if update.Redirect {
		addr = update.RedirectAddr
		if len(addr) == 0 {
			return
		}
		fmt.Printf("Got redirect for: %q\n", addr)
		pools().connect(addr)
		goto UPDATEMEMBERSHIP
	}

	var lu uint64
	for _, mm := range update.Members {
		g.applyMembershipUpdate(update.LastUpdate, mm)
		if lu < update.LastUpdate {
			lu = update.LastUpdate
		}
	}
	g.TouchLastUpdate(lu)
}