// handleFetchData handles a request for the current nodes meta data
func (r *rpc) handleFetchData(req *internal.FetchDataRequest) (*internal.FetchDataResponse, error) {
var (
b []byte
data *Data
err error
)
for {
data = r.store.cachedData()
if data.Index != req.GetIndex() {
b, err = data.MarshalBinary()
if err != nil {
return nil, err
}
break
}
if !req.GetBlocking() {
break
}
if err := r.store.WaitForDataChanged(); err != nil {
return nil, err
}
}
return &internal.FetchDataResponse{
Header: &internal.ResponseHeader{
OK: proto.Bool(true),
},
Index: proto.Uint64(data.Index),
Term: proto.Uint64(data.Term),
Data: b}, nil
}
// marshal serializes to a protobuf representation.
func (si ShardInfo) marshal() *internal.ShardInfo {
pb := &internal.ShardInfo{
ID: proto.Uint64(si.ID),
}
pb.OwnerIDs = make([]uint64, len(si.OwnerIDs))
copy(pb.OwnerIDs, si.OwnerIDs)
return pb
}
// fetchMetaData returns the latest copy of the meta store data from the current
// leader.
func (r *rpc) fetchMetaData(blocking bool) (*Data, error) {
assert(r.store != nil, "store is nil")
// Retrieve the current known leader.
leader := r.store.Leader()
if leader == "" {
return nil, errors.New("no leader")
}
var index, term uint64
data := r.store.cachedData()
if data != nil {
index = data.Index
term = data.Index
}
resp, err := r.call(leader, &internal.FetchDataRequest{
Index: proto.Uint64(index),
Term: proto.Uint64(term),
Blocking: proto.Bool(blocking),
})
if err != nil {
return nil, err
}
switch t := resp.(type) {
case *internal.FetchDataResponse:
// If data is nil, then the term and index we sent matches the leader
if t.GetData() == nil {
return nil, nil
}
ms := &Data{}
if err := ms.UnmarshalBinary(t.GetData()); err != nil {
return nil, fmt.Errorf("rpc unmarshal metadata: %v", err)
}
return ms, nil
case *internal.ErrorResponse:
return nil, fmt.Errorf("rpc failed: %s", t.GetHeader().GetError())
default:
return nil, fmt.Errorf("rpc failed: unknown response type: %v", t.String())
}
}
// marshal serializes to a protobuf representation.
func (data *Data) marshal() *internal.Data {
pb := &internal.Data{
Term: proto.Uint64(data.Term),
Index: proto.Uint64(data.Index),
ClusterID: proto.Uint64(data.ClusterID),
MaxNodeID: proto.Uint64(data.MaxNodeID),
MaxShardGroupID: proto.Uint64(data.MaxShardGroupID),
MaxShardID: proto.Uint64(data.MaxShardID),
}
pb.Nodes = make([]*internal.NodeInfo, len(data.Nodes))
for i := range data.Nodes {
pb.Nodes[i] = data.Nodes[i].marshal()
}
pb.Databases = make([]*internal.DatabaseInfo, len(data.Databases))
for i := range data.Databases {
pb.Databases[i] = data.Databases[i].marshal()
}
pb.Users = make([]*internal.UserInfo, len(data.Users))
for i := range data.Users {
pb.Users[i] = data.Users[i].marshal()
}
return pb
}
// marshal serializes to a protobuf representation.
func (sgi *ShardGroupInfo) marshal() *internal.ShardGroupInfo {
pb := &internal.ShardGroupInfo{
ID: proto.Uint64(sgi.ID),
StartTime: proto.Int64(MarshalTime(sgi.StartTime)),
EndTime: proto.Int64(MarshalTime(sgi.EndTime)),
DeletedAt: proto.Int64(MarshalTime(sgi.DeletedAt)),
}
pb.Shards = make([]*internal.ShardInfo, len(sgi.Shards))
for i := range sgi.Shards {
pb.Shards[i] = sgi.Shards[i].marshal()
}
return pb
}
// handleJoinRequest handles a request to join the cluster
func (r *rpc) handleJoinRequest(req *internal.JoinRequest) (*internal.JoinResponse, error) {
r.traceCluster("join request from: %v", *req.Addr)
node, err := func() (*NodeInfo, error) {
// attempt to create the node
node, err := r.store.CreateNode(*req.Addr)
// if it exists, return the existing node
if err == ErrNodeExists {
return r.store.NodeByHost(*req.Addr)
} else if err != nil {
return nil, fmt.Errorf("create node: %v", err)
}
// FIXME: jwilder: adding raft nodes is tricky since going
// from 1 node (leader) to two kills the cluster because
// quorum is lost after adding the second node. For now,
// can only add non-raft enabled nodes
// If we have less than 3 nodes, add them as raft peers
// if len(r.store.Peers()) < MaxRaftNodes {
// if err = r.store.AddPeer(*req.Addr); err != nil {
// return node, fmt.Errorf("add peer: %v", err)
// }
// }
return node, err
}()
nodeID := uint64(0)
if node != nil {
nodeID = node.ID
}
if err != nil {
return nil, err
}
return &internal.JoinResponse{
Header: &internal.ResponseHeader{
OK: proto.Bool(true),
},
//EnableRaft: proto.Bool(contains(r.store.Peers(), *req.Addr)),
EnableRaft: proto.Bool(false),
RaftNodes: r.store.Peers(),
NodeID: proto.Uint64(nodeID),
}, err
}
// marshal serializes to a protobuf representation.
func (ni NodeInfo) marshal() *internal.NodeInfo {
pb := &internal.NodeInfo{}
pb.ID = proto.Uint64(ni.ID)
pb.Host = proto.String(ni.Host)
return pb
}