.

go/neo/nodetab.go

@@ -437,8 +437,9 @@ func (nt *NodeTable) notify(nodeInfo NodeInfo) {
 	}
 }
 
-// Subscribe subscribes to NodeTable updates
-// it returns a channel via which updates will be delivered and unsubscribe function
+// Subscribe subscribes to NodeTable updates.
+//
+// It returns a channel via which updates will be delivered and function to unsubscribe.
 //
 // XXX locking: client for subscribe/unsubscribe	XXX ok?
 func (nt *NodeTable) Subscribe() (ch chan NodeInfo, unsubscribe func()) {
@@ -459,12 +460,13 @@ func (nt *NodeTable) Subscribe() (ch chan NodeInfo, unsubscribe func()) {
 	return ch, unsubscribe
 }
 
-// SubscribeBuffered subscribes to NodeTable updates without blocking updater
-// it returns a channel via which updates are delivered and unsubscribe function
-// the updates will be sent to destination in non-blocking way - if destination
+// SubscribeBuffered subscribes to NodeTable updates without blocking updater.
+//
+// It returns a channel via which updates are delivered and unsubscribe function.
+// The updates will be sent to destination in non-blocking way - if destination
 // channel is not ready they will be buffered.
-// it is the caller responsibility to make sure such buffering does not grow up
-// to infinity - via e.g. detecting stuck connections and unsubscribing on shutdown
+// It is the caller responsibility to make sure such buffering does not grow up
+// to infinity - via e.g. detecting stuck connections and unsubscribing on shutdown.
 //
 // XXX locking: client for subscribe/unsubscribe	XXX ok?
 func (nt *NodeTable) SubscribeBuffered() (ch chan []NodeInfo, unsubscribe func()) {

go/neo/server/cluster_test.go

@@ -36,7 +36,7 @@ import (
 	"lab.nexedi.com/kirr/neo/go/neo"
 	"lab.nexedi.com/kirr/neo/go/neo/client"
 
-	//"lab.nexedi.com/kirr/neo/go/zodb"
+	"lab.nexedi.com/kirr/neo/go/zodb"
 	"lab.nexedi.com/kirr/neo/go/zodb/storage/fs1"
 
 	"lab.nexedi.com/kirr/neo/go/xcommon/tracing"
@@ -59,11 +59,12 @@ func xwait(w interface { Wait() error }) {
 }
 
 func xfs1stor(path string) *fs1.FileStorage {
-	zstor, err := fs1.Open(context.Background(), path)
+	zstor, err := fs1.Open(bg, path)
 	exc.Raiseif(err)
 	return zstor
 }
 
+var bg = context.Background()
 
 // XXX tracer which can collect tracing events from net + TODO master/storage/etc...
 // XXX naming
@@ -212,6 +213,17 @@ func TestMasterStorage(t *testing.T) {
 		}
 	}
 
+	// shortcut for NodeInfo
+	nodei := func(typ neo.NodeType, addr string, uuid neo.NodeUUID, state neo.NodeState, idtstamp float64) neo.NodeInfo {
+		return neo.NodeInfo{
+			Type:  typ,
+			Addr:  xnaddr(addr),
+			UUID:  uuid,
+			State: state,
+			IdTimestamp: idtstamp,
+		}
+	}
+
 
 	Mhost := xnet.NetTrace(net.Host("m"), tracer)
 	Shost := xnet.NetTrace(net.Host("s"), tracer)
@@ -223,7 +235,7 @@ func TestMasterStorage(t *testing.T) {
 	Mclock := &vclock{}
 	M := NewMaster("abc1", ":1", Mhost)
 	M.monotime = Mclock.monotime
-	Mctx, Mcancel := context.WithCancel(context.Background())
+	Mctx, Mcancel := context.WithCancel(bg)
 	gwg.Gox(func() {
 		err := M.Run(Mctx)
 		fmt.Println("M err: ", err)
@@ -240,7 +252,7 @@ func TestMasterStorage(t *testing.T) {
 	// start storage
 	zstor := xfs1stor("../../zodb/storage/fs1/testdata/1.fs")
 	S := NewStorage("abc1", "m:1", ":1", Shost, zstor)
-	Sctx, Scancel := context.WithCancel(context.Background())
+	Sctx, Scancel := context.WithCancel(bg)
 	gwg.Gox(func() {
 		err := S.Run(Sctx)
 		fmt.Println("S err: ", err)
@@ -317,8 +329,8 @@ func TestMasterStorage(t *testing.T) {
 		TidDict: nil,	// map[zodb.Tid]zodb.Tid{},
 	}))
 
-	lastOid, err1 := zstor.LastOid(context.TODO())
-	lastTid, err2 := zstor.LastTid(context.TODO())
+	lastOid, err1 := zstor.LastOid(bg)
+	lastTid, err2 := zstor.LastTid(bg)
 	exc.Raiseif(xerr.Merge(err1, err2))
 	tc.Expect(conntx("m:2", "s:2", 1, &neo.LastIDs{}))
 	tc.Expect(conntx("s:2", "m:2", 1, &neo.AnswerLastIDs{
@@ -368,7 +380,15 @@ func TestMasterStorage(t *testing.T) {
 		YourUUID:	neo.UUID(neo.CLIENT, 1),
 	}))
 
-	// XXX C <- M NotifyNodeInformation C1,M1,S1
+	// C <- M NotifyNodeInformation C1,M1,S1
+	tc.Expect(conntx("m:3", "c:1", 2, &neo.NotifyNodeInformation{
+		IdTimestamp:	0,	// XXX ?
+		NodeList:	[]neo.NodeInfo{
+			nodei(neo.MASTER,  "m:1", neo.UUID(neo.MASTER, 1),  neo.RUNNING, 0.00),
+			nodei(neo.STORAGE, "s:1", neo.UUID(neo.STORAGE, 1), neo.RUNNING, 0.01),
+			nodei(neo.STORAGE, "",    neo.UUID(neo.CLIENT, 1),  neo.RUNNING, 0.02),
+		},
+	}))
 
 	// C asks M about PT
 	tc.Expect(conntx("c:1", "m:3", 3, &neo.AskPartitionTable{}))
@@ -380,9 +400,27 @@ func TestMasterStorage(t *testing.T) {
 	}))
 
 
+	// C asks M about last tid	XXX better master sends it itself on new client connected
+	wg = &xsync.WorkGroup{}
+	wg.Gox(func() {
+		cLastTid, err := C.LastTid(bg)
+		exc.Raiseif(err)
+
+		if cLastTid != lastTid {
+			exc.Raisef("C.LastTid -> %v  ; want %v", cLastTid, lastTid)
+		}
+	})
+
+	tc.Expect(conntx("c:1", "m:3", 5, &neo.LastTransaction{}))
+	tc.Expect(conntx("m:3", "c:1", 5, &neo.AnswerLastTransaction{
+		Tid: lastTid,
+	}))
+
+	// C starts loading first object
+	data, serial, err := C.Load(bg, zodb.Xid{Oid: 1, XTid: zodb.XTid{Tid: zodb.TidMax, TidBefore: true}})
+	_, _, _ = data, serial, err
 
 
-	_ = C
 
 
 
@@ -414,7 +452,7 @@ func _TestClientStorage(t *testing.T) {
 	Cnl, Snl := NodeLinkPipe()
 	wg := &xsync.WorkGroup{}
 
-	Sctx, Scancel := context.WithCancel(context.Background())
+	Sctx, Scancel := context.WithCancel(bg)
 
 	net := pipenet.New("")	// XXX here? (or a bit above?)
 	zstor := xfs1stor("../../zodb/storage/fs1/testdata/1.fs")	// XXX +readonly

go/neo/server/master.go

@@ -28,6 +28,8 @@ import (
 	"sync"
 	"time"
 
+	"golang.org/x/sync/errgroup"
+
 	"github.com/pkg/errors"
 
 	"lab.nexedi.com/kirr/neo/go/neo"
@@ -45,14 +47,15 @@ import (
 type Master struct {
 	node neo.NodeCommon
 
+	// master manages node and partition tables and broadcast their updates
+	// to all nodes in cluster
+
 	// last allocated oid & tid
 	// XXX how to start allocating oid from 0, not 1 ?
+	// TODO mu
 	lastOid zodb.Oid
 	lastTid zodb.Tid
 
-	// master manages node and partition tables and broadcast their updates
-	// to all nodes in cluster
-
 	// channels controlling main driver
 	ctlStart    chan chan error	// request to start cluster
 	ctlStop     chan chan struct{}	// request to stop  cluster
@@ -911,11 +914,19 @@ func storCtlService(ctx context.Context, stor *neo.Node) (err error) {
 func (m *Master) serveClient(ctx context.Context, cli *neo.Node) (err error) {
 	defer task.Runningf(&ctx, "%s: client service", cli.Link.RemoteAddr())(&err)
 
+	wg, ctx := errgroup.WithContext(ctx)
+
 	clink := cli.Link
 	defer xio.CloseWhenDone(ctx, clink)()
 
-	// XXX spawn M -> S notifications about cluster state
+	// M -> C notifications about cluster state
+	wg.Go(func() error {
+		//return m.notifyPeer(ctx, clink)	 // XXX -> keepPeerUpdated?
+		return nil
+	})
 
+	// M <- C requests handler
+	wg.Go(func() error {
 		for {
 			req, err := clink.Recv1()
 			if err != nil {
@@ -928,8 +939,9 @@ func (m *Master) serveClient(ctx context.Context, cli *neo.Node) (err error) {
 				return err
 			}
 		}
+	})
 
-	return nil
+	return wg.Wait()
 }
 
 // serveClient1 prepares response for 1 request from client
@@ -944,6 +956,9 @@ func (m *Master) serveClient1(ctx context.Context, req neo.Msg) (resp neo.Msg) {
 		m.node.StateMu.RUnlock()
 		return rpt
 
+	case *neo.LastTransaction:
+		// XXX lock
+		return &neo.AnswerLastTransaction{m.lastTid}
 
 	default:
 		return &neo.Error{neo.PROTOCOL_ERROR, fmt.Sprintf("unexpected message %T", req)}

go/neo/server/storage.go

@@ -52,7 +52,7 @@ type Storage struct {
 	//	data/
 	//	    1 inbox/	(commit queues)
 	//	    2 ? (data.fs)
-	//	    3. packed/
+	//	    3 packed/
 	zstor zodb.IStorage // underlying ZODB storage	XXX -> directly work with fs1 & friends
 }
 

go/zodb/zodb.go

@@ -44,6 +44,8 @@ type Xid struct {
 	Oid
 }
 
+// XXX add XidBefore() and XidSerial() as syntax convenience?
+
 const (
 	//Tid0	Tid = 0			// XXX -> simply Tid(0) ?
 	TidMax	Tid = 1<<63 - 1		// 0x7fffffffffffffff