p2p/discover: fix #838, evacuate self entries from the node db

This commit is contained in:
Péter Szilágyi 2015-05-21 19:41:46 +03:00
parent af24c271c7
commit cbd3ae6906
3 changed files with 99 additions and 25 deletions

View File

@ -33,6 +33,8 @@ type nodeDB struct {
lvl *leveldb.DB // Interface to the database itself
seeder iterator.Iterator // Iterator for fetching possible seed nodes
self NodeID // Own node id to prevent adding it into the database
runner sync.Once // Ensures we can start at most one expirer
quit chan struct{} // Channel to signal the expiring thread to stop
}
@ -50,29 +52,30 @@ var (
// newNodeDB creates a new node database for storing and retrieving infos about
// known peers in the network. If no path is given, an in-memory, temporary
// database is constructed.
func newNodeDB(path string, version int) (*nodeDB, error) {
func newNodeDB(path string, version int, self NodeID) (*nodeDB, error) {
if path == "" {
return newMemoryNodeDB()
return newMemoryNodeDB(self)
}
return newPersistentNodeDB(path, version)
return newPersistentNodeDB(path, version, self)
}
// newMemoryNodeDB creates a new in-memory node database without a persistent
// backend.
func newMemoryNodeDB() (*nodeDB, error) {
func newMemoryNodeDB(self NodeID) (*nodeDB, error) {
db, err := leveldb.Open(storage.NewMemStorage(), nil)
if err != nil {
return nil, err
}
return &nodeDB{
lvl: db,
self: self,
quit: make(chan struct{}),
}, nil
}
// newPersistentNodeDB creates/opens a leveldb backed persistent node database,
// also flushing its contents in case of a version mismatch.
func newPersistentNodeDB(path string, version int) (*nodeDB, error) {
func newPersistentNodeDB(path string, version int, self NodeID) (*nodeDB, error) {
opts := &opt.Options{OpenFilesCacheCapacity: 5}
db, err := leveldb.OpenFile(path, opts)
if _, iscorrupted := err.(*errors.ErrCorrupted); iscorrupted {
@ -102,11 +105,12 @@ func newPersistentNodeDB(path string, version int) (*nodeDB, error) {
if err = os.RemoveAll(path); err != nil {
return nil, err
}
return newPersistentNodeDB(path, version)
return newPersistentNodeDB(path, version, self)
}
}
return &nodeDB{
lvl: db,
self: self,
quit: make(chan struct{}),
}, nil
}
@ -182,6 +186,17 @@ func (db *nodeDB) updateNode(node *Node) error {
return db.lvl.Put(makeKey(node.ID, nodeDBDiscoverRoot), blob, nil)
}
// deleteNode deletes all information/keys associated with a node.
func (db *nodeDB) deleteNode(id NodeID) error {
deleter := db.lvl.NewIterator(util.BytesPrefix(makeKey(id, "")), nil)
for deleter.Next() {
if err := db.lvl.Delete(deleter.Key(), nil); err != nil {
return err
}
}
return nil
}
// ensureExpirer is a small helper method ensuring that the data expiration
// mechanism is running. If the expiration goroutine is already running, this
// method simply returns.
@ -227,17 +242,14 @@ func (db *nodeDB) expireNodes() error {
if field != nodeDBDiscoverRoot {
continue
}
// Skip the node if not expired yet
if seen := db.lastPong(id); seen.After(threshold) {
continue
}
// Otherwise delete all associated information
deleter := db.lvl.NewIterator(util.BytesPrefix(makeKey(id, "")), nil)
for deleter.Next() {
if err := db.lvl.Delete(deleter.Key(), nil); err != nil {
return err
// Skip the node if not expired yet (and not self)
if bytes.Compare(id[:], db.self[:]) != 0 {
if seen := db.lastPong(id); seen.After(threshold) {
continue
}
}
// Otherwise delete all associated information
db.deleteNode(id)
}
return nil
}
@ -286,6 +298,11 @@ func (db *nodeDB) querySeeds(n int) []*Node {
if field != nodeDBDiscoverRoot {
continue
}
// Dump it if its a self reference
if bytes.Compare(id[:], db.self[:]) == 0 {
db.deleteNode(id)
continue
}
// Load it as a potential seed
if node := db.node(id); node != nil {
nodes = append(nodes, node)

View File

@ -63,7 +63,7 @@ var nodeDBInt64Tests = []struct {
}
func TestNodeDBInt64(t *testing.T) {
db, _ := newNodeDB("", Version)
db, _ := newNodeDB("", Version, NodeID{})
defer db.close()
tests := nodeDBInt64Tests
@ -94,7 +94,7 @@ func TestNodeDBFetchStore(t *testing.T) {
)
inst := time.Now()
db, _ := newNodeDB("", Version)
db, _ := newNodeDB("", Version, NodeID{})
defer db.close()
// Check fetch/store operations on a node ping object
@ -165,7 +165,7 @@ var nodeDBSeedQueryNodes = []struct {
}
func TestNodeDBSeedQuery(t *testing.T) {
db, _ := newNodeDB("", Version)
db, _ := newNodeDB("", Version, NodeID{})
defer db.close()
// Insert a batch of nodes for querying
@ -205,7 +205,7 @@ func TestNodeDBSeedQuery(t *testing.T) {
}
func TestNodeDBSeedQueryContinuation(t *testing.T) {
db, _ := newNodeDB("", Version)
db, _ := newNodeDB("", Version, NodeID{})
defer db.close()
// Insert a batch of nodes for querying
@ -230,6 +230,32 @@ func TestNodeDBSeedQueryContinuation(t *testing.T) {
}
}
func TestNodeDBSelfSeedQuery(t *testing.T) {
// Assign a node as self to verify evacuation
self := nodeDBSeedQueryNodes[0].node.ID
db, _ := newNodeDB("", Version, self)
defer db.close()
// Insert a batch of nodes for querying
for i, seed := range nodeDBSeedQueryNodes {
if err := db.updateNode(seed.node); err != nil {
t.Fatalf("node %d: failed to insert: %v", i, err)
}
}
// Retrieve the entire batch and check that self was evacuated
seeds := db.querySeeds(2 * len(nodeDBSeedQueryNodes))
if len(seeds) != len(nodeDBSeedQueryNodes)-1 {
t.Errorf("seed count mismatch: have %v, want %v", len(seeds), len(nodeDBSeedQueryNodes)-1)
}
have := make(map[NodeID]struct{})
for _, seed := range seeds {
have[seed.ID] = struct{}{}
}
if _, ok := have[self]; ok {
t.Errorf("self not evacuated")
}
}
func TestNodeDBPersistency(t *testing.T) {
root, err := ioutil.TempDir("", "nodedb-")
if err != nil {
@ -243,7 +269,7 @@ func TestNodeDBPersistency(t *testing.T) {
)
// Create a persistent database and store some values
db, err := newNodeDB(filepath.Join(root, "database"), Version)
db, err := newNodeDB(filepath.Join(root, "database"), Version, NodeID{})
if err != nil {
t.Fatalf("failed to create persistent database: %v", err)
}
@ -253,7 +279,7 @@ func TestNodeDBPersistency(t *testing.T) {
db.close()
// Reopen the database and check the value
db, err = newNodeDB(filepath.Join(root, "database"), Version)
db, err = newNodeDB(filepath.Join(root, "database"), Version, NodeID{})
if err != nil {
t.Fatalf("failed to open persistent database: %v", err)
}
@ -263,7 +289,7 @@ func TestNodeDBPersistency(t *testing.T) {
db.close()
// Change the database version and check flush
db, err = newNodeDB(filepath.Join(root, "database"), Version+1)
db, err = newNodeDB(filepath.Join(root, "database"), Version+1, NodeID{})
if err != nil {
t.Fatalf("failed to open persistent database: %v", err)
}
@ -300,7 +326,7 @@ var nodeDBExpirationNodes = []struct {
}
func TestNodeDBExpiration(t *testing.T) {
db, _ := newNodeDB("", Version)
db, _ := newNodeDB("", Version, NodeID{})
defer db.close()
// Add all the test nodes and set their last pong time
@ -323,3 +349,34 @@ func TestNodeDBExpiration(t *testing.T) {
}
}
}
func TestNodeDBSelfExpiration(t *testing.T) {
// Find a node in the tests that shouldn't expire, and assign it as self
var self NodeID
for _, node := range nodeDBExpirationNodes {
if !node.exp {
self = node.node.ID
break
}
}
db, _ := newNodeDB("", Version, self)
defer db.close()
// Add all the test nodes and set their last pong time
for i, seed := range nodeDBExpirationNodes {
if err := db.updateNode(seed.node); err != nil {
t.Fatalf("node %d: failed to insert: %v", i, err)
}
if err := db.updateLastPong(seed.node.ID, seed.pong); err != nil {
t.Fatalf("node %d: failed to update pong: %v", i, err)
}
}
// Expire the nodes and make sure self has been evacuated too
if err := db.expireNodes(); err != nil {
t.Fatalf("failed to expire nodes: %v", err)
}
node := db.node(self)
if node != nil {
t.Errorf("self not evacuated")
}
}

View File

@ -68,10 +68,10 @@ type bucket struct {
func newTable(t transport, ourID NodeID, ourAddr *net.UDPAddr, nodeDBPath string) *Table {
// If no node database was given, use an in-memory one
db, err := newNodeDB(nodeDBPath, Version)
db, err := newNodeDB(nodeDBPath, Version, ourID)
if err != nil {
glog.V(logger.Warn).Infoln("Failed to open node database:", err)
db, _ = newNodeDB("", Version)
db, _ = newNodeDB("", Version, ourID)
}
tab := &Table{
net: t,