Update raft to fix atomics alingment on 32bit

Related to #2963

Also pulls in some state file syncing improvements

vendor/github.com/hashicorp/raft/file_snapshot.go

@@ -37,10 +37,11 @@ type snapMetaSlice []*fileSnapshotMeta
 
 // FileSnapshotSink implements SnapshotSink with a file.
 type FileSnapshotSink struct {
-	store  *FileSnapshotStore
-	logger *log.Logger
-	dir    string
-	meta   fileSnapshotMeta
+	store     *FileSnapshotStore
+	logger    *log.Logger
+	dir       string
+	parentDir string
+	meta      fileSnapshotMeta
 
 	stateFile *os.File
 	stateHash hash.Hash64
@@ -158,9 +159,10 @@ func (f *FileSnapshotStore) Create(version SnapshotVersion, index, term uint64,
 
 	// Create the sink
 	sink := &FileSnapshotSink{
-		store:  f,
-		logger: f.logger,
-		dir:    path,
+		store:     f,
+		logger:    f.logger,
+		dir:       path,
+		parentDir: f.path,
 		meta: fileSnapshotMeta{
 			SnapshotMeta: SnapshotMeta{
 				Version:            version,
@@ -404,6 +406,19 @@ func (s *FileSnapshotSink) Close() error {
 		return err
 	}
 
+	// fsync the parent directory, to sync directory edits to disk
+	parentFH, err := os.Open(s.parentDir)
+	defer parentFH.Close()
+	if err != nil {
+		s.logger.Printf("[ERR] snapshot: Failed to open snapshot parent directory %v, error: %v", s.parentDir, err)
+		return err
+	}
+
+	if err = parentFH.Sync(); err != nil {
+		s.logger.Printf("[ERR] snapshot: Failed syncing parent directory %v, error: %v", s.parentDir, err)
+		return err
+	}
+
 	// Reap any old snapshots
 	if err := s.store.ReapSnapshots(); err != nil {
 		return err
@@ -437,6 +452,11 @@ func (s *FileSnapshotSink) finalize() error {
 		return err
 	}
 
+	// Sync to force fsync to disk
+	if err := s.stateFile.Sync(); err != nil {
+		return err
+	}
+
 	// Get the file size
 	stat, statErr := s.stateFile.Stat()
 
@@ -468,13 +488,21 @@ func (s *FileSnapshotSink) writeMeta() error {
 
 	// Buffer the file IO
 	buffered := bufio.NewWriter(fh)
-	defer buffered.Flush()
 
 	// Write out as JSON
 	enc := json.NewEncoder(buffered)
 	if err := enc.Encode(&s.meta); err != nil {
 		return err
 	}
+
+	if err = buffered.Flush(); err != nil {
+		return err
+	}
+
+	if err = fh.Sync(); err != nil {
+		return err
+	}
+
 	return nil
 }
 

vendor/github.com/hashicorp/raft/observer.go

@@ -24,6 +24,12 @@ type FilterFn func(o *Observation) bool
 
 // Observer describes what to do with a given observation.
 type Observer struct {
+	// numObserved and numDropped are performance counters for this observer.
+	// 64 bit types must be 64 bit aligned to use with atomic operations on
+	// 32 bit platforms, so keep them at the top of the struct.
+	numObserved uint64
+	numDropped  uint64
+
 	// channel receives observations.
 	channel chan Observation
 
@@ -37,10 +43,6 @@ type Observer struct {
 
 	// id is the ID of this observer in the Raft map.
 	id uint64
-
-	// numObserved and numDropped are performance counters for this observer.
-	numObserved uint64
-	numDropped  uint64
 }
 
 // NewObserver creates a new observer that can be registered

vendor/github.com/hashicorp/raft/state.go

@@ -42,6 +42,10 @@ func (s RaftState) String() string {
 // and provides an interface to set/get the variables in a
 // thread safe manner.
 type raftState struct {
+	// currentTerm commitIndex, lastApplied,  must be kept at the top of
+	// the struct so they're 64 bit aligned which is a requirement for
+	// atomic ops on 32 bit platforms.
+
 	// The current term, cache of StableStore
 	currentTerm uint64
 

vendor/vendor.json

@@ -869,10 +869,10 @@
 			"revision": "a14192a58a694c123d8fe5481d4a4727d6ae82f3"
 		},
 		{
-			"checksumSHA1": "OCPP4JxnuSSmweEL9khCd6OdIts=",
+			"checksumSHA1": "ecpaHOImbL/NaivWrUDUUe5461E=",
 			"path": "github.com/hashicorp/raft",
-			"revision": "e45173826775c4b782961c7b5758ba484b91464b",
-			"revisionTime": "2017-07-10T17:20:01Z"
+			"revision": "3a6f3bdfe4fc69e300c6d122b1a92051af6f0b95",
+			"revisionTime": "2017-08-07T22:22:24Z"
 		},
 		{
 			"checksumSHA1": "QAxukkv54/iIvLfsUP6IK4R0m/A=",