nsqd: remove ID from metadata filename

nsqd/nsqd.go

@@ -271,13 +271,21 @@ func (n *NSQD) LoadMetadata() {
 	atomic.StoreInt32(&n.isLoading, 1)
 	defer atomic.StoreInt32(&n.isLoading, 0)
 
-	fn := fmt.Sprintf(path.Join(n.getOpts().DataPath, "nsqd.%d.dat"), n.getOpts().ID)
+	fn := path.Join(n.getOpts().DataPath, "nsqd.dat")
+	oldFn := fmt.Sprintf(path.Join(n.getOpts().DataPath, "nsqd.%d.dat"), n.getOpts().ID)
+
 	data, err := ioutil.ReadFile(fn)
 	if err != nil {
 		if !os.IsNotExist(err) {
 			n.logf("ERROR: failed to read channel metadata from %s - %s", fn, err)
 		}
-		return
+		data, err = ioutil.ReadFile(oldFn)
+		if err != nil {
+			if !os.IsNotExist(err) {
+				n.logf("ERROR: failed to read channel metadata from %s - %s", fn, err)
+			}
+			return
+		}
 	}
 
 	var m meta
@@ -313,7 +321,8 @@ func (n *NSQD) LoadMetadata() {
 func (n *NSQD) PersistMetadata() error {
 	// persist metadata about what topics/channels we have
 	// so that upon restart we can get back to the same state
-	fileName := fmt.Sprintf(path.Join(n.getOpts().DataPath, "nsqd.%d.dat"), n.getOpts().ID)
+	fileName := path.Join(n.getOpts().DataPath, "nsqd.dat")
+	oldFileName := fmt.Sprintf(path.Join(n.getOpts().DataPath, "nsqd.%d.dat"), n.getOpts().ID)
 	n.logf("NSQ: persisting topic/channel metadata to %s", fileName)
 
 	js := make(map[string]interface{})
@@ -370,6 +379,11 @@ func (n *NSQD) PersistMetadata() error {
 		return err
 	}
 
+	err = os.Remove(oldFileName)
+	if !os.IsNotExist(err) {
+		n.logf("NSQ: WARNING: failed to delete old metadata file %s: %s", oldFileName, err)
+	}
+
 	return nil
 }