示例#1
0
// ShardReader returns a reader for streaming shard data.
// Returned ReadCloser must be closed by the caller.
func (c *Client) ShardReader(id uint64) (io.ReadCloser, error) {
	// Connect to remote server.
	conn, err := tcp.Dial("tcp", c.host, MuxHeader)
	if err != nil {
		return nil, err
	}

	// Send request to server.
	if err := c.writeRequest(conn, &internal.Request{ShardID: proto.Uint64(id)}); err != nil {
		return nil, fmt.Errorf("write request: %s", err)
	}

	// Read response from the server.
	resp, err := c.readResponse(conn)
	if err != nil {
		return nil, fmt.Errorf("read response: %s", err)
	}

	// If there was an error then return it and close connection.
	if resp.GetError() != "" {
		conn.Close()
		return nil, errors.New(resp.GetError())
	}

	// Returning remaining stream for caller to consume.
	return conn, nil
}
示例#2
0
// download downloads a snapshot of either the metastore or a shard from a host to a given path.
func (cmd *Command) download(req *snapshotter.Request, path string) error {
	// Create local file to write to.
	f, err := os.Create(path)
	if err != nil {
		return fmt.Errorf("open temp file: %s", err)
	}
	defer f.Close()

	// Connect to snapshotter service.
	conn, err := tcp.Dial("tcp", cmd.host, snapshotter.MuxHeader)
	if err != nil {
		return err
	}
	defer conn.Close()

	// Write the request
	if err := json.NewEncoder(conn).Encode(req); err != nil {
		return fmt.Errorf("encode snapshot request: %s", err)
	}

	// Read snapshot from the connection
	if _, err := io.Copy(f, conn); err != nil {
		return fmt.Errorf("copy backup to file: %s", err)
	}

	return nil
}
示例#3
0
// requestInfo will request the database or retention policy information from the host
func (cmd *Command) requestInfo(request *snapshotter.Request) (*snapshotter.Response, error) {
	// Connect to snapshotter service.
	conn, err := tcp.Dial("tcp", cmd.host, snapshotter.MuxHeader)
	if err != nil {
		return nil, err
	}
	defer conn.Close()

	// Write the request
	if err := json.NewEncoder(conn).Encode(request); err != nil {
		return nil, fmt.Errorf("encode snapshot request: %s", err)
	}

	// Read the response
	var r snapshotter.Response
	if err := json.NewDecoder(conn).Decode(&r); err != nil {
		return nil, err
	}

	return &r, nil
}