[YARN-9076] ContainerShellWebSocket Render Process Output

• Type: Improvement
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.3.0
• Component/s: webapp
• Flags: Patch
• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 01/Dec/18 00:01
• Updated: 01/Mar/19 15:02

Description

ContainerShellWebSocket.java

        // Render process output
        int no = pair.in.available();
        pair.in.read(buffer, 0, Math.min(no, buffer.length));
        String formatted = new String(buffer, Charset.forName("UTF-8"))
            .replaceAll("\n", "\r\n");
        session.getRemote().sendString(formatted);
      }

This code strikes me as a bit odd. First of it, it is using available which is known as a being unreliable and inaccurate (i.e., for sockets) . Second, it will only read a max of 4000 characters and that's it. Anything else is truncated.

Change this code to read the entire data stream.