@Override
  public ByteBuffer processCommand(RequestReader request, Protocol protocol, Cache cache) {
    String version = GemFireMemcachedServer.version;
    if (protocol == Protocol.ASCII) {
      return asciiCharset.encode("VERSION " + version + "\r\n");
    }
    ByteBuffer response = request.getResponse(HEADER_LENGTH + version.length());
    response.putInt(TOTAL_BODY_LENGTH_INDEX, version.length());
    response.position(HEADER_LENGTH);
    response.put(asciiCharset.encode(version));
    response.rewind();
    request.getRequest().position(HEADER_LENGTH);
    return response;
  }
Sends current version of gemcached server to the client
geode-memcached/src/main/java/org/apache/geode/internal/memcached/commands/VersionCommand.java