在LoadRunner里何时该用 .NET  Vuser协议?

URL:

http://www.performancecompetence.com/wordpress/2009/11/21/when-should-we-use-net-vuser-protocol-in-loadrunner/

译者：kaixin322        原作者：Chaitanya M Bhatt

通常，当程序员使用.NET/VB/Java Applet来进行开发的时候，大多数情况下，应用程序并不会使用开放的标准协议，比如HTTP协议。因而loadrunner协议捕捉任何通过该应用层的消息都将失败。

开发者使用.NET/VB/Java Applet开发一个应用程序的时候，他们通常会使用自定义的消息格式。

这也就意味着，当客户端和服务器对话时，没有任何一个Loadrunner协议可以识别这些消息，因为它没有被预定义过。

解决方案：既然录制-回放选项是并存的，你可以应用反编译，使你应用程序的这些DLL更加具有可读性。而且，你还可以考虑从开发人员那得到帮助，利用应用程序本身的源程序，在.NET Vu 或 VB Vu里创建工作流脚本。如果开发者基于安全考虑，故意笼罩/混淆了代码，这项工作将是非常具有挑战性的。因而，我强烈建议，在脚本准备阶段从开发人员那边获得帮助。

应用必备工具：http://www.remotesoft.com/salamander/

糟糕的是,如果都不行，为了节省时间你可以选择以下途径：当且仅当你的负载场景是轻量级的，有10-50个虚拟用户，你可以应用RDP（类似录制）协议，录制键盘输入和鼠标点击。如果你的目标是更高的虚拟用户，就可能需要更高甚至负载生成器硬件。

你也可以尝试用Winsock协议。如果你很幸运，那在通过Sockets套接字的时候，你的应用程序缓冲区就会比较小。这时，winsock脚本会更具有可读性，而且相对的比上面提到的方法更加具有可行性。

（同样，谨代表个人观点）

##############   原文  ##############

When should we use .NET Vuser protocol in LoadRunner?

Basically when programmers goes for .NET/VB/Java applet driven
development – most oftenly the application would not use open
standards like HTTP and hence loadrunner protocols would fail to
capture any of the messages sent through the application layer.

Developers would generally use custom messaging formats when they
develop an application using .NET/VB/Java applets, so this means when
the client and server are speaking with each other none of the
loadrunner protocols can identify the message because it hasn’t been
predefined.

Solution: Since contemporary record-replay option is ruled you can use
decompilers to make those DLL’s of your application more readable and
you should also consider getting help from the developers to build
workflow scripts using the source code of the application itself
in .NET Vu or VB Vu. This task could be challenging if the developers
have shrouded/obfuscated the code intentionally for security purpose,
hence i strongly suggest you get developer’s support during script
preperation
This tool can come in handly if your application :http://www.remotesoft.com/salamander/

Worst case if nothing works, for the benifit of time you may choose
the following approach only if your workload scenario is light weight
with 10-50 virtual users, you may use RDP(analog recording) protocol
which records inputs of Keyboards and Mouse Clicks. You may need
higher end loadgenerator hardware if your targetting a higher range of
virtual user.

You can also try Winsock protocol. You may be lucky if your
application buffer passing through the sockets is small in size and
probably in which case your winsock script might be more readable and
may relatively be more feasible than any of the above mentioned methods
(again…it is subjective).