Install Office on ASP.NET IIS Servers: Pros / Cons?

First off, the little voi开发者_运维问答ce inside my head is screaming that this is a bad idea and it shouldn't be done, but my pragmatic side is asking "How bad could it be?"

The stark fact is most of my company's day to day "business" happens in one MS Office tool or another. Data is exported out of our custom tools as *.tab, *.csv, manipulated in Excel and imported back in with variying degrees of success.

Most of these custom tools are ASP.NET MVC web applications whose usability could be enhanced by more interoperability with Office.

I've fought the good fight for many years saying Office on a web server is a terrible idea. Lately I've been thinking that the enhanced usability outweighs the potential risks.

Am I going crazy?

You don't say what version of MS Office you are using in your workplace or what type of interoperability you are after.

If you want to generate Office documents 'on the fly' directly from the web application, then if you are using Office 2007 or 2010, the default document formats (.docx, .xlsx) are based on the Open XML SDK. This means that it is possible to generate documents dynamically without having to install MS Office on the web server.

If you are using Office 2003 or earlier, it is generally considered bad practice to install MS Office on the server - it is an unsupported configuration.

This Microsoft article outlines many of the possible issues you may face if you decide to go down this route.

Microsoft Office is not designed to work in a server which could be a highly distributed, multithreaded environment. It is a client application which by the way is mainly unmanaged code. So installing it and using it from a web server could hide potential problems: leaking handles, GDI objects, marshaling between managed/unmanaged memory, STA COM objects, etc. I would recommend you using only tools which have been designed to be used in a server environment.

You can create good office documents without installing office on the web server. Options include SpreadsheetML, components from aspose.net, and even just changing the file extension and content type on html responses to fool office itself.

If you do not want to install the full Office suite, then you can just install the Microsoft Office Primary Interop Assemblies?

http://msdn.microsoft.com/en-us/library/aa159923(office.11).aspx

I've seen this work in environments with very low loads...but as soon as the load increases the issues start to creep up. This has even be documented by Microsoft as the article pointed by Jazza clearly shows. Notice that this article is quite recent (July/2010).

The issues that I've seen are memory leaks, instances of Word/Excel not being stuck in memory, weird registry issues, and so on.

Another thing to consider is that Microsoft will not support you if you call them with issues related to Office on a server environment.

Again, if you only have a few users this might not be a problem for you initially but be prepared for scale issues.