What is the reason to have a minimum default value for the “executionTimeout” attribute?

Question

If SharePoint Upload time limit can be increased as we wish, why the default is not set to be Max? What is the reason to have a minimum default value for the attribute "executionTimeout"?

<location path="upload.aspx">
    <system.web>
      <httpRuntime executionTimeout="XXX" maxRequestLength="2097151" />
    </system.web>
</location>

Is it recommended to increase as we wish?

Answer 1

According to MSDN property maxRequestLength

Specifies the limit for the input stream buffering threshold, in KB. This limit can be used to prevent denial of service attacks that are caused, for example, by users posting large files to the server.

By default for SharePoint 2010 it value is set to 50 MB:

<httpRuntime maxRequestLength="51200" />

According to SharePoint Server 2010 capacity management: Software boundaries and limits which describes software boundaries and limits of Microsoft SharePoint Server 2010:

Upload file size could be increased up to 2047 MB, however a large volume of very large files can affect farm performance

Execution Timeout

According to the MSDN the executionTimeout is a TimeSpan attribute that

specifies the maximum number of seconds that a request is allowed to execute before being automatically shut down by ASP.NET

In SharePoint 2010 by default it value is set to 1 hour.

It value should be increased in case if "Request Timed Out" error occurs

[HttpException (0x80004005): Request timed out.]

,otherwise there is no need to modify it value.