asp.net 301 redirect for big data

Question

I have changed my website database, and i have more than 10000 url has been changed, and i need to do 301 redirect, what is best way to handle that big amount of data as 301 redirect ?

i cannt do it by using web.config, the file will became very big, and it will take much effort

<httpRedirect enabled="true" exactDestination="true" httpResponseStatus="Permanent">
     <add wildcard="/MyOldAspFile.aspx" destination="/MyNewFile.aspx" />
     <add wildcard="/MyOldHtmlFile.html" destination="/MyNewFile.aspx" />
</httpRedirect>

so, what is the best way to handle that case ?

Answer 1

I want to recommend to use rewrite maps for that purpose. And store rewrite map in another file. In your web.config it will be:

<rewrite>
  <rewriteMaps configSource="rewriteMaps.config"/>
  <rules configSource="rewriteRules.config"/>
</rewrite>

In your rewriteRules.config;

<rules>
   <rule name="Rule for Redirects">
      <match url=".*" />
      <conditions>
         <add input="{Redirects:{REQUEST_URI}}" pattern="(.+)" />
      </conditions>
      <action type="Redirect" url="{C:1}" appendQueryString="false" />
   </rule>
</rules>

In your rewriteMaps.config:

<rewriteMaps>
    <rewriteMap name="Redirects">
        <add key="/old1" value="/new1" />
        <add key="/old2" value="/new2" />
     </rewriteMap>
</rewriteMaps>

And URL Rewrite Module should be installed in your IIS

You can fill rewriteMaps programmatically, if you have DB with old urls. Sample of simple logic is here:

var urls = new Dictionary<string, string>();
urls.Add("/old", "/new");

var lines = new List<string>();

lines.Add("<rewriteMaps>");
lines.Add("<rewriteMap name=\"Redirects\">");

foreach (var url in urls)
{
    lines.Add(string.Format("<add key=\"{0}\" value=\"{1}\" />", url.Key, url.Value));
}

lines.Add("</rewriteMap>");
lines.Add("</rewriteMaps>");

System.IO.File.WriteAllLines(@"rewriteMaps.config", lines);