Menu
Azure App Service AlwaysOn works perfectly once there is no custom domain set for the web application. Once custom domain is added along with URL rewrite rule to redirect all incoming request to it, application starts to response slowly after some time of inactivity. Logs show that AlwaysOn still pings azure domain and gets HTTP 301 response ans is not trying to request new URL.
Log without custom domain:
2017-06-20 17:17:02 ZZTESTSITE GET / X-ARR-LOG-ID=743965b6-d3e2-42b9-9353-7772f9fbc898 80 - ::1 AlwaysOn ARRAffinity=b5289afa9cd711b67c1fe9137a6e3ff232f80bd3fa1bd96e9fc89992472b4e57 - zztestsite.azurewebsites.net 200 0 0 11433 652 15
Log with custom domain
2017-06-21 13:28:52 ZZTESTSITE GET / X-ARR-LOG-ID=ffcd5992-5019-48ca-a386-76443a8c7226 80 - ::1 AlwaysOn ARRAffinity=b5289afa9cd711b67c1fe9137a6e3ff232f80bd3fa1bd96e9fc89992472b4e57 - zztestsite.azurewebsites.net 301 0 0 553 652 46
URL Rewrite rule:
<rule name="Redirect requests from default azure websites domain to custom one" stopProcessing="true">
<match url="(.*)" />
<conditions logicalGrouping="MatchAny">
<add input="{HTTP_HOST}" pattern="^zztestsite\.azurewebsites\.net$" />
</conditions>
<action type="Redirect" url="http://mycustomdomain.com" redirectType="Permanent" appendQueryString="false"/>
</rule>
Additionally once SSL in enabled and another rule is added to redirect all requests to HTTPS, same issue will arise.
How can I tackle this problem? I found two possible directions:
Please advise.
679
Under Azure App Home page for your app., scroll down on left to "Developer tools" - Select Clone app. Add a new URL and update area etc. You can then go and add your custom domain after, etc.
05 On the General settings panel, under Platform settings, select On next to Always on configuration setting to enable the Always On feature for the selected Azure App Services web application. Click Save to apply the changes.
When you create a new website by using Web Apps in Azure, a default sitename.azurewebsites.net domain is assigned to your site. If you add a custom host name to your site and don't want users to be able to access your default *. azurewebsites.net domain, you can redirect the default URL.
Try adding this line to your conditions:
<conditions>
<add input="{HTTP_HOST}" pattern="^zztestsite\.azurewebsites\.net$" />
<add input="{WARMUP_REQUEST}" pattern="1" negate="true" />
</conditions>
This tells is not to redirect for the Always On pings. Also note that I removed the MatchAny, as you really want MatchAll here (irrelevant when you only had one).
See here for a more complete example. It's for redirecting http to https, but the core idea is the same with respect to Always On requests. That example is an xdt transform, so it looks a bit different from 'straight' config. In fact you might consider using such xdt instead of polluting your web.config.
153
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
