Additional notes for IIS fronting of xMatters using the ISAPI Redirector

This article provides additional information for xMatters Administrators who are using the ISAPI Redirector with IIS to front the xMatters web server.


Benchmarking tests indicate improved performance when fronting xMatters with IIS using isapi_redirect-1.2.26.dll and static content configuration. (Performance impact before static content configuration is negligible, and improved afterwards.)


The limitations to IIS fronting are caused by limits to active connections. These are often enforced by the Windows Operating System itself. Increasing the number of processes to six (see the following Configuration section) should resolve this issue up to a maximum of 300 concurrent users per web-head with default Windows settings.

This limitation is not caused by AlarmPoint and may be exceeded by changes to the system configuration (ISS, OS, Hardware); these changes are platform-dependent and beyond the scope of this document.


After installing the ISAPI Redirector, consult the xMatters installation and administration guide for instructions on how to front the static web content.

The only other recommended post-install change is to increase the number of processes for the DefaultAppPool from 1 to 6. This change improves stability of the system under heavy load.

To change the number of processes for the DefaultAppPool:

  1. In IIS, expand the Application Pools section.
  2. Right-click DefaultAppPool, and then click Properties.
  3. Click the Performance tab.
  4. In the Web Garden area, change the Maximum number of worker processes setting to 6.

Removing the "alarmpoint" or "xmatters" portion of the web site URL

You can create an extra redirect to set the path for xMatters, and remove the "alarmpoint" or "xmatters" portion of the web site's URL.

Note that these steps assume IIS fronting of xMatters is already configured and working in your environment.

To change the existing xMatters IIS page port from 80 to 81:

  1. In ISS, right-click the new site and select Properties.
  2. Click the Web Site tab.
  3. Change the TCP Port setting to 81 (or another free port).

To create a new web site in IIS (using the default settings):

  1. Right-click Web Sites, and then click New > Web Site.
  2. Click Next.
  3. Enter a description (e.g., APRedirect), and then click Next.
  4. Accept the default settings and click Next.
  5. In the Home field, type the URL for the home path, and then click Next. (The path for the existing xMatters page works for this step.)
  6. Ensure that the Read permission is selected, and then click Next.
  7. Click Finish.

To configure the redirect:

  1. Right-click the new site and select Properties.
  2. Click the Home Directory tab.
  3. Under The content for this resource, select A redirection to a URL.
  4. In the Redirect to field, enter the full path of the redirected xMatters entrance; e.g,http://localhost:81/alarmpoint
  5. Click the Web Site tab
  6. Change the setting for the TCP Port to 80 (or another free port).
  7. Click Apply, and then click OK.
  8. Stop and then restart the web site.

Configuring IIS Fronting for the xMatters mobile access component

The instructions below assume that you have already applied the file.

To configure IIS for use with the mobile access component:

  1. Open the file in a text editor (default location is: C:\Program Files\Apache Software Foundation\Jakarta Isapi Redirector\conf).
  2. Add the following line to the end of the file:
  1. Save and close the file.

xMatters Reference

JDN-1204 Originally created by Don Clark

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