RK for IIS Overview

Recovery

RK for IIS protects sites as IIS resource hierarchies to prevent the following types of failures:

• System failure or server outage
• Network interface card (NIC) failure
• Communication failure (the site is running but not responding)
• Startup failure (the site enters a halted state during startup)

RK for IIS supports two recovery procedures:

• System or NIC failure – The IIS resource hierarchy fails over to a standby node.
• Communication or startup failure – If local recovery is enabled, RK for IIS first stops and restarts the affected site to determine whether the issue can be resolved locally. If the restart fails, the IIS resource hierarchy is failed over to a standby node.

Monitoring

RK for IIS verifies connectivity to the protected sites during IIS resource startup and while performing deep checks to detect communication failures.

If no URL is specified when creating an IIS resource, connectivity is verified using the IP address and port number assigned to the corresponding site. If the connection and authentication succeed, communication is considered successful regardless of the HTTP response code.

If a URL is specified during IIS resource creation, connectivity is verified using that URL. In this case, a failure is determined not only by connection or authentication errors, but also by an abnormal response code returned despite a successful connection and authentication. When such a failure is detected, RK for IIS initiates local recovery or fails over the IIS resource hierarchy.

For secure websites that use encrypted communication, issues with the server certificate are not treated as failures.

Resource Configuration

RK for IIS manages dependencies between IIS resources, IP address resources, and volume resources. To establish these dependencies, the IP address and Volume resources used by the site must be created first. When the IIS resource is subsequently created, RK for IIS reads the configuration of the protected site, identifies the corresponding IP address resources and volume resources, and automatically creates the required dependencies.

The IP address resource protects the IP address assigned to the website. The volume resource protects the disk volume containing the website’s physical path.

Below is an example of an IIS resource hierarchy as displayed in LifeKeeper Windows Management Console (LKWMC). The IIS resource protecting the “IIS-Web” website has dependencies on both the “ip-Web” IP address resource and the “Vol.D” volume resource.