Apache
Apache Web servers can be protected in many
ways. To save costs of redundant hardware, an active active environment can be
used. Where there are multiple Apache servers, these can be protected in an N+1
environment, here, multiple servers (up to 32) can failover to one server.
IIS
IIS can be
protected in different ways, N+1 and active active environments are some of the
ways in which hardware and software costs can be reduced. For example, an IIS
and a SQL Server can be used as a standby for each other.