Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm.

You can easily set the default page with below code,

Nagios server is an open source use for system monitoring, network monitoring and software application status. It gives your service alerts, information and status.

MySQL database Pluggable Storage Engine components that manage different table operation. There are two type of storage engines in MySQL Server,