When users log into ServAssure NXT, they are initially connected to one of the application UI servers on the UI Tier. The UI server then authenticates the user either using an external LDAP server or locally within Cassandra, depending on the mode of authentication. After authentication, the UI server node then makes a web service REST request to the ServAssure NXT App Engine tier. The ServAssure NXT App Engine node gathers the data required to satisfy the request. Most of the data about the network status and history is stored in Cassandra. The current view of subscriber and topology-related data is kept in Solr for fast searching.
