There are two main server groups in the MicroStrategy architecture. The core of the MicroStrategy platform is an application server called Intelligence Server. There are also two servers that will publish the information to the appropriate delivery method. These servers are the Web and Mobile servers. In the following sections we will learn about them.

The following diagram shows where the Intelligence Server resides within the platform's architecture:

The application server responsible for orchestrating every other component in the MicroStrategy platform is the Intelligence Server, also called I-Server. It is also the component that handles communication with the data sources (such as data warehouse or nonrelational databases) and the metadata database. There are three main I-Server engines, shown as follows:

• SQL Engine
  The SQL Engine is responsible for creating the optimized SQL for the database. Once the SQL is generated, the I-Server SQL Engine will pass it to the Query Engine for execution. The SQL Engine also controls the other two engines.

• Query Engine
  The Query Engine is responsible for sending the SQL towards the database. The I-Server Query Engine will connect to the database via ODBC (Open Database Connectivity) and execute the query. Once the SQL is executed, it will receive it and send it to the Analytical Engine for cross tabbing or additional nonSQL functions.

• Analytical Engine
  The Analytical Engine is responsible for nonSQL actions such as in-memory manipulations and cross tabbing. Some typical examples of calculations not resolved by the SQL are functions that are not commonly supported by the database like rankings, subtotals, and other OLAP functions. This engine is also responsible for laying out the data in a cross-tab format. Finally, the Analytical Engine is in charge of any in-memory manipulation of the report (this is after the dataset is returned from the database) such as pivoting, Page-by, sorting, and conditional formatting.

In addition, there are three I-Server components that allow scalability, optimization, and distribution of the information:

• OLAP Services
  MicroStrategy OLAP Services enable MOLAP capabilities with the creation and manipulation of in-memory datasets called Intelligent Cubes. (For more information refer to Chapter 4, Advanced Reporting - Interacting with and Improving Your Reports).

• Report Services
  MicroStrategy Report Services allow flexible reporting layouts to create dashboards and scorecards. (For more information refer to Chapter 5, Dashboarding - Creating Visual Reporting).

• Distribution Services
  MicroStrategy Distribution Services facilitate the delivery of reports and dashboards supporting multiple formats, schedules, and transmitters such as email, printers, and file servers.

The following diagram shows where Web and Mobile servers reside within the platform's architecture:

Apart from the Intelligence Server, there are other two server components that connect to the information delivery face of the architecture. These servers are MicroStrategy Web and Mobile. The software components of MicroStrategy Web and Mobile are deployed and published using a web server such as Tomcat or IIS. These two communicate with the MicroStrategy Intelligence Server in order to deliver information to the corresponding Web and Mobile client counterparts.