Content Manager

Content Manager is the IBM Cognos BI service that manages the storage of information related to many running applications in the system. Application like 

• Customer Application Data,
• Configuration Data, 
• Scheduling the Information
• Retrieving or storing the report specification
• Models, 
• Metrics, 
• Reports specifications,
• Reports output 
• Security

Content manager stored information in a content store which is a part of data tier (Tier 3). Information is maintained in a relational database.

One IBM Cognos BI installation may have more than one content manager, each on different computer. One content manager is active at one time and other are on standby.

Dispatcher

The dispatcher starts all IBM Cognos services configured. It also routes the requests given by the gateways. It can route requests to a local services, such as report service, query service, repository

service or system service. This way dispatcher perform load balancing.

It is a multi-thread application, it can use one or more threads per requests. Any configuration change in the application are routinely communicated to all running dispatchers. It also includes  IBM Cognos Application Firewall to provide security for IBM Cognos BI.

When a dispatcher starts, it registers itself with content manager and this way each dispatcher have information about other dispatcher. If one dispatcher fails or unavailable, request for that dispatcher are routed to next available dispatcher until the failed dispatcher re-register itself

Application Tier

The IBM Cognos BI applications tier contains one or more IBM Cognos BI servers. It is responsible for running all the services requested by a gateways. It receives requests from gateways and send it to appropriate service.

Applications Tier Components-

1. Dispatcher, it operates services and routes requests.
2. Content Manager, it manages the storage of customer application data.

IBM Cognos BI server runs requests, eg- report studio, analysis studio, query studio, which are forwarded by a gateway. Apart from that IBM Cognos BI server also renders the IBM Cognos Connection and Metric studio interfaces.

Gateway

    IBM Cognos have below listed gateways-

• CGI-  It is default gateway. CGI can be used for all supported Web servers. To enhance performance or throughput, we may choose other supported gateway types.

• ISAPI-  ISAPI can be used for the Microsoft Internet Information Services (IIS) Web server.  It delivers faster performance for IIS.

• apache_mod- We can use an apache_mod gateway with the Apache Web server.

• servlet- If Our Web server infrastructure supports servlets or we are using an application server, We can use a servlet gateway.

When an IBM Cognos BI gateway receives a request, it perform below tasks-

• It encrypts passwords to ensure security and did not allow unauthorized user to access.
• It extracts information needed to submit the request to an IBM Cognos BI server.
• It attaches environment variables for the Web server.
• It adds a default namespace to the request to ensure that the server authenticates the user in the correct namespace.
• It passes requests to an IBM Cognos BI dispatcher for processing.

Web Server

A Web server is an application designed to receive incoming browser requests and route them to the intended application (eg. Cognos). It is used to get all the information of user (authentication) via gateways.
      The IBM Cognos web server tier may have one or more IBM Cognos BI gateways. Web communication in IBM Cognos BI is typically through gateways. A gateway is an extension of a Web server, it transfers information from web server to application server.

Gateway-

 IBM Cognos BI supports several types of Web gateways.

• CGI
• ISAPI
• apache_mod
• servlet

GUI or User Interface

It is presentation or final level of Cognos which is used by end user, author or administrator. IBM Cognos BI has two type interface.

1. Web-based interfaces-

• Cognos Connection
• Cognos Administration
• Cognos Query Studio
• Cognos Report Studio
• Cognos Analysis Studio
• Cognos Event Studio
• Cognos Metric Studio
• Cognos Workspace
• Cognos Workspace Advanced

2. Windows-based interfaces

• Cognos Framework Manager
• Cognos Metric Designer
• Cognos Transformer
• Cognos Map Manager
• Cognos BI for Microsoft Office
• Cognos Insight

  

Cognos Architecture

IBM Cognos has a multi-tiered architecture. It can be divided into three tiers:

1. Web server,
2. Applications, and
3. Data.

The tiers are separated by network firewalls. IBM Cognos BI user interfaces comes above the tiers.