Dependencies between resources
TADDM discovers and categorizes several types of cross-tier dependencies, these dependencies are reflected in the CDM. Dependencies model the runtime relationships among the various components within the CDM.
There are several types of dependencies, including:
- Transactional dependencies
Transactional dependencies occur between application components, such as web servers, application servers, and databases. The dependent component issues requests to the provider component in order to perform certain functions. For example, a Java™ Database Connectivity (JDBC) connection from a Java 2 Platform, Enterprise Edition (Java EE) server to a database is a transactional dependency. In this case, the provider is often called a server and the dependent called a consumer or client.
- Service dependencies
Service dependencies occur between application components and infrastructure services, such as Domain Name System (DNS), Lightweight Directory Access Protocol (LDAP), and Network File System (NFS). The provider is the infrastructure service, and the dependent component requests system services from the provider. For example, a request to map a DNS name to an IP address.
- IP dependencies
IP dependencies occur between two computer systems or between an application server and a computer system. TADDM creates this type of relationship when it discovers a relationship between two computer systems but cannot discover exactly which application server is involved.
- System dependencies
System dependencies occur between an application server and its host computer system.
- Application to application dependencies
Application to application dependencies occur from one business application to another business application.
Example of dependencies
- Computer system (CS1) hosts an application server (AP1) and process (P1)
- Computer system (CS2) hosts an application server (AP2) and process
There are two logical connections created by TADDM: AP1 <-> AP2 and P1<->P2