CMDB: Understanding dependencies between configuration items

It is important for an enterprise to know about its IT environments, which includes out-of-date inventory and configuration data. CMDB plays a crucial role in aligning these data, enabling an organization to discover, plan, deliver and manage IT capabilities across their entire enterprise.

A CMDB is a database that contains information about the configuration of your IT environment. A CI is any equipment, software application, or service that can be used to build or run an IT system. Each CI represents a related set of data. 

The CMDB maintains relationships between CIs and documents the interactions between them. For example, a server may have several dependencies on other servers or applications installed on it. IT staff members responsible for maintaining the network’s stability and performance levels need to track these dependencies.

The most important concepts in the CMDB

The CMDB is used to find all the configuration items relevant for a particular system. This helps identify missing or duplicated components, preventing confusion down the road.

The most essential concepts in a CMDB are:

• Configuration Items (CI): These are the assets that make up your environment, like hardware, software and people. They’re organized into hierarchies based on how they relate to each other; for example: “Computer” is under “Hardware.
• Dependencies: A dependency is an association between two CIs that requires both CIs to work together correctly. For example, if you want one computer without its operating system installed on it, then this would be considered an invalid state since they’re dependent on each other.
• Relationships: These indicate how two CIs interact with one another (e.g., “Software” has “License Key”) as well as what data exists within them (e.g., OS version number).

Relationship with other CMDB components

The relationship between CIs is an important aspect of CMDB, because it can help you determine how CIs are related and what kind of dependency they have. For example, if an application server is dependent on a database server, then there is a good chance that the application server will need to be replaced whenever the database server needs to be upgraded or replaced. 

On the other hand, it may not make sense for a firewall to be dependent on an application server; this would make the firewall less flexible than necessary for your organization’s needs.

The relationships between items can also provide insight into their dependencies: if two items have no relationship with each other (other than being in different groups), this indicates that there is no direct relationship between them (such as one existing only when another does). 

In contrast, if two items have many relationships with each other (both being part of many groups), then this indicates that there might be some sort of dependency between them. For example, if two machines share licensing information and both require frequent updates in order to function properly at all times.

Read: Why a custom CMDB is what your organization needs?

Differences between CI relationships and CI dependencies

The CI relationships and dependencies are important parts of the CMDB. Both are used to determine what is needed to be changed in order to update a specific configuration item (CI).

What are configuration item (CI) relationships?

Configuration item relationships are used to define the relationship between two configuration items.

When you create a new configuration item, it can be related to one or more existing configuration items. These relationships define how two or more configuration items interact with each other and can help you understand how the components of your environment interact with each other. 

For example, if you have two servers that are running the same application, they may both depend on an OS and database server at a minimum level of support. In addition they may also share common patches and updates that need to be applied together.

Why do you need to define CI relationships?

The CMDB is a necessity for any organization that manages software configurations. A CMDB helps you understand how different configuration items are related to each other, how changes to one configuration item will affect other configuration items, and how changes to one group of configuration items may affect another group of configuration items.

CI relationships and their associated attributes are the key to making sense of the meaning and function of your CMDB, in accordance with your needs. 

A CMDB without relationships means that you are operating a database of CIs, which would make finding and understanding inter-dependencies difficult. With relationships, users can understand how one CI may affect another, and if a failure causes impact, they will be able to detect and prevent further damage by isolating affected devices.

What are configuration item (CI) dependencies?

Configuration item (CI) dependencies are a type of CI relationship. They’re used to define the impact of changes to one CI on another. Specifically, they help identify the impact of changes to one CI on another.

Here’s an example: If a change is made to the network infrastructure for your company, you may need to make some changes in order for it to work properly with your new internet provider. The configuration items affected by this change could include DNS entries and firewall rules that have been changed because of it.

A solid CMDB will provide an understanding of dependencies between your IT assets. This allows you to work with your IT assets more efficiently by knowing how they’re likely to react when something changes or breaks down. For example: If a database server goes down because its hard drive crashed, it could potentially cause downtime across all applications running on that database server (e.g., inventory management). 

Why do you need to define CI dependencies?

CI dependencies are used to ensure that changes to one CI do not affect others. For example, if you have a change control policy that defines “Required” and “Recommended,” then when someone makes a change to their configuration item (CI), they must also make sure that this change is required for other CIs.

If there were no dependencies defined for your configuration items, then any changes made would simply be applied immediately without regard for whether or not they might impact other CIs in your environment. 

In some cases where the impact analysis doesn’t occur until after deployment or testing has occurred, this could result in missed errors or failures due to misconfigured configurations being deployed into production.

Read: How to determine CMDB accuracy?

When should you configure CI relationships and CI dependencies?

There are two types of relationships that you can use to define relationships between configuration items:

• Configuration item relationships (CIRs)
• Configuration item dependencies (CIDs)

CI relationships can be used to define the relationship between CI instances, while CIDs can be used to establish a dependency between CIs. A CI relationship is not required for a CID. However, there are important differences between the two that make it crucial that you understand when each is applicable in your CMDB.

CMDBs can be used to help enhance your awareness of dependencies between the technology items in your organization. The dependencies between CIs usually indicate a relationship between them. For example, one CI might be a “parent” of multiple “child” CIs. Or one CI might be hosted on another CI and thus have a dependency on that host. 

Those types of dependencies are key in understanding the full scope of technology as it impacts your business processes, or vice versa.

What is the difference between CI dependencies and CI relationships?

The relationship between two configuration items is defined as the interdependencies between them. A relationship can be directional or non-directional. If you define a dependency between two configuration items, it means that if a change is made to one of them then changes must be applied to both of them in order for the product to remain consistent. 

The common types of relationships are:

Using IT discovery to understand CI dependencies

A mature CMDB allows IT professionals to discover and label their network components. This information can be used to establish visual relationships between configuration items, creating an organization-wide view of the dependencies between CIs.

Automated discovery helps IT pros discover CIs and visually map relationships between CIs so they can better understand how they all fit together. This insight can help them make better decisions and manage resources more effectively.

The CMDB contains information about which servers, applications, and databases are dependent on one another. This can give you instant insight into all the changes that need to be made, who approved those changes and when, and how long the impact will last. If a server needs rebooting to address an issue, the CMDB will show you all of the dependent services and apps that need to be disrupted too.

Understanding dependencies between configuration items is a critical aspect of incident and problem management. By using CMDBs to automatically discover assets in the service desk, combined with ITIL practices and visual relationship mapping, organizations can ensure that they are well equipped to develop thorough incident, problem, and change management processes.

IT discovery tools will automatically tell you what hardware and software assets you have, how they are configured and connected, and who owns what. They can also help populate your CMDB automatically by eliminating the need for manual input of configuration data as it’s collected.

Configuration data is dynamically updated during IT discovery. Automatically synced with your CMDB, this configuration data is updated as soon as it changes in the network inventory. This ensures that the entire lifecycle of a configuration item can be kept up-to-date to prevent conflicts when duplicating items between sites and ensuring compliance with your organization’s security policies.

Experience seamless CMDB management with Virima Discovery

Configuration management is an important aspect of any project, and the CMDB is a key component of that process. 

Eliminate the technical limitations of your CMDB and service lifecycle management by leveraging automated discovery and data transformation from Virima. Your CMDB will never be the same with our modern, user-friendly visual interface that lets you explore and understand the services in your environment. Easily view relationships, dependencies, and availability status with intuitive dashboards and ViVID Services Maps as well as comprehensive reporting.

Virima Discovery when paired with Virima’s CMDB provides a complete holistic view of the IT environment, allowing you to easily discover and document all necessary relationships between assets and applications. 

From service relationships with underlying infrastructure devices, to cloud and container services, Virima Discovery automatically maps the dynamic relationships between IT assets. It enables security analysts to quickly identify vulnerabilities at a glance, helping IT teams prioritize response by correlating real-time changes with identified assets, services and relationships.Know how to integrate Virima Discovery and ViVID Service Mapping with your existing CMDB and other interesting facts about Virima CMDB by scheduling a demo.