Introduction:
- Service Mapping enables IT departments of companies, organizations, and cloud companies providing platform as a service to create a service-aware view of infrastructure.
- Service Mapping is not about creating and updating configuration items in the CMDB, but also having the topology stored in the CMDB related to the service.
- Service Mapping discovers services in an organization and builds a comprehensive map of all the services, applications and configuration files used in the services. All the software and hardware components are placed in the ServiceNow CMDB as part of this process.
- In addition there is also a service map built for each service referencing the hardware and application Cis that make up the service.
Service Mapping features:
- Service Mapping is agentless meaning that there is not a requirement for software to be installed on target devices.
- However to enable the agentless discovery, there will be credentials required.
- Service Mapping is service centric meaning thereby that it only discovers configuration items (CIs) relevant to the defined service.
- This is where it makes a difference of top-down service-mapping and bottom-up discovery of horizontal and infrastructure mapping.
- Service mapping is configuration based, doesn’t have to rely on traffic back and forth between items, which means that the mapping would go to the same places where applications within a service would go to and find information about what other applications are being leveraged, connected to or referenced to.
Note - Instead of the bottom up approach, service mapping uses the top down approach.
Instead of discovering 10 different Apache servers on a particular host, service mapping uses the top down approach specifically to a particular service, further discovering that it is supported by a particular Apache web server which in turn leverages information from a WebSphere app server, so forth and soon.
A service
- A set of interconnected applications and hosts configured to offer a certain service to an organization.
- Consider the simple example of Home which provides the shelter service.
- Shelter service is supported by critical services like electrical service which in turn is supported by its components like the meter, service panel, breakers, fuses, the wires and junction boxes.
- Similarly there are other critical services like the Plumbing service, etc. which is again supported by its underpinning services.
- Mapping the most critical underpinning services is the best starting point.
In the IT world, the below diagram explains few examples of service mapping:
- Consider the example of a stock trader service.
- A company has a way for their employees to put in orders for trading stock of the company itself.
- In order for the customers to be able to engage with the stock trader service, they would go to a URL.
- One that URL is navigated to, there is an IIS server that is supporting the URL that is hosted on a Windows Server.
- There may AGAIN be a Microsoft SQL database, which is storing the user information, the transaction information and the order information.
- All the CIs are supporting the stock trader service.
- A service mapping service map would then:
- Start with the discovery of the URL. (CI - 1)
- Then find that the URL is supported by a specific IIS instance. (CI - 2)
- And also find that the URL is hosted on a particular host. (CI - 3)
- Then it is seen that there is a connection from that IIS server to a Microsoft SQL Server (CI - 4)
- The Microsoft SQL Server is hosted on a different host, not CI- 3. (CI - 5)
- So, in this example we could see an entry point (URL) and the configuration files of the initial application being explored to see connections to other applications, CIs and hosts.
I will certainly come back with more about the Service Mapping implementation and other best practices around it, as and when I progress through the exercise currently in progress in our organization.
Hope this short info serves as good start to your journey of understanding Service Mapping.
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Regards,
Anish Reghu
