1. Aim
The aim of a user service is to support high-level monitoring, to ensure that services used by users: messaging, Internet access, printing... etc, are in good operational order and to be able to calculate availability rates and thus commit to agreed SLAs.
In order that user services be most relevant to the customer it is recommended to define them in association with the customer prior to the the monitoring deployment phase.
The Rules
The status of a user service (US) is dependent upon the statuses of the elements that comprise it and according to the rules listed below:
- If a US has at least one 'blocking' element that is Out of Use/DOWN/CRITICAL, then the US is Out of order.
- If a US has at least one 'blocking' element that is Unknown, and if there is no 'blocking' element in status out of use/DOWN/CRITICAL, then the US is in status UNKNOWN.
- If a US consists only of 'degrading' elements, if all elements are in an Out of Order/DOWN/CRITICAL state then the US is Out of order.
- If all the elements of a US are in indeterminate then the USis in status UNKNOWN.
- If at least one 'degrading' element is in status Out of Use/DOWN/CRITICAL or WARNING or UNKNOWN, then the status of the US is Degraded
Thanks to these rules and monitored elements, ServiceNav lets you to design a model of the operation of any business application, network architecture, system architecture,...
2. Creating a user service
To create a new user service go to : Configuration > User Service then click on " + Add
2.1 Configuration of general information
- Provide the which will be visible in IT Weather to all users.
- Optionally insert more information in the description field if necessary.
- Choose in the field " Associated with " the company/site the user service is relevant to.
- Select a Period of availability ; the time period over which you wish to calculate availability.
- Set, as a percentage, the availability rate you wish to achieve, calculated over the selected availability period.
- Show or Hide, allows you to choose whether the user service is visible in IT Weather.
- Select the criticality of the user service to the customer
2.2 Notification configuration
- NotificationEnable or disable notifications for this user service.
- Type of notification : Choose the events for which the user service will notify the contacts defined below
- Contacts/Contact Groups : Select contacts to be notified. The list on the left contains the available contacts and the list on the right contains configured groups of contacts.
2.3 Configuration of user service dependencies
- choose the user services on which the one being created will depend. The lists contains available, existing user services. Depending on its impact it will be set as either "blocking" or "degrading".
- choose the hosts on which the US will depend. The lists contain the available hosts. Depending on the impact of the selected hosts,they are set to either "blocking" or "degrading".
- choose the services on which the US depends. The lists contain the available services. Depending on the impact of the selected service, it will be set to either "blocking" or "degrading".
3. Designing a user service
We will, through a worked example, deconstruct the implementation of a user service.
3.1 Environment
Infrastructure : we have two Windows servers running a resilient Active Directory, SRV CD1 and SRV CD2.
3.2. Service to be designed
We want to create a user service that represents the overall operation of the service " Active Directory ". This is provided by two different servers in order that it have redundancy.
3.2.1. Step 1: Define the final user service.
3.2.2. Step 2: Define the elements necessary for the proper operation of the user service.
SVR CD1 : represents the properly functioning first server providing active directory services.
AD-check on CD1 : represents the properly functioning first active directory service.
SVR CD2 : represents the properly functioning second server providing the active directory services.
AD-check on CD2 : represents the properly functioning second active directory service.
3.2.3. Step 3: Building the sub-user services
Q: When is my user service operational?
A: It is operational when the first service active directory is OK, AND/OR the second service active directory is okay, and vice versa.
Q: When is my user service down?
A: It is down when both active directory services are down.
Q: How does each of the "active directory" services work?
A :
Directory-CD1 : works ONLY if host "SRV CD1" AND service "AD-check on CD1" are functional. Both of them are mandatory for the proper functioning of the user service. Their relationship with the user service will therefore be of the "Blocking" type.
Directory-CD2 : works ONLY if host "SRV CD2" AND service "AD-check on CD2" are functional. Both of them are mandatory for the proper functioning of the user service. Their relationship with the user service will therefore be of the "Blocking" type.
The rule that applies is:
If a US with at least one blocking relationship component is Out of Use/DOWN/CRITICAL, then it is Out of Order.
Creating sub-user services is not always necessary, depending on the complexity of the user service designed.
3.2.4. Step 4: Defining the relationship of sub-user services
The sub-user services each represent the operation of an active directory service. For users to have access to information system resources (mail, network shares, etc.), at least one of the two user sub-services must be functional. They therefore have a "degrading" relationship with the top level user service. If one of the two sub-user services is out of order, then the Directory user service will be in degraded status based on this rule:
If at least one degrading element is in status Out of use/DOWN/CRITICAL or WARNING or UNKNOWN, then the status of the US is Degraded.
On the other hand, if the two sub-user services are in out of use status then the following rule applies:
If a US consists only of degrading elements, if all the components are in an Out of Use/DOWN/CRITICAL state then the US is Out of Use.
Using these rules we can model the redundancy and operation of any business application.
4. Questions to ask before creating a user service
Put yourself in the place of the customer when asking yourself the following questions:
What IT services are necessary to meet the company's operational needs?
This question is used to determine the user services to be created.
When is the service not available to the user?
This question helps to understand the technical operation of a service. The idea is to identify all the monitoring checks to implement, as well as their impacts on the service (blocking or degrading) in order to model the user service accurately. Once this question has been answered, it is necessary to configure the monitoring in order to have the right information.
When is the service used?
The response defines the time period that will be configured for the "availability period" parameter, which is used to calculate the availability rate.
What is the agreed availability (percentage) to be achieved - SLA?
this reflects the level of service desired by the customer. This level must be defined contractually, according to the customer's needs, its infrastructure, and the service it has purchased.
