We're getting closer to sending in our slightly fake data, but we must configure IT services before the data comes in. In Zabbix, SLA results cannot be calculated retroactively. IT services must be configured at the beginning of the period for which we want to collect the SLA. SLA state is stored separately from trigger and event information, and is calculated at runtime by the Zabbix server.

Let's go to Configuration | Services. The interface for managing Services is different from most other places in Zabbix. We have root, which is an immutable entry. All other service entries must be added as children to it. Click on Add child next to the root entry.

We'll start by grouping all customer services in an entry—we might have internal services later. In the Name field, enter Customer services and click on the Add button at the bottom.

We have two customers; click on Add child next to Customer services. Enter Banana in the Name field, enable the Calculate SLA checkbox, then click on Add.

Click on Add child next to Customer services again. Enter Pineapple in the Name field, enable the Calculate SLA checkbox, then click on Add. Notice how the Customer services entry can be expanded now. Expand it and observe the result, which should be like this:

The customers are in place; let's add their services now. Click on Add child next to Banana. Enter Code repository in the Name field and enable the Calculate SLA checkbox. This will be our leaf or lower-level service, and we'll now link it to a trigger. The trigger state will affect the SLA state for this service and for all upper-level services with SLA calculation enabled. Click on Select next to the Trigger field, then click on Code repository down in the Name column.

The final configuration for this service should look like this:

When done, click on Add. Then, click on Add child next to Banana again. Enter Ticketing in the Name field, enable the Calculate SLA checkbox, and click on Select next to the Trigger field, then click on Ticketing down in the Name column. Click on the Add button to add the second child service for this customer.

Our first customer is configured; now, click on Add child next to Pineapple. Enter Warehouse analytics in the Name field, enable the Calculate SLA checkbox, and click on Select next to the Trigger field. Click on Warehouse analytics down in the NAME column then click on the Add button.

We can add the ticketing service as another child service for Pineapple, but services here can also be defined once, then added at multiple places in the service tree. This is done by making parent services depend on additional services. Click on Pineapple and switch to the Dependencies tab. Notice how its only child service, Warehouse analytics, is already listed here. Click on the Add link and click on Ticketing entry. Click on the Update button:

That didn't work well. If you're familiar with filesystem concepts, the error message might be a bit helpful; otherwise, it's probably a very confusing one. IT services in Zabbix have one hard link; they're attached to a parent service. To attach them to another service, we add them as a dependency, but we have to add them as a soft link, as only one hard link is allowed per service. Mark the SOFT checkbox next to Ticketing and click on Update again. This time, the operation should be successful and the Ticketing entry should now be visible for both companies.

If the entries are collapsed for you, expand them all and observe the final tree:

Note that we enabled SLA calculation starting from the company level. Computing the total SLA across all customers is probably not a common need, although it could be done. In the Status calculation column, all of our services have Problem, if at least one child has a problem. In the Service properties, we could also choose Problem, if all children have problems. At this time, those are the only options for problem state propagation; setting the percentage or amount of child services isn't possible (it could be useful for a cluster solution, for example).