In Zabbix, templates play a major role in simplifying the configuration and allowing large-scale changes. If you are a proficient user of word processors, you probably use styles. The same concept is used in text, CSS styles for the web, and elsewhere—separating content from the presentation helps to reduce the amount of work required when changes have to be made.

While the comparison to styles might seem far-fetched at first, it actually is similar enough. Just like styles, you can separate a host from the services you provide, and you can define these services in a centralized fashion. In the same way that a word document has a heading style that allows you to change the font size for all headings of that level with one action, templates in Zabbix allow you to change some parameter for all linked hosts, whether direct or nested.

We used several locations that allow us to modify template linkages in Zabbix:

• Host properties: This allows us to link, unlink, and unlink and clear multiple templates from a single host
• Host mass update: This allows us to link multiple templates to multiple hosts, as well as unlinking, or unlinking and clearing, all the previously linked templates (but not unlinking, or unlinking and clearing, a specific template)
• Template properties: This allows us to link and unlink (and clear) linked templates

In the preceding list, we could also talk about templates where we talk about hosts. That would be used when managing nested template configuration.

Macros in Zabbix are like variables—they provide a generic placeholder that is later replaced with a host-specific value. We looked at some built-in macros and also user macros that allow us to define our own variables to have customized items, triggers, and other entities on the host level.

As we saw with all the rearrangement of items and triggers in templates, it is easier to plan a sane template policy before getting to the actual configuration. It is strongly suggested that you sit down and draw at least a very basic hierarchy of monitored things before rushing into the configuration—that will make things easier in the long run.

In the next chapter, we will look at the ways data can be visualized in Zabbix. We'll start with graphs and network maps, and see how various runtime information can be displayed. We will discuss graph customization and usage in detail.