Since this book is focused on a large environment, we need to define or at least provide basic fixed points to identify a large environment. There are various things to consider in this definition; basically, we can identify an environment as large when:
There are more than one different physical locations
The number of monitored devices is high (hundreds or thousands)
The number of checks and items retrieved per second is high (more than 500)
There are lots of items, triggers, and data to handle (the database is larger than 100 GB)
The availability and performance are both critical
All of the preceding points define a large environment; in this kind of environment, the installation and maintenance of Zabbix infrastructure play a critical role.
The installation, of course, is a task that is defined well on a timely basis and, probably, is one of the most critical tasks; it is really important to go live with a strong and reliable monitoring infrastructure. Also, once we go live with the monitoring in place, it will not be so easy to move/migrate pieces without any loss of data. There are certain other things to consider: we will have a lot of tasks related to our monitoring system, most of which are daily tasks, but in a large environment, they require particular attention.
In a small environment with a small database, a backup will keep you busy for a few minutes, but if the database is large, this task will consume a considerable amount of time to be completed.
The restore and relative-restore plans should be considered and tested periodically to be aware of the time needed to complete this task in the event of a disaster or critical hardware failure.
Between maintenance tasks, we need to consider testing and putting into production upgrades with minimal impact, along with the daily tasks and daily checks.