Even though Zabbix is a mature product with more than 15 years behind it, it is still very actively developed. Bugs are fixed and new features are added. At some point, accumulated improvements make it worth upgrading. In this section, we will look at the following:
General version policy: Which versions are stable and which ones are supported for longer periods of time
The upgrade process: What can be upgraded to what and how it should be done
Compatibility between Zabbix components: Which versions of the server can be used with which versions of the agent and so on
The Zabbix versioning scheme has changed a few times over the years. In general, the first two numbers have denoted a major version, such as 2.4 and 3.0, while the third number has denoted a minor version number. Previously, an even second number denoted a stable branch, while an odd second number denoted a development branch. Thus, 2.3 was a development branch for 2.4, while 2.4 was the...