Zabbix vs grafana vs kibana

Zabbix is a monitoring solution, which works with active+passive agents, which can "measure" things on your systems. Based on those measured values, you can take actions/alerting etc. In addition, it plots nice graphs with disk/CPU etc. usage

Kibana/Grafana, on the other hand, do get the information from logs sent from your systems. They do not actively monitor things and also alerting/messaging is not their main focus. (If possible at all...?) They are, however, great at digging through all your log files.

So in short:

• Active/Passive Monitoring + Alterting = Zabbix
• Centralized metrics visualiser = Grafana/Kibana

It's not one or the other. You can combine them.

Zabbix - complex monitoring solution including data gathering, data archiving (trends, compaction,...), visualizer with dashboards, alerting and some management support for alerts escalations. (have a look at collectd, prometheus, cacti. They are all able to gather data)

Grafana - visualizer of data. It can read data at least from prometheus, graphite and elastics. Its primary goal is to visualize things in user defined dashboards and correlate things from possibly various sources. You can for example see cpu load (float time serie data from prometheus for example) with nice annotations referring to some special event in log file (loaded from elastics of course)

Kibana - visualization + analytics on logged data into elastics. Have a fast look at kibana discover to get idea. It is "must to have" tool when you need to search your logs (various services, various servers) in one place.