With all of the log monitoring items collecting data, let's take a quick look at the displaying options. Navigate to Monitoring | Latest data and click on History for Second logfile. Expand the Filter. There are a few very simple log viewing options here:

The field in the preceding screenshot is explained as follows:

• Items list: We can add multiple items and view log entries from them all at the same time. The entries will be sorted by their timestamp, allowing us to determine the sequence of events from different log files or even different systems.
• Value and Selected: Based on a substring, entries can be shown, hidden, or colored.

As a quick test, enter error in the Value field and click on Filter. Only the entries that contain this string will remain. In the Selected drop-down menu, choose Hide selected and now only the entries that don't have this string are shown. Now, choose Mark selected in the Selected drop-down menu and notice how the entries containing the error string are highlighted in red. In the additional drop-down menu that appears, we can choose red, green, or blue for highlighting:

Let's add another item here; click on Select behind the Items list entry. In the popup, choose Linux servers in the Group drop-down menu and A test host in the Host drop-down menu, then click on First logfile in the Name column. Notice how the entries from both files are shown, and the coloring option is applied on top of that.

That's pretty much it regarding log viewing options in the Zabbix frontend. Note that this is very limited functionality and, for a centralized Syslog server with full log analysis options on top of that, a specialized solution should be used; there are quite a lot of free software products available.