It reminds me about ZBXNEXT-1791 where discussion is for nodata() function for an unsupported item.
But core logic is the same - how we can return a value for a function if we don't have reliable basic data.

nodata() is a bit special case even for unsupported items, though - we have a reliable fact that there is no data

Yeah, I agree with you, which means that the ZBXNEXT-1791 should be fixed first order, because it's more big evil

This problem is not about nodata() function, str() is the cause of trigger evaluation error when nodata() works. I think ZBXNEXT-1791 is different issue.

Is there an option of splitting one trigger in two with dependency between them?

I confirmed that regexp() and iregexp() have same problem.

CONFIRMED

Related issue ZBX-9913.

Also changed sum() function to return 0 if there are no data in the requested range.

Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-10312

(1) I believe this change should be listed on upgrade notes.

wiper of course, what's new, upgrade notes and maybe also to supported trigger functions.

wiper Documented:

• 2.2
  • https://www.zabbix.com/documentation/2.2/manual/introduction/whatsnew2213
  • https://www.zabbix.com/documentation/2.2/manual/installation/upgrade_notes_2213
• 3.0
  • https://www.zabbix.com/documentation/3.0/manual/introduction/whatsnew303
  • https://www.zabbix.com/documentation/3.0/manual/installation/upgrade_notes_303

Note that in some places (for example 2.2 manual/introduction) the item order is messed up, probably because of different level top headers used in them. For example:

===== -#7 What's new in Zabbix 2.2.2 =====

and

==== - #2 What is Zabbix ====

sasha CLOSED

Successfully tested.

To reproduce the expression must contain time function such as nodata() or two items - one for which there are values and another one for which there are no values. Trigger expressions are evaluated for the items that are being synchronized to DB or in timer process.

Other observations:

• short-circuit logic operators would be useful in such case, e.g. "nodata(300)#1 && str(pattern,300)" would not evaluate str() if nodata() was true;
• for other functions that can be used with time interval in seconds it is ambiguous what to do in case of no data (what is the maximum, minimum, average of 0 values?).

Released in:

• pre-2.2.13rc1 r59547
• pre-3.0.3rc1 r59548
• pre-3.1.0 r59549