New operand XOR or MAX 1

[slalomsk8er]

Expected Behavior

I would like to define a node in which only one of 2 children is allowed to be OK at the same time.

CRITICAL + CRITICAL = CRITICAL
OK + CRITICAL = OK
CRITICAL + OK = OK
OK + OK = CRITICAL

Current Behavior

OR works for the first 3 cases.
MIN 1 works for the first 3 cases.
NOT works for the last 3 cases.

Possible Solution

Addition of a new operand - XOR or MAX 1.

Context

I have identical checks for a service on 2 servers but only one is allowed to run.
If both run race conditions and duplication of data could occur.

[nilmerg]

Hi,

thanks for the suggestion. That's definitely something I think is a good addition. Though, for now there's no chance it goes into the upcoming release. Maybe the next.

In case you can't wait, try this:

A = localhost;Hoststatus
display 0;A;A

NOT A = ! A
display 0;NOT A;NOT A

B = test-down-1;Hoststatus
display 0;B;B

NOT B = ! B
display 0;NOT B;NOT B

NOT A AND NOT B = NOT A & NOT B
display 0;NOT A AND NOT B;NOT A AND NOT B

NOT (NOT A AND NOT B) = ! NOT A AND NOT B
display 0;NOT (NOT A AND NOT B);NOT (NOT A AND NOT B)



A and B = A & B
display 0;A and B;A and B

NOT A AND B = ! A and B
display 0;NOT A AND B;NOT A AND B

XOR = NOT A AND B & NOT (NOT A AND NOT B)
display 1;XOR;XOR

🤣

[markuslf]

On my machine, the config workaround shown does not work for the scenario described above. The root node becomes CRITICAL if any of its nodes are CRITICAL, but should be OK.

[nilmerg]

Hm, works still fine for me:

All OK	All CRITICAL	One OK One CRITICAL

[markuslf]

Strange... the workaround currently works for me too. Don't know what I have tested. I'm pretty sure it didn't work yesterday.

Nevertheless, I have submitted a pull request to implement "MAX 1" for the current development version.