Linux

Could you provide an example of trigger expression and some details of item configuration?

"{Template_BRT TPDIN Web Monitor:tyconDINBattery_Amperage.avg(2m)}<-0.5" works as expected and the trigger line in the latest data graph is correctly displayed at -0.5A. "{Template_BRT TPDIN Web Monitor:tyconDINBattery_Amperage.avg(2m)}<-.5" displays the trigger line at (+)5.0A, ignoring both the decimal point and the negative sign. "{Template_BRT TPDIN Web Monitor:tyconDINBattery_Amperage.avg(2m)}<.5" also displays the trigger line at +5A. (not 0.5A, but 10x that, ignoring the decimal point).

This is used to detect power failures as we can't directly monitor AC input (no sensors).

The average function doesn't seem to be needed as the sensors aren't particularly noisy.

So the issue is about frontend displaying wrong thresholds in graphs?

and - it seems, actually triggering on the wrong value (but that's a bit harder to be sure of since almost every power failure results in a charge cycle which puts 10A into the batteries and would trip the +5A trigger as well.

I think it was fixed in 3.4 and higher versions as a part of ZBX-11470.

If it annoys you too much, here are the changes that were made to frontend:

Index: trunk/frontends/php/include/classes/macros/CMacrosResolverGeneral.php
===================================================================
--- trunk/frontends/php/include/classes/macros/CMacrosResolverGeneral.php       (revision 65319)
+++ trunk/frontends/php/include/classes/macros/CMacrosResolverGeneral.php       (revision 65320)
@@ -63,8 +63,12 @@
                // Replace functionids with string 'function' to make values search easier.
                $expression = preg_replace('/\{[0-9]+\}/', 'function', $expression);
 
+               // Replace whitespace with emptyness to make value search easier.
+               $expression = str_replace(" \r\n\t", '', $expression);
+
                // Search for numeric values in expression.
-               preg_match_all('/'.ZBX_PREG_NUMBER.'/', $expression, $values);
+               preg_match_all('/((?<![\)\.0-9]|[\.0-9]['.ZBX_BYTE_SUFFIXES.ZBX_TIME_SUFFIXES.']|function)\-?'.
+                               '([.][0-9]+|[0-9]+[.]?[0-9]*)['.ZBX_BYTE_SUFFIXES.ZBX_TIME_SUFFIXES.']?)/', $expression, $values);
 
                $macro_values = [];
 

Ah OK - I'm on 3.2.11. I'll check after update.

Updated to 3.4.7 - I still see the issue.

If I change the trigger from value from "-0.5" to "-.5 just by deleting the "0" the trigger line moves from negative one half A to positive five A. Adding the leading zero restores the correct position.

it is easy enough to work around, but could be a bit confusing to others, as it was to me initially.

Indeed, just checked it in trunk. A correct value is extracted from trigger expression, but for some reason the threshold is drawn incorrectly.

In frontends/php/include/classes/graphdraw/CLineGraphDraw.php selectTriggers() does

preg_match('/^\{([0-9]+)\}\s*?([\<\>\=]{1})\s*?([\-0-9\.]+)([TGMKsmhdw]?)$/', $trigger['expression'], $arr)

and then

convert($constant)

while convert() (in frontends/php/include/triggers.inc.php) does

preg_match('/(?P<value>[\-+]?[0-9]+[.]?[0-9]*)(?P<mult>['.ZBX_BYTE_SUFFIXES.ZBX_TIME_SUFFIXES.']?)/', $value, $arr)

The last one should be:

preg_match('/(?P<value>[\-+]?[0-9]*[.]?[0-9]*)(?P<mult>['.ZBX_BYTE_SUFFIXES.ZBX_TIME_SUFFIXES.']?)/', $value, $arr)
//                                ^

to allow numbers starting with ".", but unfortunately it will also match empty string. So a more sophisticated regular expression is needed.

(1) [F] No translation strings changes.

iivs CLOSED

Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-13500

Fixed in:

• 3.0.17rc1 r79427
• 3.4.9rc1 r79429
• 4.0.0alpha6 (trunk) r79430