[#ZBXNEXT-552] More mathematical functions to trigger and calculated item expressions

[ZBXNEXT-552] More mathematical functions to trigger and calculated item expressions Created: 2010 Nov 08 Updated: 2021 Jun 03 Resolved: 2021 May 21
Status:	Closed
Project:	ZABBIX FEATURE REQUESTS
Component/s:	Server (S)
Affects Version/s:	1.8.3
Fix Version/s:	5.4.0

Type:

Change Request

Priority:

Major

Reporter:

Jori Hämäläinen

Assignee:

Unassigned

Resolution:

Fixed

Votes:

Labels:

calculateditems, patch, triggerfunctions, triggers

Remaining Estimate:

Not Specified

Time Spent:

Not Specified

Original Estimate:

Not Specified

Environment:

LAMP with Zabbix 1.8.3

Attachments:

0001-frontends-php-add-power-operator-support-for-trigger.patch

0001-zbxalgo-add-power-operator.patch

zbx_expression.c_pow_sqrt.patch

Issue Links:

Causes
causes	~~ZBXNEXT-6544~~	New set of operators, mathematical an...	Closed
Duplicate
duplicates	~~ZBXNEXT-1444~~	Zabbix Lua Master Ticket	Closed
is duplicated by	~~ZBXNEXT-1388~~	additional operations for calculated ...	Closed
is duplicated by	~~ZBXNEXT-3486~~	new function for triggers - absolute(...	Closed

Description

For statistical analysis of collected/polled Zabbix data some formulas needs to be used.

Variance needs ability to add to power of 2. (X ** 2 or X^2)
Standard deviation needs square root (of variance). ( SQRT(X) or X**0.5 or X^0.5)

Perhaps some others might need to have LN, LOG, EXP etc.

Example use case:
Cisco routers provide SLA monitoring and SNMP MIB returns NumberOfMeasures, SumOfMeasures and SumOfMeasuresSquared. From these 3 variables I can calculate

average RTT
variance of RTT
standard deviation of RTT

Unfortunately only last (standard deviation) needs to be calculated with external program as according to manual Zabbix does not support SQRT-function.

Also power could be used to combine two 32-bit counters to one 64-bit: counter + counterHigh*2^32 instead of counter + counterHigh*4294967296..

Luckily PHP has SQRT() and POW() for web interface based square rooting and powering. C++ math.h also has it. So it should not be that big thing or?

Comments

Comment by Jacobo Aragunde Pérez [ 2011 Jan 26 ]

I also need this functionality, and I'd like to try to contribute with a patch before implementing it as a part of my custom agent. Is somebody already working on this? Any advice on how to start?

Comment by richlv [ 2011 Jan 26 ]

that would be more in server not agent, though, wouldn't it ?
in any case, you might want to talk to nelsonab (freenode/#zabbix), he was playing around with lua integration

Comment by Jacobo Aragunde Pérez [ 2011 Jan 26 ]

Yes, I meant, I'd prefer to contribute with a patch to the server, and if not possible, I'd implement those operations in my custom agent, before sending the values to the server.

Comment by Vladimir Kravchenko [ 2012 Sep 01 ]

patch zbx_expression.c_pow_sqrt.patch for 2.0.3rc1, '^' = pow(), '2 ~' = sqrt()

Comment by Alexei Vladishev [ 2014 Sep 25 ]

[ZBXNEXT-552] More mathematical functions to trigger and calculated item expressions Created: 2010 Nov 08 Updated: 2021 Jun 03 Resolved: 2021 May 21