create trigger for a constantly increasing value

[oebele]

As the title says, I've been trying to create a trigger that should fire when the value of an item is increasing and not decreasing during a certain period of time.

How would I do that? None of the predefined expressions seem to do what I want.

[alixen]

Hi,

As the title says, I've been trying to create a trigger that should fire when the value of an item is increasing and not decreasing during a certain period of time.

How would I do that? None of the predefined expressions seem to do what I want.

You could store item variation instead of raw value by selecting "Delta" instead of "As is" as "Store value" option.
You can then define a trigger as:
{host:item.min(period)}>0

Hope this helps
Alixen

[oebele]

Thanks! That was exactly what I was looking for!

[oebele]

I have a new question related to the previous one:

I have an item that has a value of 0 most of the time, but sometimes starts growing and returns to 0 after a while. It's actually a queue of messages that's being filled on one end and tries to deliver them at the other. I need a trigger that fires when the delivery is failing, so when the value of the item stays the same for a certain period and is not 0.

How would I do that? If I store the item as a delta and configure the trigger like this,

{host:item.min(period)}=0

it will fire when the queuesize is 0 and stays that way. If I store it as-is, there's no trigger that will fire correctly, unless I'm missing something?

Anyone have an idea?

[oebele]

trigger for constant value, not zero

I have a new question related to the previous one:

I have an item that has a value of 0 most of the time, but sometimes starts growing and returns to 0 after a while. It's actually a queue of messages that's being filled on one end and tries to deliver them at the other. I need a trigger that fires when the delivery is failing, so when the value of the item stays the same for a certain period and is not 0.

How would I do that? If I store the item as a delta and configure the trigger like this,

{host:item.min(period)}=0

it will fire when the queuesize is 0 and stays that way. If I store it as-is, there's no trigger that will fire correctly, unless I'm missing something?

Anyone have an idea?

[alixen]

Hi,

I have a new question related to the previous one:

I have an item that has a value of 0 most of the time, but sometimes starts growing and returns to 0 after a while. It's actually a queue of messages that's being filled on one end and tries to deliver them at the other. I need a trigger that fires when the delivery is failing, so when the value of the item stays the same for a certain period and is not 0.

How would I do that? If I store the item as a delta and configure the trigger like this,

{host:item.min(period)}=0

it will fire when the queuesize is 0 and stays that way. If I store it as-is, there's no trigger that will fire correctly, unless I'm missing something?

Anyone have an idea?

Store it "As is" and set a trigger like {host:item.min(period)}#0

We use this kind of trigger to monitor Postfix messages queues.
In fact we use {host:item.min(period)}>{$LEVEL}.

Regards,
Alixen

[oebele]

thanks for the response Alixen, I was on holiday, hence the long delay.

Actually the situation is a bit more complicated: I'm not dealing with a Postfix queue that's constantly being filled up, but a queue of sms-messages that gets filled up only at more or less regular intervals, ranging from weekly to daily. The number of messages sent in each run varies wildly, from a few dozen to 20000+.

The difference with an MTA-queue is that the queue may stay at a high level for a few hours, but that doesn't necessarily mean there's a problem.

When delivery is failing, the queue will not decrease anymore and regardless of its actual level (though not 0) a trigger should fire. Is there a way to do that in Zabbix?

[JBo]

Hi,

This is indeed more complicated.

Here is a way to do that:
Create a calculated item that stores variations of SMS queue length:

• Item key : variation
• Item type : Float
• Item formula : last(item) - prev(item)
• Store value : As is

Define a trigger as:

• {host:variation.count(period,0,"gt")} > 0 & {host:variation.count(period,0,"lt")}=0

This trigger will fire up if queue length has increased during period seconds but never decreased.

Hope this helps,
JBo

[oebele]

Thanks, that's very helpful! I will be testing this in the coming week and I'll post here if it's working.

--edit: test report

So, I've been testing this yesterday and today and I had to make a few modifications to get it to fire when the queue has stalled and is stuck at a certain level, too.

The final trigger now has the following form:

Item key : variation <- can be any random string
Item type : Float
Item formula : last(item) - prev(item)
Store value : As is

Define a trigger as:
{host:variation.count(period,0,"ge")} > 0 & {host:variation.count(period,0,"lt")}=0 & host.item.count(period,0,"eq")=0

Also, this took me some time to realise, as I hadn't worked with calculated items before: you need an item to base the calculation on. So you'll end up with two items per queue. Trivial in retrospect, but confusing for me nonetheless.

[rodeur2080]

Hello,

As the title says, I've been trying to create a trigger that should fire when the value of an item is increasing and not decreasing during a certain period of time.

How would I do that? None of the predefined expressions seem to do what I want.

I am trying to do the same thing but I am in version 4.0 LTS. The storage of the delta no longer exists.
Do you have an idea ?

I am looking for a trigger for a constant increase on the last 6 values.

Regards,

[rodeur2080]

I create the trigger by performing a comparison of the last 6 values with function last (# 1> # 2 and # 2> # 3 ...) but it's a bit heavy.
Do you know a simpler solution?