Are Alerts for CPU/RAM based on the data from statistics polling interval? Or do alerts do their own polling?

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I have some alerts that look at CPU and RAM every minute and send an email if CPU or RAM has been above 90% for 5 minutes.

But I notice the polling interval for statistics is 10 minutes.

So I'm trying to understand if the alert is using information gathered from the 10 minute polling interval for node statistics, and if that is the case, then it doesn't make a lot of sense for me to have an alert checking every minute. 

Basically, I'm trying to give the Business some idea of how accurate the alerts are.

What we're trying to alert on is when the CPU or RAM has been sitting at above 90% (critical threshold) for over 5 minutes but I am not knowledgeable enough about the product to understand whether the alert is working the way we expect it to, assuming it is pulling data gathered from the node statistics polling interval.

 

shuth

The alerts reference the database therefore are based on your polling intervals.

When you set a "condition must exist for X" time in an alert, it should be higher than your polling interval to ensure you have at least 2 data points otherwise you are just delaying the alert trigger by that amount of time.

A rough example:

• T0 - Alert checks database for nodes with CPU/RAM > 90% - no nodes match
• T0.5 - System polls and returns Node A at 94% memory
• T1 - Alert checks database for nodes with CPU/RAM > 90% - Node A matches, start 5 min timer
• T2 - Condition still matches
• T3 - Condition still matches
• T4 - Condition still matches
• T5 - Condition still matches
• T6 - Condition still matches - Trigger alert
• T7
• T8
• T9
• T10
• T10.5 - System polls and returns Node A at 75% memory

You can configure your alerts to trigger for time periods greater than 10 mins, or you can reconfigure your statistics polling to every 5 minutes instead of 10 minutes. Depending on the size of your environment, the latter may have some impact on database size, system performance, and polling capacity.