Understanding Update Intervals in Zabbix: Flexible and Scheduling Intervals

When creating an Item in Zabbix, one of the most important settings we need to configure is the Update Interval.

At first, it looks pretty simple. For example, if we set the interval to 1m, Zabbix checks the Item every minute. But in real monitoring scenarios, we don't always want our Items to run at the same interval all the time.

Sometimes we need to collect data more frequently during specific hours, or we may want an Item to run only at a specific time every day.

For these situations, Zabbix provides Custom intervals, including two useful options: Flexible intervals and Scheduling intervals.

In the video on this page, I explain both options with practical examples.

What Is an Update Interval?

The Update Interval defines how often Zabbix should collect a new value for an Item.

For example:

1m

means that Zabbix will normally check the Item every minute.

For many Items, a simple interval like this is enough. But imagine that we want to monitor a service every minute during business hours and only every 10 minutes outside business hours.

This is where Flexible intervals become useful.

Flexible Intervals

A Flexible interval allows us to change the Update Interval during a specific period of time.

For example, we can configure an Item to work like this:

During business hours, check every 1 minute. Outside business hours, check every 10 minutes.

We still have our normal Update Interval, but Flexible intervals allow us to override it during specific time periods.

This is useful when the importance or activity of a service changes throughout the day.

For example, an internal application may be much more important between 8 AM and 5 PM. During those hours, it makes sense to monitor it more frequently.

Scheduling Intervals

Scheduling intervals work a little differently.

Instead of telling Zabbix how often an Item should run, we specify when it should run.

For example, imagine that a backup job runs every day and we only need to check its result once in the morning.

There is no reason to execute that Item every few minutes throughout the entire day. Instead, we can schedule the Item to run at the required time.

Scheduling intervals are useful for scenarios such as:

  • Checking daily backup results

  • Collecting daily reports

  • Monitoring batch jobs

  • Running a check at a specific time

  • Collecting information that changes only once or a few times per day

Flexible vs. Scheduling

The main difference between these two options is the way we define when an Item should be checked.

With Flexible intervals, we change the frequency of checks during a specific period.

For example:

Every 1 minute during business hours and every 10 minutes outside business hours.

With Scheduling intervals, we define specific times when the check should happen.

For example:

Run every day at 07:00.

A simple way to remember the difference is:

Flexible → How often?

Scheduling → When?

Understanding this difference makes it much easier to choose the correct configuration when designing Items in Zabbix.

Why Are Update Intervals Important?

Choosing the right Update Interval is not just about when data is collected. It can also affect the overall design and performance of your monitoring environment.

For example, if a value changes only once per day but we configure Zabbix to check it every minute, we are creating a large number of unnecessary checks.

On the other hand, if we use a very long interval for an important service, Zabbix may detect a problem later than we expect.

A good Update Interval should therefore be selected based on the importance of the metric, how frequently the data changes, and the monitoring requirements.

In the video on this page, I go through Update Intervals and Custom intervals in Zabbix and demonstrate the difference between Flexible intervals and Scheduling intervals with practical examples.