SLOs troubleshooting
⛭ SLO not reporting data
This message appears when no data is collected from an SLO objective during a selected time window.
You may encounter situations where the tiles display "No data" while the charts have information. It is also possible when both the tiles and charts are empty.
The charts are designed to provide a broad picture of the objective's status over the time window, while the tiles focus on the most recent data. This helps in assessing whether the objective is collecting data with sufficient granularity.
Here's a breakdown of the time ranges used:
- Tiles: data from the last seven days of the selected time window
- Charts: data from the entire time window chosen
For a more comprehensive understanding, let's consider the following example scenarios with different time windows. The examples assume that now is July 10, 2024, at 12:00.
| Time window | The tiles time range | The charts time range |
|---|---|---|
| > 7-day rolling or calendar-aligned started more than seven days ago, ends in the future | July 4 12:00 – July 10 12:00 | The entire time window (elapsed) |
| Past rolling or calendar-aligned May 10 12:00–June 10 12:00 | July 4 12:00 – June 10 12:00 | The entire time window |
| < 7-day rolling or current calendar-aligned started less than seven days ago | The entire time window (elapsed) | The entire time window (elapsed) |
The following can postpone data income:
| Cause | How to diagnose | Solution |
|---|---|---|
| Query parameters | Both tiles and charts are empty |
|
| Data source | A mismatch between tiles and charts and no data in both | Refer to the data source troubleshooting guide. |
| Query | A mismatch between tiles and charts and no data in both |
|
| Replay | A mismatch between tiles and charts and no data in both | Data appears upon Replay completion. If no, check the data source or query for any issues. |
⛭ The reliability tile color mismatches its value
When you change the reliability target for your SLO, Nobl9 recalculates the values for the error budget remaining and reliability after the following data income upon the target change.
Until the next data income, the following happens:
- The reliability target displays the actual (newly changed) value.
- The color of the Reliability tile depends on the target you set.
- The Error budget remaining and Reliability tiles display values based on the data already collected.
So, when you increase the reliability target, the Reliability tile can become red while its value is high and the error budget remaining is sufficient. Or when you decrease the target, the Reliability tile can turn green even with a small value and too little error budget remaining.
This will change once Nobl9 collects new data. However, it's saved in the SLO history, so you will still see it when rewinding the time window to the period of target modification unless you change the target again or replay1 the SLO.
1The maximum period for historical data retrieval limit per data source is applied.
⛭ My SLO fails to receive data
First, try to restart your agent. If this doesn’t work, contact Nobl9 support.
⛭ SLO shows a negative error budget burn rate
If your SLO shows a negative error budget, check if your query is correct or contact Nobl9 Support.
⛭ Error budget is more than 100%
If your error budget is above 100%, check if your query is correct or contact Nobl9 Support.
⛭ An SLI chart shows different values for the same time at different time scales
This can happen when the sum aggregation is set for a non-incremental ratio SLI.
For this SLI type, Nobl9 adds every next data point to the previous point, and the SLI chart displays the sum of these time series.
Zooming in the chart narrows down the timespan for the displayed data, so it covers fewer data, reducing the values you see.
In contrast, when you zoom the chart out, the timespan widens (and captures more data), so the displayed values grow.
Learn more about:
- SLO calculations
- SLI aggregations
- Discrepancy between Nobl9 SLI charts and the values from a data source
- SLO inputs and outputs
⛭ Reliability increases after a bad event with a high burn rate
This behavior is natural for rolling time windows.
As the time window moves forward, data points expire and appear on a first-in, first-out basis. Once the time
window advances enough
for the bad event to fall out and be replaced with good ones, the reliability improves.
An old error may
expire exactly as soon as a new error arrives. In this case, reliability change depends on the weight of these two errors:
-
→ The old error = the new error: reliability doesn't change
-
↘ The old error < the new error: reliability decreases
-
↗ The old error > the new error: reliability increases
Another scenario explaining why this happens is an SLO with the Occurrences budgeting method with any time window type. This method considers the total number of data points arrived during the period. The more data points come, the less a single data point weighs. Therefore, the good points can eventually outweigh the bad ones even when some bad points are still being registered. As a result, reliability improves.
⛭ Composite SLO reports no data
The following reasons can cause a composite reports no data:
- Your composite doesn't include children.
- All children in your composite SLO report no data:
- Issues with their data sources.
- Issues with child SLOs configuration. Try checking their queries.
- Component SLOs are being replayed at the moment.
- Data source agents fail to exchange data with the data sources
Also learn how Nobl9 handles data backlog. - Components of the composite are entering the exclusion period, according to the budget adjustment configured. So they stop reporting data for this period.
