Does your dashboard or graph take a long time to load? When you look at larger time period, does it take a longer time to load, or even completely fail to load?
This probably means that you submit many different tags for the metrics of your graph.
For a given metric, and for each unique combination of tags with which you send data to Datadog, we create a new record on our backend to store things separately. We do this so that we are able to exactly identify the data you asked for when you query a metric for any specific tag combination.
With a large number of unique tag combinations, it will take a longer time to query and aggregate data on our end. This causes a delay in populating your graph with data. Within a wider time-window, it's likely that there will be even more unique tag combinations, resulting in a longer delay before you see metrics. You may even see no visualization at all when the delay hits the time out.
You may find information and examples about unique tag combinations in this article:
As a consequence, we encourage you to tag your metrics with fewer than 1000 tags for querying purposes. You can review the number of tags for any specific metric on your Metric Summary page.
Please also note that the number of custom metrics (where a custom metric refers to a single, unique combination of a metric name, host, and any tags) may count towards your billing. We usually offer a soft limit of 100 custom metrics * # hosts monitored via Datadog.
If you plan on continuing to submit more custom metrics than the billing limit in the future, or if you have any questions, please reach out to email@example.com