In the alert panel, the array size of the query result is not match with the database

[yangdaren]

hi, there

I am currently using the Grafana V8.0 and influxDB as the data source.
I add a graph and try to add an alert rule for this graph.
the data in database is received from a IOT device every 5 second, just like this:

here is the alert rule I added for the graph:

from my understanding, the rule means:
the rule will run every 1 minute, to get the data from now-1m to now, so theoretically， the query result should contain 12 points each time, because one minute should contain 12 points as shown in the first picture, but unluckily, after I click the test rule button, each time the number of the query result is different, sometimes it contains 2 points, sometimes it contains 6 points, as shown in the 2nd floor:

I am not sure it is due to the network quality or the configuration is wrong, or my understanding is not correct? could anyone give me a hand for this issue?
thanks in advance

[yangdaren]

here is the query response for reference

[grant2]

Try changing the For field from 0m to 4s and see what results come up.

[yangdaren]

unluckily, the query result is the same with previous
sometimes, the array size is 2, sometimes is 6, from my point of view, the array size of the query result should be 12 each time, am I right?

[grant2]

Let’s try this…

Change the query (A,1m,now) to query (A, 5s, now) and see what happens.

[yangdaren]

according to the document from Grafana, the minimum of the query time is 10s
so I changed the query to query(A,10s,now),
the result is that: empty
which means that the query result array is empty, no data response
I tried several times, the results are all empty
it is very interesting

[grant2]

Does this change your results? change max() to last()

[yangdaren]

unluckily, it doesn’t work either