Sorry if this has been covered previously but I wasn't able to find an existing question covering this.
We have an SQL Query-based Sensor looking at a logging table for an in-house application. We have configured this sensor so that if a particular error message appears in the log table to raise an Alert (e.g. Sensor goes 'down'). The query uses the date-time so that it is only looking at the last hours worth of log entries.
My question is, how do I set PRTG so that when this Sensor goes 'down' it doesn't automatically come 'Up' at the end of the hour? Ideally what I am trying to achieve is have the Sensor go 'Down', generate an Alert and then have one of our technicians go and investigate that error before manually clearing it and allowing the Sensor to come 'Up'.
This is especially important if the error condition occurs during the night - as it currently is, the sensor comes up and therefore the alert is cleared before our technicians come to work in the morning so they don't even see that it was down. We tried using email alerting, but as we have so many sensors (other than this one), the emails get lost - especially when there is an 'up' email for that same sensor, it is easy to delete both emails thinking the problem was only intermittant and the problem has self-resolved. The other thing we tried was removing the 1-hour time period, but this means that if there is EVER an error entry, the sensor stays 'down' - although this does allow us to acknowledge the sensor and investigate, when we resolve the issue, the sensor still shows as 'down' (we definitely do not want to wipe that error entry from the log table).