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Inconsistent report results

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I have 6 HTTP sensors in one device group. I made a report to obtain an automated status update each morning. After noticing some inconsistency with the sensors (showing no data when the sensor has always been up & hadn’t gone down in over 5 days), I made a second report thinking I had simply set up something wrong on the first. I set the second report up, but after setting the interval the report was pretty much the same as the first. None the less, I let it run the next morning and some of the sensors that were showing ‘no data’ on one report, would be 100% Up and good on the second report. I monitored these inconsistent results continue on for the last 10 days or so. Why is this happening?? Both reports ran at 5AM this morning and one has no data for all of the sensors? The second shows 6 out of 6 sensors are 100% up and running.

http-sensor inconsistent reports

Created on Aug 30, 2018 12:11:19 PM



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Accepted Answer

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Sure, you've sent us also the reports as PDF by email and after revisiting those, this was my answer then:
The issue is most likely with how the report is configured. Both reports are configured to look at a period in the future, more or less. At the bottom of the page on each report you can see when the report was started. One report was started on 8/28/2018 5:00:28 AM, while on top of the page we can see it should cover data from 8/28/2018 5:00:00 AM - 8/29/2018 5:00:00 AM 24 / 7, so basically it looks into the present and future. Most likely there was no sensor result available right there at 5:00 AM, therefor this report contains no data for the configured period it should cover.

The other report was started around one minute later at 8/28/2018 5:01:29 AM, also covering the same period and at this point in time there was a sensor result present. You can also see it when looking closely that the data is based on exactly one scan (1 Good, 0 Failed).

I would recommend to set the report generation a little bit later, because when starting at 5:00 in the morning, covering a period that also starts at 5:00 in the morning, might end up then having no sensor results to present at this very point in time.

Kind regards,

Erhard

Created on Aug 30, 2018 2:17:56 PM by  Erhard Mikulik [Paessler Support]

Last change on Aug 30, 2018 2:18:08 PM by  Erhard Mikulik [Paessler Support]



5 Replies

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Hello there,

You've sent us the same question by email recently and I've replied to it. Did you receive that email?

Kind regards,

Erhard

Created on Aug 30, 2018 12:39:25 PM by  Erhard Mikulik [Paessler Support]



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Hi, I never received a response. I just checked my inbox again. Can you paste the answer here or resend the response?

Created on Aug 30, 2018 1:03:48 PM



Accepted Answer

Votes:

0

Sure, you've sent us also the reports as PDF by email and after revisiting those, this was my answer then:
The issue is most likely with how the report is configured. Both reports are configured to look at a period in the future, more or less. At the bottom of the page on each report you can see when the report was started. One report was started on 8/28/2018 5:00:28 AM, while on top of the page we can see it should cover data from 8/28/2018 5:00:00 AM - 8/29/2018 5:00:00 AM 24 / 7, so basically it looks into the present and future. Most likely there was no sensor result available right there at 5:00 AM, therefor this report contains no data for the configured period it should cover.

The other report was started around one minute later at 8/28/2018 5:01:29 AM, also covering the same period and at this point in time there was a sensor result present. You can also see it when looking closely that the data is based on exactly one scan (1 Good, 0 Failed).

I would recommend to set the report generation a little bit later, because when starting at 5:00 in the morning, covering a period that also starts at 5:00 in the morning, might end up then having no sensor results to present at this very point in time.

Kind regards,

Erhard

Created on Aug 30, 2018 2:17:56 PM by  Erhard Mikulik [Paessler Support]

Last change on Aug 30, 2018 2:18:08 PM by  Erhard Mikulik [Paessler Support]



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That seemed to do the trick! Thank you so very much.

I am curious, when running historical reports, at time there are a couple minutes of 'unknown' or gray shades of color, could you give me an idea of what that means? was there a brief period where the HTTP sensor did not have any connectivity to website?

Created on Sep 5, 2018 1:54:00 PM



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Check the regarding sensor's "Log" tab, there you should also events when the sensor was gray, meaning status "Unknown". This is basically a pretty "unwanted" state, it does not mean necessarily that the sensor was not able to reach the site, but something caused the sensor to get no result at all.

Either a sensor should be green or it should go to error if something goes wrong with the query, but "unknown" means it did get no response at all to work with.

This state can occur temporarily in certain cases like when PRTG is starting up and it takes a little bit until the first responses from sensor queries start coming in, but it should not stay in that state for longer periods. If that is the case, open up another support case about that, so we can look at this in more detail.

Kind regards,

Erhard

Created on Sep 6, 2018 4:56:46 AM by  Erhard Mikulik [Paessler Support]




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