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No historical debug logs retained following August update



Over the weekend we updated from to the August update Since then I notice the Result Handling debug logs (eg those in C:\ProgramData\Paessler\PRTG Network Monitor\Logs\sensors) now only store the last result, with none of the older results remaining for comparison.

Is there a reason this has changed, as it makes a LOT harder to troubleshoot issues when you're reliant on catching it and grabbing the log data when a failure event happens, rather than being able to find it later?

In it definitely behaved differently, as did Back in May I was using those logs, and found the rotation was such that a sensor testing every minute only had data for about 70 minutes, while one that tested every 5 minutes had just under 6 hours, with the logs clocking in at between 27KB and 45KB. So not a massive amount of log data.

At the time I asked if it was possible to increase the amount of log data stored (https://kb.paessler.com/en/topic/90615-adjusting-result-handling-storage-log-file-rotation-filesize-entries) and was told it wasn't possible, and now it seems PRTG has gone one step further so no historical data is stored at all.

debug log prtg result-handling

Created on Sep 13, 2022 9:49:55 AM

2 Replies




most sensors never had a rotating logs in the first place. We plan to introduce it for more sensors in future versions.

Or is your question about sensor data which can be graphed via the tab "Historic Data"? There was no change either though.

Or is the question about "core.log", "probe.log" and similar files? These should rotate every 64 MiB.

Created on Sep 13, 2022 1:26:32 PM by  Arne Seifert [Paessler Support]



In this case the sensors definitely did. I've got a load of different SMTP / POP3 round trip / FTP sensors that all have SSL/TLS enabled, and would periodically give errors in PRTG, so to get to the bottom what caused it, and see what was happening prior to and when the error first happens, I set those specific sensors to "Store result".

Every single one of them had multiple hours worth of data stored, and automatically rotated / removed the oldest data from the logs over time, so the "Result of Sensor nnnn.txt" log files never got more than about 50KB in size. Now following the update those same sensor logs have a single entry and are 1KB. Those logs contain the detailed transaction information relating to the sensor in question, for instance the FTP handshake messages back and forth and any errors that come up, the back and forth with the SMTP and POP3 connections showing the detailed communication between PRTG and the mail server etc.

Fortunately since the previous rotation meant in some cases the old log data would be gone after just 6 hours I wrote a script to grab a copy of the logs every hour, which now means I can still see how they were appearing this time last week before the update.

Created on Sep 13, 2022 4:04:06 PM

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