For several HTTP sensors we get a sporadic response of "Connection closed gracefully" that vanishes by itself, without any interference. However there is no problem on the site, and also additional monitoring system does not show any errors on the same sites. When I try writing the sensor results I get: Stat Connected. Sent 8/11/2015 8:14:31 AM: GET /get_content HTTP/1.1<EOL> Cookie: UserCulture=en-US<EOL> Host: allslots.cdnspstr.com<EOL> Accept: text/html, */*<EOL> Accept-Encoding: identity<EOL> User-Agent: Mozilla/5.0 (compatible; PRTG Network Monitor (www.paessler.com); Windows)<EOL> <EOL> Recv 8/11/2015 8:14:31 AM: HTTP/1.1 200 OK<EOL> Content-Type: text/html<EOL> Content-Length: 0<EOL> Connection: keep-alive<EOL> Server: nginx<EOL> Date: Mon, 10 Aug 2015 21:55:17 GMT<EOL> X-Powered-By: PHP<EOL> Access-Control-Allow-Origin: *<EOL> Access-Control-Allow-Headers: Content-Type, User-Agent, X-Requested-With, If-Modified-Since, Cache-Control, origin<EOL> Vary: Accept-Encoding<EOL> Age: 26354<EOL> <EOL> Stat Disconnected.

But if I open the very same page from the browser on the sensor, I get normal (expected) response with the entire content.

Please assist.

Article Comments

Hello Alexander,

Please update to the latest version of PRTG in order to see if the issue still remains, using the Auto-Update. Alternatively you can download the software from our Paessler Service Center using your registered email and password:

Once you have downloaded the latest version, you can install it directly over the version currently running. The configuration and database will not be affected by installing the newer version over the old and the configuration is automatically backed up before this process.


Aug, 2015 - Permalink

Having the same issue here with "Connection Closed Gracefully" appearing on cloud http sensors. The site is up currently and no issues are being reported from anywhere in our org or externally.

We are running 16.4.27.6720 currently.

Any ideas?


Oct, 2016 - Permalink

Hello,

Please go to the sensor's settings, and Configure the "DEBUG OPTION" "Write sensor result to disk(Filename: Result of Sensor [ID].txt" The log will be written on the probe that monitors that sensor under (C:\ProgramData\Paessler\PRTG Network Monitor\Logs (Sensors)) and send us the result.


Oct, 2016 - Permalink