Warning in log - "rebuilding Selected Selection Key Set Selector"

Setup, Configuration and Use Runtime
1

Hi OH community,

Not really sure in which category to post that question, giving it a try here.
In my OH2 log I am seeing a warning like “Rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector” every 1-15 minutes. It looks like this:

2019-11-09 23:06:25.686 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@16176ee.
2019-11-09 23:11:30.652 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@4b825f.
2019-11-09 23:16:30.283 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@1d3c510.
2019-11-09 23:17:22.319 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@18d9d3.
2019-11-09 23:23:42.406 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@105a658.
2019-11-09 23:24:53.703 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@155e4b3.
2019-11-09 23:27:24.314 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@15677c8.
2019-11-09 23:35:48.591 [WARN ] [io.netty.channel.nio.NioEventLoop ] - Selector.select() returned prematurely 512 times in a row; rebuilding Selector io.netty.channel.nio.SelectedSelectionKeySetSelector@11af7ef.

Is that anything I should worry about? How could I dig deeper into what is causing that?

Currently I am using the following bindings:

  • Astro
  • IpCamera
  • Network
  • SynologySurveillanceStation

Would I be supposed to switch debug mode on for each of them to see where it comes from?

Cheers!

2

From searching, I would guess the problem is the IP Camera binding. You could be running an ancient version of OpenHAB.

Since you provide no information about your system that is probably the best information you can get here.

3

Thanks for your answer and apologizing for the missing details.

I am using openHAB 2.4.0-1 (Release Build) as openhabian system on a Raspberry Pi.
Release = Raspbian GNU/Linux 10 (buster)
Kernel = Linux 4.19.75-v7l+
Platform = Raspberry Pi 4 Model B Rev 1.1

Thanks for the hint, I will now work on debugging ipcamera binding first and check with the author.

4

You will most likely be asked to update OpenHAB or at least that binding to the latest rest release 2.5 Milestone 4.
2.4 is considered quite old now. The 2.5 release was delayed and is now expected at the end of this year.