OpenJDK and Zulu in openHABian

Beside that problem my clients are also reacting strange (display kind of freezes). I forgot to mention that I installed OpenJDK. Did you also migrate to OpenJDK?

Is it really OpenJDK or Zulu 11 ?
If it is not Zulu 11, you are using a non recommended Java version with known issues.

1 Like

Ok. I probably misinterpreted this:

and the changelog of openhabian:

Major Java provider switch ## December 15, 2021
We have switched to supporting only the OpenJDK package provided by default from
the APT repo for all new installations of openHABian. Existing installations
will be unaffected, however you will no longer receive updates to your current
Java install until you install Java from the new provider which you can do by
running menu option 45.

That’s why I moved to OpenJDK 11

Was not aware of this options as I don‘t use openHABian.

Unfortunately it is not possible to revert back to Zulu 11 by menu option. Going back manually now and see if the problem persists.

IMO this is also a bad decision. Zulu Java works perfectly and on many different OS and architectures.

To be honest, I was not aware of such changes in openHABian and our prerequisites still recommend Zulu Java. Need to check……

1 Like

The release notes say OpenJDK for new installations. I assume that a few more users are irritated by that deprecated flag

Does anybody know how to manually revert back to Zulu JDK 11?
I assume it is not done just by simply installing this package:
zulu11.52.13-ca-jdk11.0.13-linux_aarch32hf.tar.gz (for RPi4)
I better ask the experts here before :slight_smile:

I just checked that even the installation instructions for manual installation on Raspberry Pi recommend Zulu Java (as all other platforms do).

See github: Change Java providers and add support for Java 17 by ecdye · Pull Request #1632 · openhab/openhabian · GitHub

My client freezes once every hour.
So I better revert back to Zulu.
Does anybody know if it is just a matter of installing the package or do I need to do some manual changes in config files?
Just for completeness: reverting back with openhabian config menu is not possible.

well, haha, somehow Markus saw that coming up

Please elaborate. What’s your client and what do you mean by ‘freezes’.
Do other clients (other browser, app, automations) keep working meanwhile ?

thanks for getting back on this.
I’d suggest that I revert back to Zulu JDK first and see if the problem persists. In that case it makes sense to elaborate further.
However, I am uncertain what needs to be done to revert back. Is it just a matter of installing Zulu11-32 package or do I need to do some more actions like changing config files?

Fixed, use openhabian-config to revert and it should work now.

1 Like

Hi Ethan, thank you very much for your quick fix.
I’ll post latest tomorrow if the problems I had were related to OpenJDK.

I reverted back tu Zulu JDK thanks to your quick openhabian update.
Problem still persists.
Here are more details:

I have a wall mounted tablet running MainUI which is constantly connected to OH3. After a couple of hours the connection to OH server is lost.

  • Colors, Icons and Labels do not represent the actual state anymore
  • If I click on a cell which his configured with actionCommandAlt: it only sends one of the two commands even when pressing multiple times (as can be seen in the log)
  • If I launch one of my status widgets which just shows current states of selected items, none of the states can be retrieved from the server
  • after refreshing the browser everything works fine again.

problem occurred after updating from OH3.2M5 to OH3.2

Server details:

  • OH3 Version 3.2
  • Zulu Java
  • Kernel version Linux 5.10.63-v7l+ (latest openhabian)

Client details:

  • iPad mini 4 iOS 15.2, Safari browser
  • MainUI startet from home screen (Progressive Web App)
  • everything which might interfere from a networking point of view ist deactivated (e.g. private MAC address)

How can I check the IP and http connection on operating system level from my OH server to get more information?
Could I provide you with more details?

So it’s unlikely to be OpenJDK related. Sorry to tell but that’s my primary interest here and I wouldn’t know how to debug your issue.
I’d start ramping up debugging. There’s probably a setting for jetty (the web server) that should get you more information if your issue is really tcp or http sessions being dropped but I don’t know it so you have to search the forum and net yourself please.

(I suggest you open a new thread)

Hi, @Oliver2.

I’ve had a similar problem with my iPhone 6s. I always thought it happened because my phone is always running out of free space. Very frequently I need to restart it for it to release some space, but now that I read this thread I started suspecting of the progressive web app.
I also added a PWA and many times it gets temporarily frozen when I switch to other apps or the screen is turned off. I don’t leave it on all the time and don’t use it only to access OpenHAB (MainUI).
I think it happened even when I was running OpenHAB 2.5 on a RPi 3B (OpenHABian and the supported JDK). I updated OpenHAB to 3.0 and 3.1 on the same RPi and kept having the same problem.
I replaced the RPi for an RPi 4B (CentOS 64-bits + OpenJDK 11 64-bits) and keep having the same problem.

Going back to the PWA, sometimes when I reopen it, I have to wait a little bit for it to become responsive and load another page for it to work again. Sometimes it doesn’t become responsive and I have to close the app and open it again. I never close apps unless they behave strange.
When I load the MainUI directly on Safari I don’t have those problems.

I did some more testing and can confirm this.
I opened a new thread for this.
see here