Raspi 2b with OH4.01 - performance

I face a dramatic reduction of performance (factor 5-20) with migration from oh3.4 to oh4.0 on my RaspberryPI 2B.
latest DietPi: Debian GNU/Linux 11 (bullseye)
OpenJDK Runtime Environment Zulu17.42+19-CA (build 17.0.7+7)

One core is very often at 100% full load.
Many communication errors in this case with web browser.
RAM is used only by 60%,

Idle situation:

Following Blockly took less then 3 seconds on OH3.4

Now, with oh4.0 it is running more then 90sec!

Used addons: mqtt, java-automation, jdbc maria, http, jsonpath, androidtv,
Logfile is proper - no warnings , no errors.
About 100 items.

Any hint?
Has somebody made similar epxerience?

I’m wondering.
I carefully read all performance forum topics but I basically do not hear any so heavy problems.


It is well known that openHAB 4 and Java 17 require more processing power and memory, and I’ve also read a few reports about Threads with permanent 100% load.

Blockly now uses JS Scripting (GraalJS) which includes the helper library. The injection of that library (which has a pretty large codebase) is what takes so long, but we also had a bug on our cached injection with openHAB 4.0.0 and 4.0.1, the fix will be released with 4.0.2.

Generally, you should consider buying a new Pi, because 2b is pretty old now and the Pi 4 is much more powerful.