Recommended heap size

1

Running OH 4.1.1 on RPi4 4GB

There isn’t any specific heap size in Java_Opts, so I guess I’m running a default size?

shell:info shows

JVM
 Java Virtual Machine        OpenJDK Client VM version 17.0.9+9-Raspbian-1deb12u1rpt1
 Version                     17.0.9
 Vendor                      Raspbian
 Pid                         3101
 Uptime                      10 days 6 hours
 Process CPU time            2 days 4 hours
 Process CPU load            0.00
 System CPU load             0.67
 Open file descriptors       250
 Max file descriptors        102,642
 Total compile time          3 minutes
Threads
 Live threads                329
 Daemon threads              169
 Peak                        382
 Total started               641508
Memory
 Current heap size           247,527 kbytes
 Maximum heap size           253,440 kbytes
 Committed heap size         253,440 kbytes
 Pending objects             0
 Garbage collector           Name = 'Copy', Collections = 2695, Time = 40.018 seconds
 Garbage collector           Name = 'MarkSweepCompact', Collections = 76867, Time = 19 hours 21 minutes
Classes
 Current classes loaded      30,013
 Total classes loaded        316,182
 Total classes unloaded      286,169
Operating system
 Name                        Linux version 6.1.0-rpi7-rpi-v8
 Architecture                arm
 Processors                  4
 Total physical memory       3,883,276 kbytes
 Free physical memory        1,503,756 kbytes

253K heap seems rather small given how much memory I have…anyone have recommendations?

2

you can set minimum and maximum heap space via /etc/default/openhab. See this posting [SOLVED] Increasing RAM for Openhab - #6 by stefan.hoehn (for example…)

3

That is 253,000k or aka 253megabyte

If you want some heap guidence try this binding which is found in the Marketplace, and it will give a better break down of your heap usage in the DEBUG level logs and also give you a graph. If you need to change the heap it will give you a WARN message in the logs.