Are we looking at different threads of the same JVM process or are you actually running dozens of Logstash processes?
running 4 logstash processes.
As I've mentioned, I got 4 logstash conf files that looks like the one I uploaded.
Then on the server, I run following command to run them in the background.
nohup bin/logstash -f logstash1.conf &
nohup bin/logstash -f logstash2.conf &
nohup bin/logstash -f logstash3.conf &
nohup bin/logstash -f logstash4.conf &
But I don't think the number of logstash file matters a lot.
I checked heap memory while running only one logstash but got the same error, 'HeapDumpOnOutOfMemory'.
I'll be looking forward to hearing from you.
Best
Gee
------UPDATED------
If you're talking about JVM, yes each logstash is producong approximately 10 threads, thus provoking 'HeapDumpOnOutOfMemoryError'.