Filebeat filestream configs that pass test config but still fail
A Filebeat config can print Config OK and still exit on start, ship your multiline settings as event data, or send a whole log file to your stack twice. We found most of these while testing the Filebeat configs on our integration pages, then rebuilt each mistake, plus the migration traps around them, on Filebeat 8.19.23 and 9.5.5 to see exactly what happens.