Thank you Nicolas,
I just played around a bit more and it looks like my final solution will be the following:
(The following applies to each filebeat node, but thats what deployment piplines are for, right?)
- copy&unzip the file to reimport
- deploy a custom filebeat.yml (with close_eof)
- run filebeat.sh on command line with -once parameter and the custom filebeat.yml
This way we achieve the following:
- keep the existing logstash configuration
- performance is ok and no issues with high load on filebeat nodes
- logstash persistence buffer can be used