I have an interesting one. I have a working v7.7 logstash config (on RHEL 7.x) which has suddenly stopped ingesting files. I am using the file input plugin in read mode to ingest single-use CSV files (each about 2 lines - a header and a data line).
I suspect this has to do with the recently increased number in the numbers being received. (from 6 digits to 8-9 digit numbers). This fixes itself for a bit for a short period and jams again.
I have looked into the usual places, without luck. Any suggestions on what I should be looking into?