Yes logstash start is so slow I use reload automatic parameter see below
this will start logstash and you can update any parameter it will reload it automatically
in case there is an err it keeps printing the err message on default output (terminal) as soon as you fix it
bin/logstash -f configfile.conf --config.reload.automatic
my best practice working with logstash is to run it this way w automatic reload having output to screen
and I randomly put line by line to the tail of this file and check the desired output
I was curious of are others best practices to dev with logstash?