I am looking at the logstash filters in the following parser extension documentation:
1. what does the `array_function` do over here please?
json {
source => "message"
array_function => "split_columns"
}
2. can you please explain what does `"@output" => "event" do? - what does it mean to say bind the udm fields to @output key.
mutate {
merge => {
"@output" => "event"
}
}


