Logstash remove field

Elastic Stack Logstash
1

Hi I am new to ELK. I am thinking what is the best way to remove field.

  1. Just use mutate filter and remove field
  2. First set field to nil and then use mutate filter and remove

What is the best way to remove the field. And I want to free the space on my heap quickly.

2

Just use mutate remove_field. As this will remove it before ingest it.

3

I want to know how it helps for garbage collector to save space on heap

4

Can you explain, in detail, why you care about that? What do your current GC stats look like? What does the logstash pipeline configuration look like?