Are tags kept after pruning

[pkaramol (Pantelis Karamolegkos)]

I am using multiple pipelines, one of which (pipeline_1) adds some tags and sends its data downstream to pipeline_2 via tcp output/input binding.

pipeline_2, as soon as it receives the event, it applies a prune, e.g.:

filter {

  prune {
     whitelist_names => ["^somefieldname$"]
   }
}

Are the tags added by pipeline_1 maintained in pipeline_2 after pruning?

[magnusbaeck (Magnus Bäck)]

I think your prune filter will remove the tags. If you want to keep them you need to include ^tags$ in whitelist_names.

[pkaramol (Pantelis Karamolegkos)]

You are right this is how it works.
prune will remove everything except what is in whitelist_names array and the way to maintain tags (if any) is to e.g.

filter {

  prune {
     whitelist_names => ["^somefieldname$",  "^tags$"]
   }
}