Github user ottobackwards commented on the issue:
https://github.com/apache/metron/pull/863
The minimum required fields, as far as I can see right now are source.type,
original_string and timestamp. Given the use case for this is something that
has skipped the parser topology, we should validate those.
If we think the same can be done for indexing, then we should use the same
classes/technique there.
Again, this is based on the presented use case---
