ELK (Elasticsearch / Logstash / Kibana) is a popular stack for log aggregation and viewing.
The Logstash support in Swarm outputs stack traces in a format that Kibana does not understand.
Proposed is to output stack traces as a formatted string/text block rather than a JSON array of json objects of exception stack frames.
Additionally, I think "caused by" exceptions are currently lost in the current implementation as well, making stack traces much less useful for determining root cause.
The actual exception class (e.g. java.lang.NullPointerException) is also absent from the log
Kibana also issues a warning that JSON objects inside text fields are not very well supported