Is there a document that list the various fields of the elasticsearch log?

[pshroads]

Given a snippet of a log file like this I'm wondering if there is documentation for all the various possible values for the second and third columns (eg. INFO and plugins)

[2015-12-30 18:33:14,176][INFO ][plugins] [myserver.mycompany.com] loaded [analysis-icu, marvel, action-updatebyquery], sites [marvel]
[2015-12-30 18:33:15,861][INFO ][node] [myserver.mycompany.com] initialized
[2015-12-30 18:33:15,861][INFO ][node] [myserver.mycompany.com] starting ...
[2015-12-30 18:33:16,024][INFO ][transport] [myserver.mycompany.com] bound_address {inet[/170.20.52.10:9300]}, publish_address {inet[/170.20.52.10:9300]}
[2015-12-30 18:33:16,031][INFO ][discovery] [myserver.mycompany.com] p2-contact-data-new/bw7qpYdCTLidt4J5dHRMbg
[2015-12-30 18:33:19,072][INFO ][cluster.service] [myserver.mycompany.com] new_master [myserver.mycompany.com][bw7qpYdCTLidt4J5dHRMbg][myserver.mycompany.com][inet[/170.20.52.10:9300]]{max_local_storage_nodes=1}, reason: zen-disco-join (elected_as_master)
[2015-12-30 18:33:19,105][INFO ][http] [myserver.mycompany.com] bound_address {inet[/170.20.52.10:9200]}, publish_address {inet[/170.20.52.10:9200]}
[2015-12-30 18:33:19,107][INFO ][gateway] [myserver.mycompany.com] recovered [0] indices into cluster_state
[2015-12-30 18:33:26,270][INFO ][cluster.metadata] [myserver.mycompany.com] [.marvel-2015.12.30] creating index, cause [auto(bulk api)], templates [marvel], shards [1]/[1], mappings [default, shard_event, index_event, index_stats, node_event, routing_event, cluster_event, cluster_state, cluster_stats, node_stats, indices_stats]
[2015-12-30 18:33:26,538][INFO ][cluster.metadata] [myserver.mycompany.com] [.marvel-2015.12.30] update_mapping [node_stats] (dynamic)

[nik9000 (Nik Everett)]

[INFO ] and its ilk are log4j2 levels.

[plugins], [node], etc are all package names of Elasticsearch's internals. You could get a list from the source but it wouldn't be stable.