Explain ES indexing is done via a listener
- Detecting failed index operations (log, dead letter)
- on the fly solution: dead-letter (link)
- Triggering all sort of re-indexing
- Re-trying a failed re-indexing
- Adapting James index parameters using ES APIs without downtime. (shard count/replication factor/analyser language)
DOD: try the procedure locally, document it.