Built-in tool for backfilling Elasticsearch from Cassandra

[ignaciogonzalezsomoza]

Is your feature request related to a problem? Please describe.
The need to have a complete backup with Cassadra database and Elasticsearch, with capability to restore the entire system in disaster situation

Proposed Solution
(In analysis)

Additional context
Add any other context or screenshots about the feature request here.

[ibarrajo]

Cadence provides a tool to reindex based on an ES snapshot. I'll ask others on the Cadence team what procedures we have in place in order to reindex based on Cassandra or other database.

❯ cadence admin es index -h
NAME:
   cadence admin elasticsearch index - Index docs on ElasticSearch

USAGE:
   cadence admin elasticsearch index [command options] [arguments...]

OPTIONS:
   --url value                     URL of ElasticSearch cluster
   --index value                   ElasticSearch target index
   --input_file value, --if value  Input file of indexer.Message in json format, separated by newline
   --batch_size value, --bs value  Optional batch size of actions for bulk operations (default: 1000)