UNASSIGNED ALLOCATION_FAILED

What is the ES version being used? It seems the data is too large to be handled by heap memory available to the Elasticsearch node.
I believe something similar was discussed for 7.x version, you can refer to: Elasticsearch 7.x circuit breaker - data too large - troubleshoot - Stack Overflow

Also, from this disucssion forum earlier posts: CircuitBreakingException - Data too large - Meta Elastic / Elastic Tips and Common Fixes - Discuss the Elastic Stack