In non-AWS-managed ElasticSearch, you can increase the value for http.max_content_length configuration when you send data to the nodes to be indexed in batches to a value larger than the default 100MB.
This would be done in the elasticsearch.yml file.
In Amazon OpenSearch, you don't seem to have the option to modify the opensearch.yml(?) so how can you make a similar change when you encounter this issue?
Is it possible to increase the default 100MB limitation in Amazon OpenSearch?
AWS sets a hard limit on the maximum size of HTTP request payloads dependent on the instance type used.
Currently, this is either 10 MiB or 100 MiB & cannot be manually changed.
AWS does not provide access to any .yml configs since the selling point of Amazon OpenSearch/ES is that it is managed for you & handles many configuration settings behind the scene.