Looks like you're trying to index each item individually and hitting a queue limit (200). That generally means you're attempting to index faster than ES can keep up. I'd suggest using bulk api indexing instead as it likely is more efficient.
https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-bulk.html
If you're not able to use that for whatever reason you can increase the thread pool queue in ES (check the docs) but that is likely just postponing the issue.