It looks like Elasticsearch is currently missing support for concurrent searching and that this is a major prospective optimization to reduce latency.

Digression: this is not the topic at hand but I personally consider the fork OpenSearch to be an historical tragedy of duplication of work and a segregation of improvements. What would be even more anti-utilitarist would be to blindly *ignore* each other advances towards making better search.

Lucene concurrent search APIs are probably among the most important feature/optimization currently not leveraged by Elasticsearch.
The fork OpenSearch has a [pull request](https://github.com/opensearch-project/OpenSearch/pull/1500) implementing support for it.

See also the [corresponding issue](https://github.com/opensearch-project/OpenSearch/issues/1286) 

I believe it would be great for end users if you could take inspiration from the PR and work on this feature.

Great blog about the Lucene feature:
https://blog.mikemccandless.com/2019/10/concurrent-query-execution-in-apache.html?m=1
See also those performance results:
https://engineeringblog.yelp.com/2021/09/nrtsearch-yelps-fast-scalable-and-cost-effective-search-engine.html
server/src/main/java/org/elasticsearch/search/SearchService.java
}
            @Override
            public void onFailure(Exception exc) {
                processFailure(context, exc);
                Releasables.close(releasable);
                listener.onFailure(exc);
            }
        };
    }
    private static boolean isScrollContext(ReaderContext context) {
        return context instanceof LegacyReaderContext && context.singleSession() == false;
    }
    private void processFailure(ReaderContext context, Exception exc) {
        if (context.singleSession() || isScrollContext(context)) {
            
            freeReaderContext(context.id());
        }
        try {
            if (Lucene.isCorruptionException(exc)) {
                context.indexShard().failShard("search execution corruption failure", exc);
            }
        } catch (Exception inner) {
            inner.addSuppressed(exc);
            logger.warn("failed to process shard failure to (potentially) send back shard failure on corruption", inner);
        }
    }
    private void parseSource(DefaultSearchContext context, SearchSourceBuilder source, boolean includeAggregations) throws IOException {
        
        if (source == null) {
            return;