As you all know, Magento 2 uses ElasticSearch.
You will probably realize that Elasticsearch takes a lot of memory... not even joking when I say a lot.
What hardware setup are you using to run ElasticSearch?
Do you have a separate server for it?
What are your Hardware requirements and setup? (CPU/RAM)
You are right that elastic search takes a lot of memory.
For that, CPU and memory size you can adjust according to your search and index traffic and can easily be done if you use the cloud to create the nodes.
As per my opinion, you should give 50% of your RAM as Elasticsearch heap size to get optimal performance.
For example, if you use a host with 256 GB of RAM and the default ratio of 1:32, your host must provide 8192 GB of disk space.
Hope this will help you!
If solved? Click KUDOS and accept as a solution.
Thanks for your answer...256G of RAM is quite a lot but sometime necessary. I only have 8G of ram and will setup my heap to 4G. When I have more visitors/products I'll increase my server size and colocate my own server. Would be interesting to see what people use for their servers.