How to config elasticsearch cluster on one server

I am new to elasticsearch. I have an Elasticsearch index of about 300,000 items. For each of the 60 million records in another table, I need to make a complex query to this ES index.

Right now, it is extremely slow (making 1000 queries would take 200 seconds). I need advice on how to configure my elasticsearch cluster to handle a large volume of queries.

My server:

8 core
8GB ram
SSD Hardware

I want to config elasticsearch to handle 1000 concurrent search requests from ruby. (I want to search 1000 items in parallel).

I have try with the default config

I think by default, elasticesearch can only handle about 10-20 concurrent search request. It use little cpu and ram. Therefore, I think I could improve it.

I could only run 100 threads from ruby to search 1000 items and it takes about 200 seconds. If I increase to 1000 threads from ruby, ES returns timeout error message.

I run a master node with

ES_HEAP_SIZE=2G

indices.fielddata.cache.size: 1g 

threadpool:   
   search:
      type: fixed
      size: 200
      queue_size: 400

shares: 5 

replicas: 1

Running 100 threads from ruby to search 1000 items still takes 200s.

I add 3 new nodes as data nodes on this server.

Running 100 threads from ruby to search 1000 items still takes 200s or more.

I google and read from some posts. People say that create more shards will make search become slow.

How can I improve my search query?

Many thanks!

you're going to want to watch this video:

http://www.elasticsearch.org/webinars/elasticsearch-pre-flight-checklist/

The defaults for ES are great for development but not production. The one thing that you really need to do is give the JVM 50% of the available memory on the server. That video has lots of other great tips.