Data gets lost when either logstash/elasticsearch server is down.. and data gets picked up when one of the both servers are restarted again.. Is there any way to recover/stop the data to be lost. Or search anything else for this issue ?
Well, Kibana has really nothing to do with this. It doesn't store any data, it just queries the data from Elasticsearch. If you're losing ingest data, I'd suggest using Kafka as a layer in between your shippers and Elasticsearch, to store the data temporarily while your ES server is down.