As a developer, was using it for quite a lot of time for different projects and would say it is almost impossible to find an alternative for this product due to the fact it is the best product in the segment.

and look for log files and then find the issue. ELK sovles this problem efficiently.During troubleshooting, it is biggest pain to open servers

Free! API driven Scalable multi-node architecture. Easy to understand JSON Tight integration with logstash and the rest of their stack

I've been using Elasticsearch since early days, with very different things in mind. I started with simple text search - with some additional tweaks, stemming and other cool features it helped us drive enormous traffic to our website. I can't imaging pulling it off so easily with any other tool. Every day I use it for web server log analytics. Search and great visualizations make it an absolute essential in work my toolset. We also run a lot of algorithm analytics on top of our Elasticsearch cluster. If you're looking for managed options check AWS Elasticsearch Service, or the recently introduced Elastic Cloud.

Elastic Search is easy to install Easy to use as there are loads of documentations present online Easy to scale up when the need arises Uses REST FULL API which is light weight.