ELK Guide
ELK(Elastic, Logstash & Kibana)
- Open source products by Elastic company
- Allows to take data from any source, in any format & to search, analyze & visualize data in realtime
- Centralized logging for any number of servers & applications
ELK Stack Architecture
- Logs : Server/application logs
- Logstash : Shipping, processing and storing logs. Collects logs, events data. Parses & transforms data
- Elastic/Elastic Search : Stores logs/transformed data from Logstash(Store, Search & Indexing). NoSQL DB based on lucene search engine & build on Restful APIs
- Kibana : Web interface visualization tool hosted through Nginx or Apache. Uses Elastic search DB to explore, visualize & share
- Beats : Data collection. Hence, ELK became ELK Stack
- Messaging Queue can be used for large data logs and maintaining resiliency
Working
- Logs -> Beats -> Message Queue Buffering -> Logstash -> Elastic Search -> Kibana
Alternatives
- Splunk : Commercial tool providing on-prem & cloud solution. Quite accurate and fast
ELK Use Cases
- Netflix's Security Log
- LinkedIn's performance & security
- Medium's production issues & DynamoDB Hotstop tracking
Best Practices
- Logs written to single ELK instance
Installation
ELK
Type 1 : Local Download- Start Elastic search server(C:\elasticsearch\bin\elasticsearch.bat) & check if running in http://localhost:9200/
- Start Kibana(C:\kibana\bin\kibana.bat) & check if running in http://localhost:5601/
- Start Logstash(C:\logstash\bin) and type
cmd binlogstash -e 'input { stdin { } } output { stdout {} }'
Type 2 : Running ELK in Docker
- In Docker Quickstart Termainal, run below commands to download & run ELK
- Elastic search
docker pull docker.elastic.co/elasticsearch/elasticsearch:7.9.3
- Start single node cluster
docker run -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" docker.elastic.co/elasticsearch/elasticsearch:7.9.3