Elasticsearch

Localhost 9200 Down?

Port 9200 is the JSON interface for Elasticsearch. It doesn't have a UI (use Kibana on 5601 for that).

Go to http://localhost:9200 →
Kill Port 9200
npx kill-port 9200

Verifying Elasticsearch Status

Elasticsearch often crashes silently due to low memory (Java Heap). Check if it's running via curl.

1. The "You Know, for Search" Response

Run this command. If you see JSON, it works!

curl -X GET "localhost:9200/"

2. Out of Memory Fix

If it crashes immediately, increase JVM heap size in your environment variables:

export ES_JAVA_OPTS="-Xms512m -Xmx512m"

Developer Port Reference Guide

Frontend & Web
3000 React / Node / Default 3001 React Secondary
Backend & Infrastructure
5000 Flask / AirPlay 4000 Jekyll / Hexo
Database & Cache
3306 MySQL 5432 PostgreSQL
DevOps & Data Science
8888 Jupyter Notebook 9200 Elasticsearch 9090 Prometheus 15672 RabbitMQ UI 8500 Consul 127.0.0.1 Loopback IP