ElasticSearch Unable to revive connection: http://elasticsearch:9200/ - docker

Question

I tried to run ELK on Centos 8 with docker-compose :
here my docker-compose.yml
version: '3.1'
services:
elasticsearch:
image: docker.elastic.co/elasticsearch/elasticsearch:6.2.4
container_name: elasticsearch
hostname: elasticsearch
ports:
- "9200:9200"
expose:
- "9200"
volumes:
- elasticsearch-data:/usr/share/elasticsearch/data
networks:
- docker-network
kibana:
image: docker.elastic.co/kibana/kibana:6.2.4
container_name: kibana
ports:
- "5601:5601"
expose:
- "5601"
environment:
- SERVER_NAME=kibana.localhost
- ELASTICSEARCH_URL=http://elasticsearch:9200
- ELASTICSEARCH_USERNAME=elastic
- ELASTICSEARCH_HOST=elasticsearch
- ELASTICSEARCH_PORT=9200
- ELASTIC_PWD=changeme
- KIBANA_PWD=changeme
depends_on:
- elasticsearch
networks:
- docker-network
networks:
docker-network:
driver: bridge
volumes:
elasticsearch-data:
but i'm facing with this error :
{"type":"log","#timestamp":"2020-03-03T22:53:19Z","tags":["warning","elasticsearch","admin"],"pid":1,"message":"Unable
to revive connection: http://elasticsearch:9200/"}
while i checked:
elasticsearch is running fine.
docker exec kibana ping elasticsearch work fine.
both kibana and elasticsearch are on same network as you can see in docker-compose.yml
i checked docker exec kibana curl http://elasticsearch:9200 and result is :
Failed connect to elasticsearch:9200; No route to host
I also check other similar problems and their solution but none of them worked.

Answer 1

If you are running ElasticSearch inside Docker, then you may need to check if you have allocated sufficient memory limits to Docker. This can cause ElasticSearch to slowdown and even crash.
By default Docker Desktop is set to allow 2Gb of RAM per Docker, but in my own project I found that 4Gb prevented crashing, but 5Gb produced an additional performance speedup. Your mileage may vary depending on the amount of data you are ingesting.
Docker Desktop memory settings can be set via:
Docker Desktop -> Preferences -> Resources -> Memory
To inspect memory usage within the Docker container
DOCKER_ID=`docker ps | tail -n1 | awk '{ print $1 }'`; docker exec -it $DOCKER_ID /bin/bash
free -h # repeatedly run to inspect changes over time
Note that ElasticSearch memory usage peaks during ingest and indexing and then eventually settle down to a slightly lower number once indexing and consolidation is complete. So ideally peak memory usage should be tested during ingest.