Using tcp port "9300" in the application.properties file but still getting "None of the configured nodes are available"

Question

Error:

failed to load elasticsearch nodes : org.elasticsearch.client.transport.NoNodeAvailableException: None of the configured nodes are available: [{#transport#-1}{uyXiOMnyRpyTSXqUoNxTyg}{localhost}{127.0.0.1:9300}]

Versions:

Spring-Boot version: 2.1.6 and Elasticsearch version: 7.3.0

Here is my elasticsearch.yml file:

# ======================== Elasticsearch Configuration =========================
#
# NOTE: Elasticsearch comes with reasonable defaults for most settings.
#       Before you set out to tweak and tune the configuration, make sure you
#       understand what are you trying to accomplish and the consequences.
#
# The primary way of configuring a node is via this file. This template lists
# the most important settings you may want to configure for a production cluster.
#
# Please consult the documentation for further information on configuration options:
# https://www.elastic.co/guide/en/elasticsearch/reference/index.html
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
cluster.name: elastic
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
#node.name: node-1
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
path.data: D:\JEE_Projects\spring\Spring_WorkSpace\spring-boot-with-mongodb
#
# Path to log files:
#
#path.logs: /path/to/logs
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
#network.host: 192.168.0.1
#
# Set a custom port for HTTP:
# http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.seed_hosts: ["host1", "host2"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
#gateway.recover_after_nodes: 3
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true

Here is my application.properties file:

#Local MongoDB config
spring.data.mongodb.uri=mongodb://localhost:27017/newtest


# App config
server.port=8080
spring.application.name=BootMongo
server.address=localhost

# elastic search

spring.data.elasticsearch.cluster-name=elastic

#spring.main.allow-bean-definition-overriding=true

#spring.data.elasticsearch.repositories.enabled = true
spring.data.elasticsearch.cluster-nodes =localhost:9300

I restarted the app, restarted the elasticsearch.bat and even restarted the whole computer but nothing is working.

Moreover, I thought some other applications would have occupied the port but it was occupied by elasticsearch itself. (I typed "localhost:9300" in the browser and it was responding as "This is not an HTTP port").

Answer 1

This question was asked by me and I found the solution.

There were 2 main internal problems:

1. In the latest versions (from 7.x onward I guess) of the Elasticsearch we can only have one "type" per index (Though it is deprecated to have more than one "type" in an index but still, forcefully we can use it). I was giving different "type" for every entity via @Document annotation but under the same index.
2. I downloaded the latest version of Elasticsearch i.e. 7.3.0. Since it's an emerging technology, it updates very frequently. But in spring, by default, the version of the Elasticsearch jar is 6.4.3 (You can see this by clicking on the Maven Dependencies)

Solutions:

For the first problem, you can create separate index for each entity. To solve second problem, either you can downgrade the version of the Elasticsearch to the 6.4.3 or you can upgrade the jar version in your Maven dependency to 7.3.0 (But in 7.3.0 jars, some built-in methods are bit different and may be unknown to you).

Answer 2

I guess that 'cluster-name=elastic' might be wrong. Are you sure elastic runs with such cluster name ?