Magento 2.4.0 - Getting Error Could not validate a connection to Elasticsearch. No alive nodes found in your cluster

I upgraded my Magento 2.3.5 into 2.4.0 and now facing this error, very annoying to say the least,... I fixed it by disabling the Elastic Search module... injecting this into a Magento "update" is totally un-called for, very frustrating and annoying.

After disabling these, my php /bin/magento setup:upgrade works fine now:

php bin/magento module:disable {Magento_Elasticsearch,Magento_InventoryElasticsearch,Magento_Elasticsearch6,Magento_Elasticsearch7}

I thought upgrading into 2.4.0 would make life better, I can't believe there are so many problems just to get into 2.4.0.... don't know what I am walking into, ... I hope my installation that I am about to deploy does not break as a result of so many unwanted modules added into the 2.4.0 update before even trying it yet!...

The issue is the ElasticSearch config in your command.

To start the verification, you can run this curl command below to validate your ElasticSearch, you can change the host elasticsearch to your host.

curl elasticsearch:9200

These are the issues in your commands:

1º - Don't specify the ElasticSearch host

2º - It's using MySQL which is not supported

3º - It seems to be a generic configuration and not the right one, as your password is changeme

Try this command below.

php -d memory_limit=-1 bin/magento setup:install \
--base-url="http://127.0.0.1/magento240" \
--db-host="127.0.0.1" \
--db-name="magento240" \
--db-user="root" \
--db-password="root123" \
--admin-firstname="admin"  \
--admin-lastname="admin"  \
--admin-email="[email protected]"  \
--admin-user="admin"  \
--admin-password="admin123"  \
--language="en_US"  \
--currency="USD"  \
--timezone="America/Chicago"  \
--use-rewrites="1"  \
--backend-frontname="admin"  \
--elasticsearch-host=elasticsearch

I have installed Elasticsearch in my Linux Mint & It's working fine. Here is the steps.

Run the below command to Install Elasticsearch In locally.

Download and install the public signing key :

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -

Installing from the APT repositoryedit

You may need to install the apt-transport-https package on Debian before proceeding :

sudo apt-get install apt-transport-https

Save the repository definition to /etc/apt/sources.list.d/elastic-7.x.list :

echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-7.x.list

You can install the Elasticsearch Debian package with :

sudo apt-get update && sudo apt-get install elasticsearch

Elasticsearch is not started automatically after installation. How to start and stop Elasticsearch depends on whether your system uses SysV init or systemd (used by newer distributions).

ps -p 1

Running Elasticsearch with SysV init : Use the update-rc.d command to configure Elasticsearch to start automatically when the system boots up :

sudo update-rc.d elasticsearch defaults 95 10

Elasticsearch can be started and stopped using the service command :

sudo -i service elasticsearch start

sudo -i service elasticsearch stop

Configure Apache and Elasticsearch : Set up a proxy (Set up a proxy for Apache 2.4)

Enable mod_proxy as follows :

a2enmod proxy_http or sudo a2enmod proxy_http

Use a text editor to open /etc/apache2/sites-available/000-default.conf

Add the following directive at the top of the file :

Listen 8080

Add the following at the bottom of the file :

<VirtualHost *:8080>
    ProxyPass "/" "http://localhost:9200/"
    ProxyPassReverse "/" "http://localhost:9200/"
</VirtualHost>

Restart Apache :

service apache2 restart or sudo service apache2 restart

Verify the proxy works by entering the following command :

For example, if your proxy uses port 8080:

curl -i http://localhost:8080/_cluster/health

If curl request success then messages display like below :

HTTP/1.1 200 OK
Date: Sun, 23 Aug 2020 06:05:56 GMT
Server: Apache/2.4.18 (Ubuntu)
content-type: application/json; charset=UTF-8
content-length: 389

{"cluster_name":"elasticsearch","status":"yellow","timed_out":false,"number_of_nodes":1,"number_of_data_nodes":1,"active_primary_shards":1,"active_shards":1,"relocating_shards":0,"initializing_shards":0,"unassigned_shards":1,"delayed_unassigned_shards":0,"number_of_pending_tasks":0,"number_of_in_flight_fetch":0,"task_max_waiting_in_queue_millis":0,"active_shards_percent_as_number":50.0}

Go to Admin Panel -> Stores -> Settings -> Configuration -> Catalog -> Catalog Search. Change the settings like below.

Search Engine : Search Engine7

Elasticsearch Server Hostname : localhost

Elasticsearch Server Port : 8080

Elasticsearch Index Prefix : magento2

Enable Elasticsearch HTTP Auth : No

Elasticsearch Server Timeout : 15

Now save the configuration & run below cache clean command.

php bin/magento cache:clean

Now click on Test Connection button.

After successful you will receive Successful! Test again? in Test Connection button.

Ref : Dev Docs & Elasticsearch

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