How to Solve Elasticsearch Not Working Issue in Magento 2?

If you are experiencing issues with Elasticsearch not working in Magento 2, there are several steps you can take to troubleshoot and resolve the issue. Here are some possible solutions:

Check Elasticsearch status: Verify that Elasticsearch is running and its status is green. You can use the command curl -X GET 'http://localhost:9200/_cluster/health?pretty=true' to check the status. If the status is not green, there may be an issue with Elasticsearch that needs to be addressed.
Check Elasticsearch configuration: Make sure that the Elasticsearch configuration in Magento 2 is correct. Go to Stores > Configuration > Catalog > Catalog > Catalog Searchand verify that the Elasticsearch server hostname and port are correct. Also, check that the Elasticsearch index name and type are correct.
Check Magento 2 logs: Look for any errors or warnings related to Elasticsearch in the Magento 2 logs. You can find these logs in the var/log directory of your Magento 2 installation.

Reindex data: Try reindexing your data by going to System > Index Management and selecting all of the indexes related to Elasticsearch. Click on the "Submit" button to reindex the data.
Increase Elasticsearch memory: Elasticsearch may not be able to handle the amount of data you have in your store. Try increasing the memory allocation for Elasticsearch by editing the jvm.options file in the Elasticsearch installation directory.
Upgrade Elasticsearch: If you are using an outdated version of Elasticsearch, try upgrading to a newer version. Magento 2 recommends using Elasticsearch 7.x or later.
Check server requirements: Verify that your server meets the minimum requirements for running Elasticsearch with Magento 2. Check the Elasticsearch and Magento 2 documentation for more information.

By following these steps, you should be able to troubleshoot and resolve issues with Elasticsearch not working in Magento 2. If you continue to experience issues, it may be helpful to consult with a Magento 2 developer or Elasticsearch expert for further assistance.