Complete the following prerequisite before you install the external Elasticsearch nodes:
If you have installed the external nodes Elasticsearch 5.6.13 with Sentinel 8.3 or prior version, uninstall the Elasticsearch, and then install the Elasticsearch 7.7.0 version. For installation, see Installing and Configuring Elasticsearch.
Based on your EPS rate, deploy Elasticsearch in a cluster mode with the number of nodes and the number of replicas as recommended in Sentinel System Requirements.
Set the file descriptors by adding the following properties in the /etc/security/limits.conf file:
elasticsearch hard nofile 65536
elasticsearch soft nofile 65536
elasticsearch soft as unlimited
NOTE:After you complete the above prerequisites, run the sysctl -p command to reload the changes made to the files.