Elasticsearch installation error

Hello everyone

we run the gitlab enterprise (13.3.4-ee) and we want to install elasticsearch with gitlab for a more detailed research

we got a few problems while installing elasticsearch on gitlab.
I followed this documentation on Elasticsearch integration | GitLab

the installation was successfull with this trace :

install -d /usr/local/bin
install -m755 bin/gitlab-elasticsearch-indexer /usr/local/bin

in the same time we completed the gitlab.rb with those lines :

ElasticSearch (EE only)

gitlab_rails[‘elasticsearch_enabled’] = true
gitlab_rails[‘elasticsearch_host’] = “lda1i185.server.lan”
gitlab_rails[‘elasticsearch_port’] = 9200

the next step would be to create a new index with sudo gitlab-rake gitlab:elastic:create_empty_index

we had the following error when we execute it :

Elasticsearch::Transport::Transport::Errors::ServiceUnavailable: [503]
/opt/gitlab/embedded/service/gitlab-rails/ee/lib/gitlab/elastic/helper.rb:91:in index_exists?' /opt/gitlab/embedded/service/gitlab-rails/ee/lib/gitlab/elastic/helper.rb:34:in create_empty_index’
/opt/gitlab/embedded/service/gitlab-rails/ee/lib/tasks/gitlab/elastic.rake:69:in block (3 levels) in <top (required)>' /opt/gitlab/embedded/bin/bundle:23:in load’
/opt/gitlab/embedded/bin/bundle:23:in `’
Tasks: TOP => gitlab:elastic:create_empty_index

we don’t understand this error, can someone help us ?

Thank you for your help

Kind regards