Refuses remote connections

Check: network.host in opensearch.yml. Fix: Local-only by design; enable security plugin before binding outward.

Node won't start: max_map_count

Check: sysctl vm.max_map_count. Fix: Image presets 262144; if overridden, restore /etc/sysctl.d/99-opensearch.conf.

Yellow cluster health

Check: Single node + replicated index settings. Fix: Set number_of_replicas: 0 for single-node indices or add nodes.

Troubleshoot OpenSearch (Hardened) — DC Associates Group Docs

Symptom	Check	Fix
Refuses remote connections	network.host in opensearch.yml	Local-only by design; enable security plugin before binding outward.
Node won't start: max_map_count	sysctl vm.max_map_count	Image presets 262144; if overridden, restore /etc/sysctl.d/99-opensearch.conf.
Yellow cluster health	Single node + replicated index settings	Set number_of_replicas: 0 for single-node indices or add nodes.

Logs & useful commands

/var/log/opensearch; `journalctl -u opensearch -f`
Health: curl -s http://127.0.0.1:9200/_cluster/health | jq .status → green (single node: yellow for replicated indices is normal)
First boot state: Node data directory initializes fresh on first start (build-time state is wiped). vm.max_map_count preset via sysctl.

Still stuck? Email support@dcassociatesgroup.com with the product name, cloud + region, instance size, and the output of the health command — first response within 1 business day, most tickets same-day.