1. (Optional) Enter Server Username used to access the enterprise search server.
2. (Optional) Enter Server Password associated with the username.
3. Set Enable Cluster Sniffing (Optional). Sniffing finds and connects to all data nodes in your cluster automatically.

<Warning>

Do not enable cluster sniffing when using cloud-hosted search providers such as Elastic Cloud or Amazon OpenSearch Service. Cloud providers typically hide search cluster nodes behind a proxy, so sniffed node addresses may be unreachable from your network. The provider handles connection pooling for you, making sniffing unnecessary and potentially disruptive.

</Warning>

4. Optional CA and client certificate configuration settings are available for use with basic authentication credentials or to replace them. See the Enterprise search configuration settings documentation for details.
5. Select Test Connection and then select Save. If the server connection is unsuccessful you won't be able to save the configuration or enable searching with Elasticsearch or AWS OpenSearch.

<Note>

From Mattermost v11, enterprise search server connections are tested during Support Packet generation. Any connection errors encountered during Support Packet generation are automatically included in the packet to help diagnose configuration issues.

</Note>

Build the post index of existing messages

Select Index Now. This process can take up to a few hours depending on the size of the post database and number of messages. The progress percentage can be seen as the index is created. To avoid downtime, set Enable Elasticsearch for search queries to false so that database search is available during the indexing process.

Enable enterprise search

Ensure bulk indexing is complete before enabling enterprise search, otherwise search results will be incomplete.

Set Enable Elasticsearch for search queries to true, and setting Enable Elasticsearch for autocomplete to true. Save your configuration updates and restart the Mattermost server.

<Note>

For high post volume deployments, we strongly encourage you to read and properly configure the Mattermost LiveIndexingBatchSize configuration setting.

</Note> <Warning>

For high post volume deployments, we also strongly recommend disabling Database Search once Elasticsearch or AWS OpenSearch is fully configured and running. The Mattermost Server will fall back on Database search if ElasticSearch or OpenSearch are unavailable which can lead to performance degradation on high post volume deployments.

</Warning>

Once the configuration is saved, new posts made to the database are automatically indexed on the Elasticsearch or AWS OpenSearch server.

Enterprise search limitations

1. Elasticsearch and AWS OpenSearch uses a standard selection of "stop words" to keep search results relevant. Results for the following words will not be returned: "a", "an", "and", "are", "as", "at", "be", "but", "by", "for", "if", "in", "into", "is", "it", "no", "not", "of", "on", "or", "such", "that", "the", "their", "then", "there", "these", "they", "this", "to", "was", "will", and "with".
2. Searching stop words in quotes returns more results than just the searched terms (ticket).
3. By default, search results are limited to a user's team and channel membership. This is enforced by the Mattermost server. The entities are indexed in Elasticsearch or AWS OpenSearch in a way that allows Mattermost to filter them when querying, so the Mattermost server narrows down the results on every Elasticsearch or AWS OpenSearch request applying those filters. From Mattermost v11.6, admins can allow searching public channels without membership so that users can find messages in public channels they haven't joined, scoped to teams they belong to.