Nucleus .Net Core CMS

Elastic Search Extension

The Elastic Search extension provides a search index manager and a search provider (it both feeds the search index and retrieves search results).

The Elastic Search extension provides an interface to Elastic Search, but does not include the Elastic Search application. You need an Elastic Search server to use the Elastic Search provider. If you are setting up a new Elastic Search server, make sure to install the Ingest Attachment plugin.

Nucleus has built-in support for submitting pages and files to the index, and some modules (like the Documents module) also contain Search meta-data providers which submit search index entries.

The Elastic Search extension settings are accessed in the Manage control panel.

Elastic Search Settings


Elastic Search Server Url Enter the domain name or address of the Elastic Search server, including the scheme (http: or https:) and port. The default port is 9200. For example,
Index Name Enter an index name. The index is created automatically. Index names must be lower case, may not include , /, *, ?, ", <, >, |, (space character) or # and must be less than 255 bytes.
User name, password Enter your Elastic Search user name and password. If your Elastic Search server does not have security configured, you can leave these fields empty.
Certificate Thumbprint Enter your Elastic Search certificate thumbprint. If your Elastic Search server does not have a certificate configured, you can leave this value blank.
Attachments Size Limit You can specify an upper size limit (in mb) for documents which are submitted to the index. Documents which are larger than the size limit will have index entries containing meta-data only. To specify no limit, enter zero (0).
Indexing Pause You can specify an pause in-between each indexing operation (in seconds), or zero for no pause. See additional information below.
Boost Settings You can increase or decrease the boost for some search index fields. This influences the relevance of a document when you are searching, and results are sorted by relevance. The default boost value for all fields is 1.
- Title Boost the page title, or the file name for files.
- Summary Boost the page summary (not relevant for files).
- Categories Boost categories. Page and file index entries do not currently set categories, but modules may set one or more categories for an index entry.
- Keywords Boost page keywords (not relevant for files).
- Content Boost the page or file content. Elastic search can parse a number of file formats, including office documents and PDFs.
- Attachment Fields (Title, Name, Author, Keywords) Some document formats contain embedded meta-data. Use the attachment fields boost to increase the relevance of these values.

Indexing Pause

The indexing pause is used to reduce the load on your server during search feed processing. In some hosting environments, the search feed can exhaust memory, processor or TCP connection limits.

Pausing in-between submitting each index entry gives the server time to free up resources. This setting makes your search feed take longer to run, but can prevent it from failing. If you are hosting in an Azure App Service, this setting is important, as Azure automatically stops and restarts applications which have too many TCP ports open.

If you are hosting in Azure, try an indexing pause of 2.5 seconds. This will reduce the number of HTTP requests to 24 per minute, which gives the Azure time to release unused SNAT ports. For a search index with 5000 entries, this would increase the search feed duration to around 3.5 hours.


Get Index Count Displays the number of entries in the index, for use when troubleshooting or verifying that your server is functioning correctly.
Get Index Settings Displays Elastic Search configuration information.
Clear Index Use the Clear Index function to delete your index. It will be automatically re-created the next time that the index feeder task runs.

Nucleus has a built-in Scheduled Task which collects data from all installed search meta-data providers, and submits that data to all installed search index managers. You must create and enable the scheduled task in the Settings/Scheduler control panel as it is not enabled by default.

Elastic Search Scheduled Task

See Also: Setting up Self-Managed Elastic Search on a Azure Virtual Machine running Ubuntu Linux