A log file is created for the frontend requests:
var/log/Wyomind_ElasticsearchCore_Frontend_Requests.log

A log file is created for the reindexation process:
var/log/Wyomind_ElasticsearchCore_Indexation.log

A log file is created for the Elasticsearch client calls:
var/log/Wyomind_ElasticsearchCore_Client.log

A log file is created for the Elasticsearch Server status:
var/log/Wyomind_ElasticsearchCore_Server_Status.log

When the Elasticsearch Server status log is enabled, you can enable and define your own configuration for the backend notification subject and content.

Note that you have the possibility to use variables in the email content:

• {{store_id}}
  Store ID
• {{code}}
  Store code
• {{name}}
  Store name
• {{server_version}}
  Elasticsearch Server version
• {{servers}}
  Servers

When the Elasticsearch Server status log is enabled, you can enable and define your own configuration for the email notification.

Note that you have the possibility to use variables in the email content: 

• {{store_id}}
  Store ID
• {{message}}
  Returned message
• {{server_status}}
  Elasticsearch Server status
• {{server_version}}
  Elasticsearch Server version

Here will be displayed the version of the Elasticsearch server that you have installed.
6.3.2

The servers must be written as host:port and separated with a comma.
Follow this pattern for full available parameters.
Check that your servers are correctly configured by clicking on TEST servers.

This is only used for https connection. You can set that option to No if you don't have a valid SSL certificate.

Number of seconds after a timeout occurs for every request.
5 seconds

This is used to prefix index names in order to avoid potential collisions. 
demo_m2_

Having more shards enhances the indexing performance and allows to distribute a big index across machines and having more replicas enhances the search performance and improves the cluster availability.

This is where you can define the analysis settings.

Reindex in a temporary index and switch to it once finished. Especially useful for large product catalogs.

In some cases, you might need to reindex indexes automatically as it can take a lot of time. Then you can choose to automatically run indexers via a cron task when they are invalidated.

A notification is displayed in the header of Magento when indexes are invalidated.

If you disable this option, see how to run your indexes manually.

By default, it is set to AND. You may have fewer results with the AND operator but they’ll be more relevant.
"digital camera" is translated to "digital AND camera" or "digital OR camera"

This enables product weight modifier. It is only available for search results.

By enabling this option, when a product (configurable or bundle) is found from the data of a child product, then the parent product images will be used instead of the child product images.

Enable this option to return the products available for purchase before the products not available.

You can enable Category Search so that they can be indexed in Elasticsearch.

If you do, you need to select and configure the category attributes that are searchable.
Description
Name
Page Title
URL Key

You can enable the search among your CMS pages to be indexed in Elasticsearch.

You just need to select and configure the searchable attributes. 
Content, Content Heading, Identifier, Title

You also have the possibility to exclude some pages that may not be relevant from the search results. 
404 Not Found, Enable Cookies, Privacy Policy

When the Product Search is enabled, the products are indexed in Elasticsearch.

You can define the image size in pixels. 
50px

Then, select and configure the attributes that are searchable.
Product Name
SKU
Color
Description
Gender
Manufacturer

Choose the image you want to display when categories and search pages are loading. It can be:

• jpg
• jpeg
• gif
• png
  

Used for the main elements.

Generally used for highlighting search terms in the search results.

Generally used as the products listing background.

Generally used as the secondary entities listing and layers background.

Dark overlay behind the autocomplete popup.

Blurred background behind the autocomplete popup.

Smoothly show/hide the autocomplete popup.

If enabled, you can define the duration of the transition in seconds. 
0.2

There are 3 types of index:

• category
• cms
• products

In the Description column, when clicking on More information, you can see:

• demo_m2_default_category
  It is the name of the index at the Elasticsearch server level under the below format:
  the prefix + the storeview code + the index type
• 36 documents
  It means that 36 categories are indexed.
• 14,77 kB
  It is the size of the index on the disk.
• View Mapping
  When clicking on View Mapping, a popup should open and display the mapping data. 
  

The last time the index has been run will be recorded in the Last Update column. 

The last action state will be recorded in this column. You can also see the number of entities that were indexed by hovering the mouse over the status.

When running an index, a progress bar will display its status and some information about the indexing process.

From the Status column, you can see if the indexes are valid of invalidated. 

From the Action column, you can choose to:

• Flush the index: this will empty, reset the index.
• Run the index: this will fully reindex the entities.
• Run via cron: this will trigger the cron task to run the selected index.

To update the Elasticsearch server version with the right, you can use the below command line:

bin/magento wyomind:elasticsearchcore:update:server:version

To update the configuration file which is used on the frontend to avoid loading the full Magento Core, you can use the below command line:

bin/magento wyomind:elasticsearchcore:update:config

To reindex your data, you can use the below command line:

bin/magento wyomind:elasticsearchcore:indexer:reindex [options]

Options:

• -s storecode or --store storecode
  The code of the store view for which to re-index data.
  
  Note that this parameter is unique, you can’t add many store codes.

  To reindex all types for the store view which code is “storefr”:

  bin/magento wyomind:elasticsearchcore:indexer:reindex -s storefr

  or

  bin/magento wyomind:elasticsearchcore:indexer:reindex --store storefr

• -i type or --index type
  A space-separated list of index types: cms, category, and product
  
  

  To reindex products only:

  bin/magento wyomind:elasticsearchcore:indexer:reindex -i product

  or

  bin/magento wyomind:elasticsearchcore:indexer:reindex --index product

  You can also reindex your brands when using the Shop by Brand extension. 
• -p ID or --product ID
  The ID of the product to reindex. 
  
  Note that this parameter is unique, you can’t add many products.
  To reindex product with ID 2:
  

  bin/magento wyomind:elasticsearchcore:indexer:reindex -i product -p 2

  or 

  bin/magento wyomind:elasticsearchcore:indexer:reindex --index product --product 2

More examples:

To reindex all index types for all store views and products:

bin/magento wyomind:elasticsearchcore:indexer:reindex

To reindex categories for the store view which code is “storefr”:

bin/magento wyomind:elasticsearchcore:indexer:reindex -s storefr -i category

To reindex categories and CMS pages:

bin/magento wyomind:elasticsearchcore:indexer:reindex -i category cms

When running an index, a progress bar will display its status and some information about the indexing process.

To boost your products in the search results, you can give them a weight. For this, go in:
CatalogProducts

There, edit a product you want to showcase.

In the Wyomind Elasticsearch Core tab, you can define the weight from 1 to 10. 

You have the possibility to ignore products in the indexation process. For this, go in:
CatalogProducts

There, edit a product you want to showcase.

In the Wyomind Elasticsearch Core tab, you can switch the Ignore the product for indexation option to Yes. 

You can create new groups of synonyms from:
MarketingSeo & SearchSearch Synonyms

For example, if you create the list of synonyms:
shoes,footwear

This means that when searching for "orange shoes", the extension will search:
orange shoes
orange footwear

If other synonyms are defined such as:
red,orange,yellow

In that case, the extension will search:
red shoes
red footwear
orange shoes
orange footwear
yellow shoes
yellow footwear

All the corresponding products will then be displayed in the same list.