Event ID: 41309 Failed to communicate with Elasticsearch indexing engine.

Problem

Event ID: 41309 Failed to communicate with Elasticsearch indexing engine.

Error Message

Event ID: 41309 The following error message occurred in the core indexing engine: Failed to communicate with Elasticsearch indexing engine. Try restarting the Indexing Service to fix the issue.

Cause

Elasticsearch throws an error with the Event ID 41309 when Elasticsearch cannot complete its health check in 30 seconds (default setting).

Solution

Navigate to the EVIndexAdminService.exe.config file (for example, C:\Program Files (x86)\Enterprise Vault\EVIndexAdminService.exe.config) and create the following key:

<appSettings>
<add key="ES_HEALTH_CHECK_TIMEOUT" value="120"/>
</appSettings>

This can be inserted into the file just above the closing of the configuration line </configuration> as seen below.  

<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2"/></startup>
<appSettings>
<add key="ES_HEALTH_CHECK_TIMEOUT" value="120"/>
</appSettings>
</configuration>
 

Restart the Enterprise Vault indexing service.