Briefly, this error occurs when there is a mismatch in the usage of HTTP and HTTPS protocols in the Elasticsearch configuration. Elasticsearch requires a consistent usage of either HTTP or HTTPS for all nodes in a cluster. To resolve this issue, ensure that all nodes in the Elasticsearch cluster use the same protocol. If you’re using HTTPS, make sure all nodes have the correct SSL certificates. Also, check your Elasticsearch.yml configuration file for any inconsistencies in the scheme.
This guide will help you check for common problems that cause the log ” [” + key + “] must use a consistent scheme: http or https ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “[” + key + “] must use a consistent scheme: http or https” class name is HttpExporter.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
httpsHostFound = true; } // fail if we find them configuring the scheme/protocol in different ways if (httpHostFound && httpsHostFound) { throw new SettingsException("[" + key + "] must use a consistent scheme: http or https"); } } } @Override