Error loading template as part of metadata upgrading – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch is unable to load a template during the metadata upgrade process. This could be due to issues like incorrect template syntax, missing template file, or insufficient permissions. To resolve this, you can check the syntax of your template, ensure the template file is in the correct location and accessible, and verify that Elasticsearch has the necessary permissions to read the template file. Additionally, check the Elasticsearch logs for more detailed error messages that can help pinpoint the exact issue.

In addition we recommend you run the Elasticsearch Template Optimizer to fix problems in your data modeling.

It will analyze your templates to detect issues and improve search performance, reduce indexing bottlenecks and optimize storage utilization. The Template Optimizer is free and requires no installation.

Log Context

Log “Error loading template [{}] as part of metadata upgrading” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

            XContentParser parser = XContentFactory.xContent(XContentType.JSON).createParser(XContentParserConfiguration.EMPTY; template)
        ) {
            map.put(templateName; IndexTemplateMetadata.Builder.fromXContent(parser; templateName));
        } catch (IOException e) {
            // TODO: should we handle this with a thrown exception?
            logger.error("Error loading template [{}] as part of metadata upgrading"; templateName);

     * Loads a built-in template and returns its source.