Invalid action name actionName must start with one of – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

Briefly, this error occurs when an action name in Elasticsearch does not start with the required prefix. Elasticsearch has certain conventions for action names, and they must start with specific prefixes. This error indicates that the action name you’ve used doesn’t follow these conventions. To resolve this issue, you should rename the action to start with one of the allowed prefixes. If you’re unsure of the correct prefix, refer to the Elasticsearch documentation or the source code where the action is defined.

This guide will help you check for common problems that cause the log ” invalid action name [” + actionName + “] must start with one of: ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .

Log Context

Log “invalid action name [” + actionName + “] must start with one of: ” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

    private static void validateActionName(String actionName) {
        // TODO we should makes this a hard validation and throw an exception but we need a good way to add backwards layer
        // for it. Maybe start with a deprecation layer
        if (isValidActionName(actionName) == false) {
            logger.warn("invalid action name [" + actionName + "] must start with one of: " + TransportService.VALID_ACTION_PREFIXES);

     * Returns true iff the action name starts with a valid prefix.