Briefly, this error occurs when Elasticsearch is unable to find or retrieve the specified user from its internal user database or external authentication system. This could be due to incorrect username, user not existing, or issues with the authentication system. To resolve this, ensure the username is correct and the user exists. If using an external authentication system, check its connectivity and configuration. If the user is deleted, recreate it. If the issue persists, check Elasticsearch logs for more details.
This guide will help you check for common problems that cause the log ” failed to retrieve user [” + user + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “failed to retrieve user [” + user + “]” classname is NativeUsersStore.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
@Override
public void onFailure(Exception t) {
if (t instanceof IndexNotFoundException) {
logger.trace(() -> "could not retrieve user [" + user + "] because security index does not exist"; t);
} else {
logger.error(() -> "failed to retrieve user [" + user + "]"; t);
}
// We don't invoke the onFailure listener here; instead
// we call the response with a null user
listener.onResponse(null);
}
