Unknown operator – How to solve this Elasticsearch error

Unknown operator – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues that cause many errors.

This guide will help you check for common problems that cause the log ” Unknown operator ” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: parser and plugin.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to pinpoint the cause of many errors and provides suitable actionable recommendations how to resolve them (free tool that requires no installation).

Log Context

Log”Unknown operator {}”classname  is ExpressionBuilder.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

case EqlBaseParser.GT:
  return new GreaterThan(source; left; right; zoneId);
  case EqlBaseParser.GTE:
  return new GreaterThanOrEqual(source; left; right; zoneId);
  throw new ParsingException(source; "Unknown operator {}"; source.text());
  public Expression visitValueExpressionDefault(ValueExpressionDefaultContext ctx) {


Run the Check-Up to get a customized report like this:

Analyze your cluster