Not a valid regular expression file – How to solve this Elasticsearch error

Not a valid regular expression file – 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 ” not a valid regular expression file ” 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: Node.

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”not a valid regular expression file”classname  is UserAgentParser.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

}
  }
  }
 
  if (uaPatterns.isEmpty() && osPatterns.isEmpty() && devicePatterns.isEmpty()) {
  throw new ElasticsearchParseException("not a valid regular expression file");
  }
  }
 
  private Pattern compilePattern(String regex; String regex_flag) {
  // Only flag present in the current default regexes.yaml

Run the Check-Up to get customized recommendations like this:

checklist Run Check-Up

error

Heavy merges detected in specific nodes

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Description

A large number of small shards can slow down searches and cause cluster instability. Some indices have shards that are too small…

error-img

Recommendations Based on your specific ES deployment you should…

Based on your specific ES deployment you should…

1

X-PUT curl -H [a customized recommendation]

 

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