Tokenization is empty – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 8-8.9

Briefly, this error occurs when Elasticsearch attempts to tokenize a field but the field is empty or null. This could be due to incorrect data input or a misconfigured analyzer. To resolve this issue, you can ensure that the field being tokenized contains valid, non-null data. Alternatively, you can adjust your analyzer settings to handle empty fields appropriately, such as by skipping them or assigning a default value.

This guide will help you check for common problems that cause the log ” tokenization is empty ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “tokenization is empty” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 NlpTokenizer tokenizer;
 int numResults;
 String resultsField
 ) {
 if (tokenization.isEmpty()) {
 throw new ElasticsearchStatusException("tokenization is empty"; RestStatus.INTERNAL_SERVER_ERROR);
 }  if (tokenizer.getMaskTokenId().isEmpty()) {
 throw ExceptionsHelper.conflictStatusException(
 "The token id for the mask token {} is not known in the tokenizer. Check the vocabulary contains the mask token";


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