Briefly, this error occurs when a field in Elasticsearch is assigned a null value, which is not allowed. Elasticsearch requires all fields to have a value. To resolve this issue, you can either assign a default value to the field when it’s null or ensure that the field always has a value before indexing. Alternatively, you can use the “ignore_malformed” option to ignore such errors, but this might lead to data loss or incorrect data in your index.
This guide will help you check for common problems that cause the log ” Property [value] of field [” + name + “] can’t be [null]. ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “Property [value] of field [” + name + “] can’t be [null].” class name is ConstantKeywordFieldMapper.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
public Mapper.Builder> parse(String name; Mapnode; ParserContext parserContext) throws MapperParsingException { Object value = null; if (node.containsKey("value")) { value = node.remove("value"); if (value == null) { throw new MapperParsingException("Property [value] of field [" + name + "] can't be [null]."); } if (value instanceof Number == false && value instanceof CharSequence == false) { throw new MapperParsingException("Property [value] of field [" + name + "] must be a number or a string; but got [" + value + "]"); }