Briefly, this error occurs when there is an attempt to use a join field in Elasticsearch, but the field is not properly defined or the parent-child relationship is not correctly set up. To resolve this issue, ensure that the join field is correctly defined in the mapping and that the parent-child relationship is properly established. Also, check if the parent document is indexed before the child document. Lastly, ensure that both parent and child documents are in the same shard.
This guide will help you check for common problems that cause the log ” [” + NAME + “] join field [ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: query, join.
Log Context
Log “[” + NAME + “] join field [” class name is HasChildQueryBuilder.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
if (joiner.childTypeExists(type) == false) {
if (ignoreUnmapped) {
return new MatchNoDocsQuery();
} else {
throw new QueryShardException(context; "[" + NAME + "] join field [" + joiner.getJoinField() +
"] doesn't hold [" + type + "] as a child");
}
} String parentJoinField = joiner.parentJoinField(type);
