Briefly, this error occurs when a character that is not allowed for escaping is used in Elasticsearch queries. Elasticsearch uses certain special characters in its query syntax and if these characters are not properly escaped, it can lead to errors. To resolve this issue, ensure that you are using the correct escape characters in your queries. You can also use the Elasticsearch Query String Syntax to understand how to properly format your queries. Additionally, check your data input for any unexpected characters that might be causing this error.
This guide will help you check for common problems that cause the log ” Char [{}] cannot be used for escaping ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: parser, plugin.
Log Context
Log “Char [{}] cannot be used for escaping” class name is ExpressionBuilder.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
throw new ParsingException(source(escapeCtx); "A character not a string required for escaping; found [{}]"; escapeString);
} else if (escapeString.length() == 1) {
escape = escapeString.charAt(0);
// these chars already have a meaning
if (escape == '*' || escape == '%' || escape == '_') {
throw new ParsingException(source(escapeCtx.escape); "Char [{}] cannot be used for escaping"; escape);
}
// lastly validate that escape chars (if present) are followed by special chars
for (int i = 0; i < pattern.length(); i++) {
char current = pattern.charAt(i);
if (current == escape) {
