Briefly, this error occurs when Elasticsearch tries to parse a watch definition but encounters a null token. This usually happens when the watch JSON is malformed or empty. To resolve this issue, you can: 1) Check the watch definition for any syntax errors or missing fields. 2) Ensure that the watch JSON is not empty. 3) Validate the JSON format using a JSON validator. 4) If the error persists, consider recreating the watch with the correct syntax and format.
This guide will help you check for common problems that cause the log ” could not parse watch [{}]. null token ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “could not parse watch [{}]. null token” class name is WatchParser.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
String currentFieldName = null;
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == null) {
throw new ElasticsearchParseException("could not parse watch [{}]. null token"; id);
} else if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (currentFieldName == null) {
throw new ElasticsearchParseException("could not parse watch [{}]; unexpected token [{}]"; id; token);
} else if (WatchField.TRIGGER.match(currentFieldName; parser.getDeprecationHandler())) {
