Go to the AWS Lambda function and search your ElasticSearch lambda function associated with your wanted ES instance. The name of the function should start with: LogsToElasticsearch_
Then in this JS file search for a code of line that generated the logging entry to be pushed to an ES index. This should be in a function named as: function transform(payload) {…}
In here search for the line that created the index: var indexName = [ … ]
Change it to the following(NOTICE: The index name must be in lower case):
var indexName = [
‘cwl-‘ + payload.logStream.toLowerCase() + “-” + timestamp.getUTCFullYear(), // year
(‘0’ + (timestamp.getUTCMonth() + 1)).slice(-2), // month
(‘0’ + timestamp.getUTCDate()).slice(-2) // day
].join(‘.’)