In an effort to separate our windows logging from our Infrastructure logging we are moving our Windows events to ELK and keeping our infrastructure on Splunk. After years of data collection on splunk we don't want to lose our legacy data from windows events. How can we extract that data from Splunk and move it to our ELK appliance?
1) you can use restpi of splunk and fetch data by writing search and take raw data from search and send to logstash and then send data to Elasticsrarch.
2) run search in splunk and store data (raw) in csv file and read csv file by logstash and send data to Elasticsrarch
your search||outputlookup csvfile
field extraction you can do in logstash.
If it takes too much time to fetch the data then you can divide your time (earliest and latest) in search