I using using jetty to run Solr using the following cmd line: java -jar start.jar &
how can I stop this instance of solr gracefully?
Find the process id with
Better yet, you should really be using a proper service to run Solr - Tomcat can do this, or Jetty can be made to run as a service.
Start it (defining stop.port and stop.key variables):
then you can stop it: