Running unit tests after starting elasticsearch
It is happening because you starting elasticsearch command in blocking way. It means command will wait until elasticsearch server is shutdown. Jenkins just keep waiting.
You can use following command
./elasticsearch 2>&1 >/dev/null &or
nohup ./elasticsearch 2>&1 >/dev/null &it will run command in non-blocking way.
You can also add small delay to allow elasticsearch server start
nohup ./elasticsearch 2>&1 >/dev/null &; sleep 5