I have update nginx.conf file in API Node and need to restart only nginx instance without restarting other services, please suggest.
If I restart dss , by default the nginx will also restart.
Nginx server is maintained by supervisor one. So you cannot just restart nginx process only. You will need to restart DSS via dss binary.
Having said this, you can force nginx server (including worker) to stop by kill command and supervisor will spawn the new process:
[dataiku@702api data_dir_api]$ ps -ef | grep nginx dataiku 1847 1843 0 04:24 ? 00:00:00 nginx: master process /usr/sbin/nginx -c /home/dataiku/data_dir_api/install-support/nginx.conf dataiku 1901 1847 0 04:24 ? 00:00:00 nginx: worker process dataiku 1944 1585 0 04:25 pts/0 00:00:00 grep --color=auto nginx [dataiku@702api data_dir_api]$ kill -9 1901 1847 [dataiku@702api data_dir_api]$ ./bin/dss status apimain RUNNING pid 1846, uptime 0:01:19 nginx STARTING [dataiku@702api data_dir_api]$ ./bin/dss status apimain RUNNING pid 1846, uptime 0:01:26 nginx RUNNING pid 1945, uptime 0:00:11
As you can see, the new PID was generated for nginx server. Please give it a try and check if this works for you.
UPD: You can also simply use
./dss restart nginx