Esockettimedout error in xsjs

Have a nodejs module in mta project also another nodejs module in another mta project.

In both project xsjs code is there. 1st xsjs service making an http service call to xsjs to 2nd app through xsjs APi net.http.client. but it is giving ESOCKETTIMEDOUT error when multiple user hit first service at a time. For total of 5, 2 success and 3 failed with ESOCKETTIMEDOUT error.

Any idea why so?