<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap:break-word;line-break:after-white-space"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> We have been trying to upgrade the Nginx binary on the fly by invoking USR2 </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> signal to spawn a new set of master and worker processes with the new </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> configuration. The question I have is when this new master process is </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> spawned, after issuing USR2 signal to the existing or the old master </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> process, what would be it's parent process? Will it be the root process (1) </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> or the old master process? </span><div><font face="helvetica Neue, helvetica"><span style="font-size:14px">></span></font></div><div><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> We have been seeing different case of this. In some cases we have seen the </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> new master process' PPID is 1, whereas in other cases its PPID is that of </span><br style="font-family:"helvetica Neue",helvetica;font-size:14px"><span style="font-family:"helvetica Neue",helvetica;font-size:14px">> the old master process. </span><font face="helvetica Neue, helvetica"><span style="font-size:14px"><br></span></font><div><br></div><div><font face="helvetica Neue, helvetica"><span style="font-size:14px">The new master’s parent is the old master before you quit the old master process, </span></font></div><div><font face="helvetica Neue, helvetica"><span style="font-size:14px">after it quits, the new master’s parent process will be the init process.</span></font></div></div></body></html>