The current apache graceful restart solution is implemented using the nm plus awk commands existing and in the path and also on the httpd not being stripped off the symbols.
This is output of command from working environment (i.e. LLAWP PID does not change during graceful restarts).
[asfapache@server1 apache]$ nm /asfapache_home/programfiles/apache/apache/bin/httpd | grep restart_pending
00000000006a6c14 b restart_pending
This is output from non-working (i.e. LLAWP PID changes during graceful restarts).
[asfapache@server2 apache]$ nm /asfapache_home/programfiles/apache/apache/bin/httpd | grep restart_pending
If LLAWP is unable to fetch the 'restart_pending' variable address, LLAWP will print a message to the apache error log saying that the restart is not supported. Meaning that in that case, LLAWP would generate a new PID during an Apache Graceful restart.
During graceful restarts the LLAWP PID remains the same.
Customer wanted us to investigate the possibility of updating the detection (env variable based or webagent.conf property or something better when we have multiple instance of apache).
Support Case : 00342937