We wanted to verify whether the sharing created by running on a virtual machine made any significant statistical difference to the PingER results. Thus we compare the results from PinGER running on a bare metal machine (pinger.slac.stanford.edu) vs running on a VM.
Spin up the virtual machine.
Install pinger2.pl
Verify installation
These are CGI scripts to enable a reverse traceroute and ping server (traceroute.pl), and to enable the gathering of data (ping_data.pl) from the archive sites. The two scripts were installed in the standard CGI script location /var/www/cgi-bin as defined in /etc/httpd/conf/http.conf. They are accessible from within SLAC as: http://dhcp-nebula-124-66.slac.stanford.edu/cgi-bin/ping_data.pl and http://dhcp-nebula-124-66.slac.stanford.edu/cgi-bin/traceroute.pl. Since they are on port 80 there is no access to the web server from offiste.
To ensure the web server (Apache) restarts after a reboot I also had to issue:
[cottrell@dhcp-nebula-priv-52-7 ~]$ sudo -s [sudo] password for cottrell: [root@dhcp-nebula-priv-52-7 cottrell]# /sbin/chkconfig httpd on [root@dhcp-nebula-priv-52-7 cottrell]# /etc/init.d/httpd restart Stopping httpd: [FAILED] Starting httpd: [ OK ] [root@dhcp-nebula-priv-52-7 cottrell]# ps -efl | grep httpd 1 S root 3056 1 0 80 0 - 46710 poll_s 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3058 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3059 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3060 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3061 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3062 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3063 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3064 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 5 S apache 3065 3056 0 80 0 - 46710 inet_c 07:42 ? 00:00:00 /usr/sbin/httpd 0 S root 3083 3029 0 80 0 - 26328 pipe_w 07:46 pts/0 00:00:00 grep httpd |
See here
On March 6, 2015 around 6:30pm, Yee reconfigured the VM to use a fixed address. The IP address is now 172.23.52.7. This host can only be seen from SLAC.
I changed:
I created another NODE_DETAILS record for 172.23.52.7 and disabled dhcp-nebula-124-66.slac.stanford.edu. The new services are now at:
Traceroutes from pinger to pingervm and from pingervm to pinger.
Analysis of measurements from March 10, 2015 16:30 through March 13, 2015 23:45, i.e. approximately 3000 pings, showed a difference (pinger>pingervmfix - pingervmfix>pingert) in minimum RTT of of ~ 0.045 +- 0.02 ms
176cottrell@pinger:~$ssh 172.23.52.7 =============================================================================== NOTICE TO USERS This is a Federal computer system and is the property of the United States ... stated in this warning. =============================================================================== RHEL Server 6.7 (Santiago) 2.6.32-504.16.2.el6.x86_64 (1x2099MHz OpenStack Nova) =============================================================================== WINSTART: Undefined variable. 169cottrell@dhcp-nebula-priv-52-7:~$ |