Wordpress https and time spent downloading a page

could be something with your web host network connectivity with google or googles end. What day was that spike ? As i saw a similar spike for this forum on Sept 4, 2016 AEST probably due to Linode's DDOS attacks recently



those download page speed numbers are not indicative of your users download speeds

for that, use webpagetest.org for real page speed numbers

my forum's Google Analytics pagespeed numbers also confirm a temp spike in page load times for my visitors - particularly it seems to affect mainly my mobile visitors



For me it was due to a higher portion of China + India visitors to the forum due to their average slower ISP speeds, they pulled down my page speed time averages! China average dom interactive and page load time was 32.8 and 61.98 seconds respectively !



Actually could make sense if Linode's DDOS attack origin was from China, so Linode's DDOS mitigation process might have slowed or blocked traffic from China ??

 

Also was your site on https previously or just switched from http to https with Centmin Mod ? as that could also factor in depending on your web server's https and encryption performance as older generation cpus aren't as fast at processing https as new processors. For Centmin Mod Nginx HTTP/2 benefits also use webpagetest.org to check speedindex scores for perceived page render time and not just total page load times. In Google Analytics that metric closely relates to Content DomInteractive time in pagespeed section of GA.

What date did you switch to Centmin Mod ? and new server ?

 

did a webpagetest.org test of your site and result at WebPagetest Test Result - Dulles : dulles...www.webeconomia.it/ - 09/07/16 15:31:48

seems probably is your web server backend slowness. Look at waterfall WebPagetest Test Details - Dulles : dulles...www.webeconomia.it/ - 09/07/16 15:31:48

TTFB is at almost 6 seconds so default backend issues i.e. mysql slow queries or general issues with server processing capabilities. What was the old and new server's hardware specs and which web host/plans did you move from and to ?

This was done on webpagetest.org dulles, USA speed test location so geographic location might factor into it though so might want to test from location closer to your visitors



example from this forum from same Dulles, USA location. FYI this forum server is in Fremont, USA Linode

 

FYI your HTTPS version of your site performs much better than above HTTP one probably due to HTTP/2 benefits for many page element requents due to HTTP/2 multiplexing

 

reminds me, if you switched from http to https default for new Centmin Mod install/server, did you update webmaster tool url for your domain ? if webmaster tool was setup http and not https, you need a new webmaster tool site profile added for https version

 

You might want to switch back to using WP Super Cache or better yet try out better performing KeyCDN Cache Enabler Wordpress - WP Cacher Enabler Plugin by KeyCDN folks | Centmin Mod Community

But there's so many factors beyond just the server as to why google webmaster bot's page download times can spike etc

I'd maybe also give it a few days to see how webmaster tool page download speed updates

 

Here's my Centmin Mod Wordpress7 site numbers

see unexplained spike a few months back they do happen

 

WP-FFPC guide is pretty outdated and old. The recommended Wordpress cache plugin now is using KeyCDN Cache Enabler WP Plugin as it's the default installed in Centmin Mod 123.09beta01's centmin.sh menu option 22 wordpress installer now. Instead of WP Super Cache or WP-FFPC.

 

3rd post has manual instructions Wordpress - WP Cacher Enabler Plugin by KeyCDN folks | Centmin Mod Community

 

it's also about how it's implemented in code and WP-FPPC is slower and well limited as back then memcached server was limited to objects <1MB in size and max character length in memcache php extension i.e. if your site is non-english and language's urls are lengthy you'd run into problems Problem memcached and long urls | Centmin Mod Community

could be your issue if your using non-english forum

conclusion at Problem memcached and long urls | Centmin Mod Community

 

no real needed for object cache as full page cache for keycdn cache enabler means nothing touches php and mysql backends as nginx handles it has full page static cache

 

Could be mysql related or php-fpm/mysql. Below are some guides and links to info you can use for diagnosing your issues. TLS nginx patch means using 1369 optimal. But shouldn't be a problem causing such TTFB issues unless the problem is the server and/or it's network connectivity itself. You can confirm by just setting up a test static page only on your domain i.e. domain.com/test.html and webpagetest that to confirm if nginx itself is okay. Then test domain.com/test.php with maybe some test php code and webpagetest.org to confirm for php-fpm. Then that leaves MySQL end (MariaDB server). Which below has links to mysqlmymonlite.sh tool etc.

Centmin Mod is provide as is, so short of scripted related bugs or issues, any further optimisation to the web stack components - nginx, php-fpm, mariadb mysql, csf firewall etc or web app specific configurations are left to the Centmin Mod user to deal with. So I do not provide any free support for such.

Slowness/timesout like with bad gateway 502 /504 timeouts are usually related to Nginx timing out waiting on PHP-FPM to respond as PHP-FPM is overloaded or overwhelmed with requests, so may need to tune PHP-FPM values. It also maybe due to PHP-FPM in turn being queued and backed up waiting on MariaDB MySQL server to respond - so also need to look at MySQL.

You'll need to tune your PHP-FPM settings and this is left up to end user to do but here's a thread for starters to enable php status page output outlined at http://centminmod.com/phpfpm.html#browserstatus and https://community.centminmod.com/threads/pm-max_children.479/ and https://community.centminmod.com/threads/warning-pool-www-server-reached-max_children-setting-50-consider-raising-it.791/ which outlines the official PHP-FPM config documentation as well.

Checking PHP-FPM etc logs

You'll also need to check into your PHP-FPM, Nginx and MariaDB logs which you can find as outlined at How to troubleshoot Centmin Mod initial install issues

Server logs include Nginx, PHP-FPM, MariaDB MySQL error logs as well as others. You can find your Centmin Mod install/menu logs at FAQ 7 and server logs at FAQ 19 at Centmin Mod FAQ (most up to date info in FAQ so always read that first). Spoiler tag below has info too but may not be up to date.

Some of Centmin Mod's installed software will have their own access and error logs which maybe useful for diagnosing errors or give info, notes, or warning notices.

Note: There's no support provided by me for diagnosing such errors which may occur for various reasons including misconfiguration of installed php/mysql scripts or applications.

In SSH2 telnet you can use tail command to view the last X number of lines in the file.

For example for viewing last 10 lines in the file for:

For Nginx access and error logs:

Code:

  tail -10 /usr/local/nginx/logs/access.log
  tail -10 /usr/local/nginx/logs/error.log

For specific domainname.com access and error log:

Code:

  tail -10 /home/nginx/domains/domainname.com/log/access.log
  tail -10 /home/nginx/domains/domainname.com/log/error.log

For other system error logs located at /var/log:

list /var/log files in ascending time order so the most recently modified files are at the bottom

Code:

  ls -lhrt /var/log

Code:

total 2.7M
-rw------- 1 root  root    0 Aug 29 15:33 tallylog
-rw------- 1 root  root    0 Aug 29 15:33 spooler
drwx------ 3 root  root 4.0K Aug 29 15:35 samba
drwxr-xr-x 2 root  root 4.0K Aug 29 15:35 mail
-rw-r--r-- 1 root  500     0 Oct  8 18:13 dmesg.old
-rw------- 1 root  500     0 Oct  8 18:13 boot.log
-rw-r--r-- 1 root  500     0 Oct  8 18:14 dmesg
drwx------ 2 root  root 4.0K Oct  8 18:14 httpd
drwxr-xr-x 2 root  root 4.0K Oct  8 19:08 php-fpm
-rw-rw---- 1 mysql root 2.3K Oct  9 12:38 mysqld.log
-rw------- 1 root  root 9.2K Oct 26 10:48 yum.log
-rw------- 1 root  utmp  94K Nov  7 22:59 btmp
drwxr-xr-x 2 root  root 4.0K Nov  8 00:00 sa
-rw------- 1 root  root 269K Nov  8 21:39 messages
-rw------- 1 root  root 110K Nov  8 23:08 secure
-rw-rw-r-- 1 root  utmp  43K Nov  8 23:08 wtmp
-rw-r--r-- 1 root  root 144K Nov  8 23:08 lastlog
-rw------- 1 root  root  69K Nov  8 23:08 lfd.log
-rw------- 1 root  root 332K Nov  8 23:08 maillog
-rw------- 1 root  500  1.6M Nov  8 23:10 cron

For PHP-FPM error log:

Code:

  tail -10 /var/log/php-fpm/www-error.log

and/or

Code:

  /var/log/php-fpm/www-php.error.log

For MySQL / MariaDB error log:

Code:

  tail -10 /var/log/mysqld.log

For CSF firewall LFD log:

Code:

  tail -10 /var/log/lfd.log

For Mail log:

Code:

  tail -10 /var/log/maillog

For Cron job logs:

Code:

  tail -10 /var/log/cron

How to edit php.ini and php-fpm configuration files ?

Centmin Mod install created command short cuts outlined here to allow you to quickly edit your /usr/local/lib/php.ini file and your /usr/local/etc/php-fpm.conf file. Full list of command shortcuts below:

• Edit php.ini = phpedit ( /usr/local/lib/php.ini )
• Edit my.cnf = mycnf ( /etc/my.cnf )
• Edit php-fpm.conf = fpmconf ( /usr/local/etc/php-fpm.conf )
• Edit nginx.conf = nginxconf ( /usr/local/nginx/conf/nginx.conf )
• Edit (nginx) virtual.conf = vhostconf - only edits /usr/local/nginx/conf/conf.d/virtual.conf not the additional vhost domain.com.conf files added later
• Edit (nginx) php.conf = phpinc ( /usr/local/nginx/conf/php.conf )
• Edit (nginx) drop.conf = dropinc ( /usr/local/nginx/conf/drop.conf )
• Edit (nginx) staticfiles.conf = statfilesinc ( /usr/local/nginx/conf/staticfiles.conf )
• nginx stop/start/restart = ngxstop/ngxstart/ngxrestart
• php-fpm stop/start/restart = fpmstop/fpmstart/fpmrestart
• mysql stop/start/restart = mysqlstop/mysqlstart/mysqlrestart
• nginx + php-fpm stop/start/restart = npstop/npstart/nprestart
• memcached stop/start/restart =memcachedstop/memcachedstart/memcachedrestart
• csf stop/start/restart = csfstop/csfstart/csfrestart

Troubleshooting Tools

However, there's many linux tools and scripts that can help you figure out what was causing the load issues and when.

Tools and commands you will want to read up on and learn for basic system admin tasks and troubleshooting.

• 20 Command Line Tools to Monitor Linux Performance
• 13 Linux Performance Monitoring Tools - Part 2
• 80 Linux Monitoring Tools for SysAdmins - Server Density Blog
• Amazing ! 25 Linux Performance Monitoring Tools
• 20 Linux System Monitoring Tools Every SysAdmin Should Know
• My mysqlmymonlite.sh script can help with that mysqlmymonlite.sh Addon | Centmin Mod Community README text file has instructions for setting up a cronjob to email you reports i.e. every 10/15min or every hour.

Notes:

• Centmin Mod already installed Glances tool. It can be invoked from SSH command glances or top2. Official Glances site at nicolargo.github.io/glances/ and documentation here.

However, Centmin Mod users are free to help each other out and ask questions or give answers on this community forum. My hopes are that this community forum evolves so that more veteran long time Centmin Mod users help new Centmin Mod users out

 

Also install these 2 tools

• Query Monitor — WordPress Plugins
• P3 (Plugin Performance Profiler) — WordPress Plugins