Archive for the ‘Wordpress’ Category

Briefly unavailable for scheduled maintenance. Fix WordPress after interrupted upgrade

Thursday, March 2nd, 2017


I've recenty tried Update my WordPress blog sites and being unattentive I've selected all the plugins possitble for Upgrade by checking the "Select All" check box on the Update dialogs and almost automatically int he hurry pressing Update button however out of a sudden I've realized I could screw up my websites brutally as some of the plugins to upgraded might be lacking 100% compitability with their prior versions.

I've made a messes out of my blog many times during upgrades because of choosing to upgrade the wrong not 100% compatible plugins and I know well how painful and hard to track it could be a misbehaving incompatible plugin or how ot could cause a severe sluggishness to blog which automatically reflects on how well the website search engine ranked in Google / Yahoo / Bing indexed etc.

Thus as an almost unconcsious reaction to prevent myself the future troubles I've tried to cancel the update request in Firefox browser and trying to reload the Update page with a hope that I might be quick enough for the Apache / WP / MySQLbackend Update Update queries request to be delaying for processing but I was too slow and bang! I ended up with the following unpleasent message in my browser:

Briefly unavailable for scheduled maintenance.

As you could guess that message caused me quite a lot of worries at hand especially since I've already break up my sites many times by doing quick unmindful reactions and the fact that there is Google Adsense ads appearing which does give me some Return on Investment cents every now and then …

It took me few minutes of research online to find what really happened and how to fix / resolve the WebSites normal operations.

So what causes the Briefly unavailable for scheduled maintenance. appears ?

When WordPress does some of its integrated maintenance jobs a plugin enable / disable or any task that has to modify crucial configurations inside the database WordPress does disable access to all end clients to itself in order to protect its sensitive data to appear to browser requestors as showing some unexpected information to end client browser could be later used by crackers / hackers or a possibly open a security hole for an attacker.

The message is wordpress generated notice and it is pretty normal for the end user to see it during the WP site installation update depending on how many plugins are installed and loaded to the site and how long it will take for the backend Linux / Windows server to fetch the archived .zips of plugins and substitute with the new ones and update the files extracting them to wp-content/plugins and updating the respective required SQL database / tables it could be showing for end users from few secs to few minutes.

However under some circumstances on Browser request timeout to remote wordpress site due to a network connectivity issue or just a bad configuration of Apache for requests timeout (or a slow remote server Apache responce time due to server Hardware / Mem overload) or a stupid browser "Stop" / cancel request like in my case you end up with the Briefly unavailable for scheduled maintenance and you can can longer access the your Admin Panel.

The message is triggered by a WP craeted file .maintenance inside /var/www/blog-site/ e.g. WordPress PHP scripts does check for /var/www/blog-site/.maintenance
existence and if it is matched the WP scripts does generate the Briefly unavailble … message.

How to resolve the "Briefly unavailable for scheduled maintenance. Check back in a minute" WordPress error ?

As you might guess removing the maintenance "coming soon" like message in most of the cases comes to just deleting the .maintenance file, to do so:

1. Login to remote server via FTP or SFTP
2. Locate your WP website root folder that should be something like /var/www/blog-site/.maintenance and issue:
issue something like:

$ rm -rf /var/www/bog-site/.maintenance

Assuming that some plugin Update .zip extraction or SQL update query did not ended being half installed / executed that should solve the error.
To check whether all is back to normal just refresh your browser pointing to the "broken" site. If it appears well you can thank God for that 🙂
If not check the apache error logs and php error logs and see which of the php scripts is failing and then try to manually fetch and unzip the WP .zip package to wp-content/plugins folder and give it another try and if God bless so it will work as before 🙂

How to prevent your WP based business in future from such nasty errors using A Staging site (test) version of your blog ?

Just run a duplicate of your website under a separate folder on your hosting and do enable the same plugins as on the primary website and copy over the MySQL / PostgreSQL Database from your Live site to the Staging, then once it is enabled before doing any crucial WordPress version updates or Plugins Update always do try the Upgrade first on your Test Staging site. If it does execute fine there in most of the cases the result should be the same on the Production host and that could solve you effors and nerves of debugging a hard to get failure errors or faulty plugins without affecting what your End users see.

If you're not hosting the WordPress install under your own hosting like me you can always use some of the public available hostings like  BlueHost or WPEngine


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Apache Webserver disable hostnamelookups “HostnameLookups off” for minor performance increase

Friday, February 12th, 2016


If you don't much care about logging in logs from which domain / hostnames requests to webserver originate and you want to boost up the Apache Webserver performance a bit especially on a heavy loaded Websites, where no need for stuff like Webalizer, Awstats etc. , e.g. you're using GoogleAnalytics to already track requests (beware as sometimes GoogleAnalytics could be missing requests to your webserver, so having some kind of LogAnalyzer software on server is always a plus). But anyways accepting that many of us already trust GoogleAnalytitcs.

Then a great tuning option to use in default domain configuration or in multiple VirtualHosts config is:

HostnameLookups off

If you want to make the HostnameLookups off as a default behaviour to all your virtualhosts on  Debian / Ubuntu / CentOS / SuSE / RHEL distro virtualhosts add either to default config /etc/apache2/sites-enabled/000-default (on Deb based Linuxes) or (on RPM based ones), add directive to /etc/httpd/httpd.conf

For self-hosted websites (if run your own small hosting) or for a home situated webservers with up to 20-50 websites it is also a useful optimization tip to include in /etc/hosts file all the IPs of sites with respective domain names following the normal syntax of /etc/hosts, e.g. in my own /etc/hosts, I have stuff like:

pcfreak:~$ cat /etc/hosts localhost localhost.localdomain pcfreak new-pcfreak fw
# for wordpress plugins
# The following lines are desirable for IPv6 capable hosts

# … etc. put IPs and hostnames following above syntax

As you see from above commented section for wordpress plugins, I've included some common websites used by WordPress enabled plugins to prevent my own hosting server to query DNS server every time. The normal way the Linux / Unix works is it first checks in /etc/hosts and only if the hostname is not defined there then it queries the DNS caching server in my case this is a local DJBDNS cache server, however defining the hosts in /etc/hosts saves a lot of milisecons on every request and often if multiple hosts are defined could save (decrease site opening for end users) with seconds.

Well now use some website speed testing plugin like Yslow, Firebug Fiddler or HTTPWatch


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Change website .JS .PHP Python Perl CSS etc. file permissions recursively for Better Tightened Security on Linux Webhosting Servers

Friday, October 30th, 2015


It is a common security (breach) mistake that developers or a web design studio make with dedicated or shared hosted websites do to forget to set a nice restrictive file permissions.

This is so because most people (and especially nowdays) developers are not a security freaks and the important think for a programmer is to make the result running in shortest time without much caring on how secure that is.
Permissions issues are common among sites written in PHP / Perl / Python with some CSS and Javascript, but my observations are that JavaScript websites especially that are using some frameworks such as Zend / Smarty etc. and are using JQuery are the most susceptible to suffer from permission security holes such as the classic 777 file permissions, because of developers who’re overworking and pushed up for a deadlines to include new functionality on websites and thus often publish their experimental code on a Production systems without a serious testing by directly uploading the experimental code via FTP / WinSCP on Production system.

Such scenarios are very common for small and middle sized companies websites as well as many of the hobbyist developers websites running on ready CMS system platforms such as Joomla and WordPress.
I know pretty well from experience this is so. Often a lot of the servers where websites are hosted are just share-servers without a dedicated sysadmin and thus there are no routine security audits made on the server and the security permissions issue might lead to a serious website compromise by a cracker and make your website quickly be banned from Google / Yahoo / Ask Jeeves / Yandex and virtually most of Search Engines because of being marked as a spammer or hacked webiste inside some of the multiple website blacklists available nowdays.

Thus it is always a good idea to keep your server files (especially if you’re sysadmin) with restrictive permissions by making the files be owned by superuser (root) in order to prevent some XSS or vulnerable PHP / Python / Perl script to allow you to easily (inject) and overwrite code on your website.

1. Checking whether you have a all users read, write, executable permissions with find command

The first thing to do on your server to assure you don’t have a low security permissioend files is:

find /home/user/website -type f -perm 777 -print

You will get some file as an output like:


2. Change permissions recursively to read, write and exec for root and read for everybody and set all files to be owned by (root) superuser

Then to fix the messy permissions files a common recommended permissions is 744 (e.g. Read / Write and Execute permissions for everyone and only read permissions for All Users and All groups).
Lets say you want to make files permissions to 744 just for all JavaScript (JQuery) files for a website, here is how:

find . -iname ‘*.js’ -type f -print -exec chown root:root ‘{}’ \;
find . -iname ‘*.js’ -type f -print -exec chmod 744 ‘{}’ \;

First find makes all Javascript files be owned by root user / group and second one sets all files permissions to 744.

To make 744 all files on server (including JPEG / PNG Pictures) etc.:

find . -iname /home/users/website -type f -print -exec chown root:root ‘{}’ \;
find . -iname /home/users/website -type f -print -exec chmod 744 ‘{}’ \;

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WordPress Security: Fix WordPress wp-config.php improper permissions to protect your sites from Database password steal / Website deface

Thursday, March 12th, 2015

Keeping WordPress Site / Blog and related installed plugins up-to-date
is essential to prevent an attacker to hack into your Site / Database and deface your site, however if you're a company providing shell access from Cpanel / Plesk / Kloxo Panel to customers often customers are messing up permissions leaving important security credential files such as wp-config.php (which is storing user / pass credentials about connection to MySQL / PostgreSQL to have improper permissions and be world readable e.g. have permissions such as 666 or 777 while in reality the WordPress recommended permissions for wp-config.php is 600. I will skip here to explain in details difference between file permissions on Linux as this is already well described in any Linux book, however I just will recommend for any Share hosting Admin where Wordperss is hosted on Lighttpd / Apache Webserver + Some kind of backend database to be extra cautious.

Hence it is very useful to list all your WordPress sites on server wp-config.php permissions with find like this:


find /  -iname 'wp-config.php' -print1;


I find it a generally good practice to also automatically set all wp-config.php permissions to 600 (6= Read / Write  permissions only for File Owner  user 0 = No permissions for All groups, 0 = No Permissions for all non-owner users)

If find command output gives you some file permissions such as:

ls -al /var/www/wordpress-bak/wp-config.php
-rw-rw-rw- 1 www-data www-data 2654 jul 28  2009 wp-config.php


E.g. file permission has 666 permissions (Readable for all users), then it is wise to fix this with:

chmod 600 /var/www/wordpress-bak/wp-config.php

It is generally a very good practice to run also a chmod 600 to each and every found wp-config.php file on server:

find /  -iname 'wp-config.php' -print1 -exec chmod 600 '{}' \;

Above command will also print each file to whcih permission is set to Read / Write for Owner (this si done with -print1 option).

It is a good practice for shared hosting server to always configure a root cronjob to run above find chmod command at least once daily (whenever server hosts 50 – 100 wordpress+ more sites).

crontab -u root -l | { cat; echo “05 03 * * * find /  -iname 'wp-config.php' -print1 -exec chmod 600 '{}' \; } | crontab – 

If you don't have the 600 permissions set for all wp-config.php files this security "backdoor" can be used by any existing non-root user to be read and to break up (crack)  in your database and even when there are Deface bot-nets involved to deface all your hosted server wordpress sites.

One of my servers with wordpress has just recently suffered with this little but very important security hole due to a WordPress site directory backup  with improper permissions which allowed anyone to enter MySQL database, so I guess there are plenty of servers with this hidden vulnerability silently living.

Many thanks to my dear friend (Dimitar PaskalevNomen for sharing with me about this vulnerability! Very important note to make here is admins who are using some security enhancement modules such as SuPHP (which makes Apache webserver to run Separate Website instances with different user), should be careful with his set all wp-config.php modules to Owner, as it is possible the wp-config.php owner change to make customer WP based websites inaccessible.

Another good security measure to  protect your server WordPress based sites from malicious theme template injections (for both personal own hosted wordpress based blog / sites or a WordPress hosting company) is to install and activate WordPress Antivirus plugin.

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Remove URL from comments in WordPress Blogs and Websites to mitigate comment spam URLs in pages

Friday, February 20th, 2015

If you're running a WordPress blog or Website where you have enabled comments for a page and your article or page is well indexing in Google (receives a lot of visit / reads ) daily, your site posts (comments) section is surely to quickly fill in with a lot of "Thank you" and non-sense Spam comments containing an ugly link to an external SPAM or Phishing website.

Such URL links with non-sense message is a favourite way for SPAMmers to raise their website incoming (other website) "InLinks" and through that increase current Search Engine position. 

We all know a lot of comments SPAM is generally handled well by Akismet but unfortunately still many of such spam comments fail to be identified as Spam  because spam Bots (text-generator algorithms) becomes more and more sophisticated with time, also you can never stop paid a real-persons Marketers to spam you with a smart crafted messages to increase their site's SEO ).
In all those cases Akismet WP (Anti-Spam) plugin – which btw is among the first "must have"  WP extensions to install on a new blog / website will be not enough ..

To fight with worsening SEO because of spam URLs and to keep your site's SEO better (having a lot of links pointing to reported spam sites will reduce your overall SEO Index Rate) many WordPress based bloggers, choose to not use default WordPress Comments capabilities – e.g. use exnternal commenting systems such as Disqus – (Web Community of Communities), IntenseDebate, LiveFyre, Vicomi

However as Disqus and other 3rd party commenting systems are proprietary software (you don't have access to comments data as comments are kept on proprietary platform and shown from there), I don't personally recommend (or use) those ones, yes Disqus, Google+, Facebook and other comment external sources can have a positive impact on your SEO but that's temporary event and on the long run I think it is more advantageous to have comments with yourself.
A small note for people using Disqos and Facebook as comment platforms – (just imagine if Disqos or Facebook bankrupts in future, where your comments will be? 🙂 )

So assuming that you're a novice blogger and I succeeded convincing you to stick to standard (embedded) WordPress Comment System once your site becomes famous you will start getting severe amount of comment spam. There is plenty of articles already written on how to remove URL comment form spam in WordPress but many of the guides online are old or obsolete so in this article I will do a short evaluation on few things I tried to remove comment spam and how I finally managed to disable URL link spam to appear on site.

1. Hide Comment Author Link (Hide-wp-comment-author-link)

This plugin is the best one I found and I started using it since yesterday, I warmly recommend this plugin because its very easy, Download, Unzip, Activate and there you're anything typed in URL field will no longer appear in Posts (note that the URL field will stay so if you want to keep track on person's input URL you can get still see it in Wp-Admin). I'm using default WordPress WRC (Kubrick), but I guess in most newer wordpress plugins is supposed to work. If you test it on another theme please drop a comment to inform whether works for you.  Hide Comment Author Link works on current latest Wordpress 4.1 websites.

A similar plugin to hide-wp-author-link that works and you can use is  Hide-n-Disable-comment-url-field, I tested this one but for some reason I couldn't make it work.

Whatever I type in Website field in above form, this is wiped out of comment once submitted 🙂

2. Disable hide Comment URL (disable-hide-comment-url)

I've seen reports disable-hide-comment-url works on WordPress 3.9.1, but it didn't worked for me, also the plugin is old and seems no longer maintaned (its last update was 3.5 years ago), if it works for you please please drop in comment your WP version, on WP 4.1 it is not working.


3. WordPress Anti-Spam plugin

WordPress Anti-Spam plugin is a very useful addition plugin to install next to Akismet. The plugin is great if you don't want to remove commenter URL to show in the post but want to cut a lot of the annoying Spam Robots crawling ur site.

Anti-spam plugin blocks spam in comments automatically, invisibly for users and for admins.

  • no captcha, because spam is not users' problem
  • no moderation queues, because spam is not administrators' problem
  • no options, because it is great to forget about spam completely

Plugin is easy to use: just install it and it just works.

Anti bot works fine on WP 4.1

4. Stop Spam Comments

Stop Spam Comments is:

  • Dead simple: no setup required, just activate it and enjoy your spam-free website.
  • Lightweight: no additional database queries, it doesn't add script files or other assets in your theme. This means your website performance will not be affected and your server will thank you.
  • Invisible by design: no captchas, no tricky questions or any other user interaction required at all.

Stop Spam Comments works fine on WP 4.1.

I've mentioned few of the plugins which can help you solve the problem, but as there are a lot of anti-spam URL plugins available for WP its up to you to test and see what fits you best. If you know or use some other method to protect yourself from Comment Url Spam to share it please.

Import thing to note is it usually a bad idea to mix up different anti-spam plugins so don't enable both Stop Spam Comments and WordPress Anti Spam plugin.

5. Comment Form Remove Url field Manually 

This (Liberian) South) African blog describes a way how to remove URL field URL manually

In short to Remove Url Comment Field manually either edit function.php (if you have Shell SSH access) or if not do it via Wp-Admin web interface:

WordPress admin page –> Appearance –> Editor

Paste at the end of file following PHP code:


add_filter('comment_form_default_fields', 'remove_url');
 function remove_url($fields)
 return $fields;

Now to make changes effect, Restart Apache / Nginx Webserver and clean any cache if you're using a plugin like W3 Total Cache plugin etc.

Other good posts describing some manual and embedded WordPress ways to reduce / stop comment spam is here and here, however as it comes to my blog, none of the described manual (code hack) ways I found worked on WordPress v. 4.1.
Thus I personally stuck to using Hide and Disable Comment URL plugin  to get rid of comment website URL.

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WordPress Plugins to monitor and debug WP enabled plugins – Find Errors / Warnings and Remove WP problematic plugins slowing down your Website (blog) database

Thursday, February 19th, 2015


Recent days, I'm spending a lot of time again trying to optimize my wordpress blog. Optimizing WP for better efficiency is becoming harder and harder task day by day as the website file content data is growing along with SQL databases. Moreover situation gets even worse because the number of plugins enabled on my blog is incrementally growing with time because, there is more and more goodies I'd like to add.
Optimizing WordPress to run for Speed on a server is a whole a lot of art and its a small universe in itself, because as of time of writting this post the count (number) of WordPress available PLUGINS is 36,197 ! 

1. Manually Tracking WordPress  Plugins causing Slow SQL Queries (MySQL bottleneck) issues directly using console / SSH

Because of its open source development and its nice modular design wordpress has turned into a standard for building small, middle sized and large websites (some WordPress based blogs and sites have from 50 000 to 100 000 unique pages!). My blog is still a small WordPress site with only 1676 posts, so I still haven't reached the high volume traffic optimization requirements but still even though I have a relatively good server hardware  8GB RAM / (2×2.70 Ghz Intel CPU) / 500 GB (7400 RPM HDD) at times I see Apache Webservers is unable to properly serve coming requests because of MySQL database (LEFT JOIN) requests being slow to serve (taking up to few seconds to complete) and creating a MySQL table lock, putting all the rest SQL queries to stay in a long unserved queues line, I've realized about this performance issue by using a a mysql cli (command) client and few commands and console command (tool) called mytop (also known as mtop). MyTop refreshes every 3 seconds, so the slow query will immediately stay on screen to view moer info about it press "f" and type the  in query ID.



Finally it is very useful to run  for a while MySQL server logging to /var/log/mysql/slow-query.log:
Slow query is enabled (on my Debian 7 Wheezy host) by adding to /etc/mysql/my.cnf
after conf section


vim /etc/mysql/my.cnf
# * Logging and Replication
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
# Here you can see queries with especially long duration




slow_query_log = 1
slow_query_log_file = /var/log/mysql/slow-query.log
long_query_time = 2


And then to make new mysql configuration load restarted mysql server:


debian-server:~# /etc/init.d/mysql restart
Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld ..
Checking for tables which need an upgrade, are corrupt or were
not closed cleanly..


Leaving mysql-slow.log to be enabled for 30 minutes to an 1 hrs is a good time to track most problematic slow queries and based on this queries, I took parts of  SQL UPDATE / SELECT / INSERT etc. Db queries which was problematic and grepped throughout /var/www/blog/wp-content/plugin files in order to determine which WordPress Plugin is triggering the slow query, causing blog to hang when too many clients try to see it in browser.

My main problematic SQL query having long execution time  (about 2 to 3 seconds!!!) most commonly occuring in slow-query.log was:


SELECT DISTINCT post_title, ID, post_type, post_name FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE (post_type='page' OR (wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN(11))) AND post_status = 'publish' AND LENGTH(post_title)>=5 ORDER BY LENGTH(post_title) ASC LIMIT 500

Because above query uses SQL Column names and Tables which are not hard coded in PHP code, to find out which plugins is most probably to launch this complex LEFT JOIN query, I used a quick bash one-liner:


# cd /var/www/blog/wp-content/plugins


# for i in $(grep -rli 'SELECT DISTINCT' *); do grep -rli 'LEFT JOIN' $i; done 


I wanted to put less load on CPU during grep so looked for string only in .PHP extensioned files with:


 # for i in $(find . -iname '*.php' -exec grep -rli 'SELECT DISTINCT' '{}' \;); do grep -rli 'LEFT JOIN' $i; done

As you can see the complex query is being called from PHP file belonging to one of 3 plugins

  • SEO Automatic Links – this is SEO Smart Links WP plugin (Does internal bliog interlinking in order to boast SEA)
  • WP PostViews – WordPress Post Views plugin (Which allows me to show how many times an article was read in WP Widget menu)
  • Yet Another Related Posts – Which is WP plugin I installed / enabled to show Related posts down on each blog post

2. Basic way to optimize MySQL slow queries (EXPLAIN / SHOW CREATE TABLE)

Now as I have a basic clue on plugins locking my Database, I disabled them one by one while keeping enabled mysql slow query log and viewing queries in mytop and I figure out that actually all of the plugins were causing a short time overheat (lock) on server Database because of LEFT JOINs. Though I really like what this plugins are doing, as they boast SEO and attract prefer to disable them for now and have my blog all the time responsible light fast instead of having a little bit better Search Engine Optimization (Ranking) and loosing many of my visitors because they're annoyed to wait until my articles open

Before disabling I tried to optimize the queries using MySQL EXPLAIN command + SHOW CREATE TABLE (2 commands often used to debug slow SQL queries and find out whether a Column needs to have added INDEX-ing to boast MySQL query).

Just in case if you decide to give them a try here is example on how they're used to debug problematic SQL query:

  1. mysql> explain SELECT DISTINCT post_title, ID, post_type, post_name
  2.     -> FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta
  3.     -> ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships
  4.     -> ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy
  5.     -> ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id)
  6.     -> WHERE (post_type='page'
  7.     -> OR (wp_term_taxonomy.taxonomy = 'category'
  8.     -> AND wp_term_taxonomy.term_id IN(11,15,17)))
  9.     -> AND post_status = 'publish'
  10.     -> AND LENGTH(post_title)>=5
  11.     -> ORDER BY LENGTH(post_title) ASC
  12.     -> LIMIT 500;
  13. +—-+————-+———————–+——–+——————+———+———+———————————————+——+———————————————-+
  14. | id | select_type | table                 | type   | possible_keys    | key     | key_len | ref                                         | rows | Extra                                        |
  15. +—-+————-+———————–+——–+——————+———+———+———————————————+——+———————————————-+
  16. |  1 | SIMPLE      | wposts                | ALL    | type_status_date | NULL    | NULL    | NULL                                        | 1715 | Using where; Using temporary; Using filesort |
  17. |  1 | SIMPLE      | wpostmeta             | ref    | post_id          | post_id | 8       | blog.wposts.ID                              |   11 | Using index; Distinct                        |
  18. |  1 | SIMPLE      | wp_term_relationships | ref    | PRIMARY          | PRIMARY | 8       | blog.wposts.ID                              |   19 | Using index; Distinct                        |
  19. |  1 | SIMPLE      | wp_term_taxonomy      | eq_ref | PRIMARY          | PRIMARY | 8       | blog.wp_term_relationships.term_taxonomy_id |    1 | Using where; Distinct                        |
  20. +—-+————-+———————–+——–+——————+———+———+———————————————+——+———————————————-+
  21. 4 rows in set (0.02 sec)
  23. mysql>



  1. mysql> show create table wp_posts;
  2. +———-+————————–+
  3. | Table    | Create Table                                                                                                                                                                                                                                                                                                                                                                                                                                 |
  4. +———-+————————–+
  5. | wp_posts | CREATE TABLE `wp_posts` (
  6.   `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  7.   `post_author` bigint(20) unsigned NOT NULL DEFAULT '0',
  8.   `post_date` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  9.   `post_date_gmt` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  10.   `post_content` longtext NOT NULL,
  11.   `post_title` text NOT NULL,
  12.   `post_excerpt` text NOT NULL,
  13.   `post_status` varchar(20) NOT NULL DEFAULT 'publish',
  14.   `comment_status` varchar(20) NOT NULL DEFAULT 'open',
  15.   `ping_status` varchar(20) NOT NULL DEFAULT 'open',
  16.   `post_password` varchar(20) NOT NULL DEFAULT '',
  17.   `post_name` varchar(200) NOT NULL DEFAULT '',
  18.   `to_ping` text NOT NULL,
  19.   `pinged` text NOT NULL,
  20.   `post_modified` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  21.   `post_modified_gmt` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  22.   `post_content_filtered` longtext NOT NULL,
  23.   `post_parent` bigint(20) unsigned NOT NULL DEFAULT '0',
  24.   `guid` varchar(255) NOT NULL DEFAULT '',
  25.   `menu_order` int(11) NOT NULL DEFAULT '0',
  26.   `post_type` varchar(20) NOT NULL DEFAULT 'post',
  27.   `post_mime_type` varchar(100) NOT NULL DEFAULT '',
  28.   `comment_count` bigint(20) NOT NULL DEFAULT '0',
  29.   PRIMARY KEY (`ID`),
  30.   KEY `post_name` (`post_name`),
  31.   KEY `type_status_date` (`post_type`,`post_status`,`post_date`,`ID`),
  32.   KEY `post_parent` (`post_parent`),
  33.   KEY `post_author` (`post_author`),
  34.   FULLTEXT KEY `post_related` (`post_title`,`post_content`)
  36. +———-+———————-+
  37. 1 row in set (0.00 sec)
  39. mysql>

By the way above output is a paste from the the new PasteBin Open Source (Stikked powered) service I started on – ( 🙂

Before I took final decision to disable slow WP plugins, I've experimented a bit trying to add INDEX to Table Column (wposts) in hope that this would speed up SQL queries with:




But this didn't improve query speed even on the contrary it make execution time worse.

3. Tracking WordPress Plugin PHP Code Execution time and Plugins causing Slow SQL Queries (MySQL bottleneck) issues through WP itself

Well fine, I'm running my own hosted Blog and WordPress sites, but for people who have wordpress sites on shared hosting, there is usually no SSH (Terminal) Access to server, those people will be happy to hear there are 2 Free easy installable WordPress plugins which can be used to Debug Slow WordPress Plugins SQL Queries as well as plugin to Track which plugin takes most time to execute, this are:


a) P3 Plugin Performance Profiler  

runs a scan over your site to determine what resources your plugins are using, and when, during a standard page request. P3 PPP Can even create reports in a beatiful Excel like Pie chart sheet.


Another useful thing to see with P3 PPP is Detailed Timeline it shows when the plugins are being loaded during new page request so you can see if there is a certain sequence in time when a plugin slows down the website.


The pictures says it all as P3 PPP is Godaddy's work, congrats to GoDaddy, they've done great job.


b) WordPress memory Viewer WP plugins

Is useful to check how much memory each of WordPress plugin is taking on user (visitor) request.
Memory Viewer is allows you to view WordPress’ memory utilization at several hooks during WordPress’ execution. It also shows a summary of MySQL Queries that have ran as well as CPU time.
To use it download it to plugins/ folder as usual enable it from:

Installed Plugins -> (Inactive) -> Memory Viewer (Enable)

To see statistics from Memory Viewer open any post from your blog website and scroll down to the bottom you will notice the statistics, showing up there, like on below screenshot.


Though WP Memory Viewer is said to work only up to WP version 3.2.1, I've tested it and it works fine on my latest stable WordPress 4.1 based blog.

c) WordPress Query Monitor


Query Monitor is a debugging plugin for anyone developing with WordPress but also very helpful for anyone who want to track issues with plugins who use the database unefficient.
It has some advanced features not available in other debugging plugins, including automatic AJAX debugging and the ability to narrow down things by plugin or theme.
You can view plenty of precious statistics on how enabled plugins query the database server, here is a short overview on its Database Queries capabilities:

  • Shows all database queries performed on the current page
  • Shows affected rows and time for all queries
  • Show notifications for slow queries and queries with errors
  • Filter queries by query type (SELECT, UPDATE, DELETE, etc)
  • Filter queries by component (WordPress core, Plugin X, Plugin Y, theme)
  • Filter queries by calling function
  • View aggregate query information grouped by component, calling function, and type
  • Super advanced: Supports multiple instances of wpdb on one page
  • Once enabled from Plugins you will see it appear as a new menu on bottom Admin raw.

An important note to make here is latest Query Monitor extension fails when loaded on current latest Wordpress 4.1, to use it you will have to download and useolder Query Monitor plugin version 2.6.8 you can download it from here

d) Debug Bar

If you want you want a Memory Viewer like plugin for more complex used components memory debugging, reporting if (WP_DEBUG is set in wp-config.php) also check out Debug Bar .
For me Debug Bar was very useful because it show me depreciated functions some plugins used, so I substituted the obsoleted function with new one.



4. Server Hardware hungry (slow) WordPress plugins that you better not use

While spending time to Google for some fixes to WP slow query plugins – I've stumbled upon this post giving a good list with WordPress Plugins better off not to use because they will slow down your site
This is a publicly well known list of WP plugins every WordPress based site adminstrator should avoid, but until today I didn't know so my assumption is you don't know either ..

Below plugins are extremely database intensive mentioned in article that we should better (in all cases!) avoid:

  • Dynamic Related Posts
  • SEO Auto Links & Related Posts
  • Yet Another Related Posts Plugin
  • Similar Posts
  • Contextual Related Posts
  • Broken Link Checker — Overwhelms even our robust caching layer with an inordinate amount of HTTP requests.
  • MyReviewPlugin — Slams the database with a fairly significant amount of writes.
  • LinkMan — Much like the MyReviewPlugin above, LinkMan utilizes an unscalable amount of database writes.
  • Fuzzy SEO Booster — Causes MySQL issues as a site becomes more popular.
  • WP PostViews — Inefficiently writes to the database on every page load. To track traffic in a more scalable manner, both the stats module in Automattic’s Jetpack plugin and Google Analytics work wonderfully.
  • Tweet Blender — Does not play nicely with our caching layer and can cause increased server load.

A good Complete list of known WordPress slow plugins that will hammer down your wordpress performance is here

There are few alternatives to this plugins and when I have some free time I will download and test their alternatives but for now I plan the plugins to stay disabled.

For the absolute WP Performance Optimization Freaks, its good to check out the native way to Debug a wordpress installation through using few embedded


define('WP_DEBUG', true);
define('WP_DEBUG', false);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
define('SAVEQUERIES', true);


An article describing how you can use native WP debug variables is here

Happy Optimizing  ! 🙂

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How to get a list and Backup (Save Enabled Plugins) / Restore Enabled (Active) plugins in WordPress site with SQL query

Wednesday, January 14th, 2015


Getting a snapshot of all active plugins and keeping it for future in case if you install some broken plugin and you have to renable all enabled plugins from scratch is precious thing in WordPress.

… It is really annoying when you decide to try to enable few new plugins and out of a sudden your WordPress site / blog starts hanging (when accessed in browser)…

To fix it you have to Disable All Plugins and Re-enable all that used to work. However if you don't keep a copy of the plugins which were previously working and you're like me and have 109 plugins installed of which only 50 are in (Active) state / used. It could take you a day or two until you come up with a similar list to the ones you previously used … Thanksfully there is some prevention you can take by dumping a list of all plugins that are currently active and in later time only enable those in the list.


# mysql -u root -p
Enter password:

mysql> USE blog_db;

Here is the output I get in the moment:

mysql> DESCRIBE wp_options;
| Field        | Type                | Null | Key | Default | Extra          |
| option_id    | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment |
| option_name  | varchar(64)         | NO   | UNI |         |                |
| option_value | longtext            | NO   |     | NULL    |                |
| autoload     | varchar(20)         | NO   |     | yes     |                |


mysql> SELECT * FROM wp_options WHERE option_name = 'active_plugins';

|        38 | active_plugins | a:50:{i:0;s:45:"add-to-any-subscribe/add-to-any-subscribe.php";i:1;s:19:"akismet/akismet.php";i:2;s:43:"all-in-one-seo-pack/all_in_one_seo_pack.php";i:3;s:66:"ambrosite-nextprevious-post-link-plus/ambrosite-post-link-plus.php";i:4;s:49:"automatic-tag-selector/automatic-tag-selector.php";i:5;s:27:"autoptimize/autoptimize.php";i:6;s:35:"bm-custom-login/bm-custom-login.php";i:7;s:45:"ckeditor-for-wordpress/ckeditor_wordpress.php";i:8;s:47:"comment-info-detector/comment-info-detector.php";i:9;s:27:"comments-statistics/dcs.php";i:10;s:31:"cyr2lat-slugs/cyr2lat-slugs.php";i:11;s:49:"delete-duplicate-posts/delete-duplicate-posts.php";i:12;s:45:"ewww-image-optimizer/ewww-image-optimizer.php";i:13;s:34:"feedburner-plugin/fdfeedburner.php";i:14;s:39:"feedburner-widget/widget-feedburner.php";i:15;s:63:"feedburner_feedsmith_plugin_2.3/FeedBurner_FeedSmith_Plugin.php";i:16;s:21:"feedlist/feedlist.php";i:17;s:39:"force-publish-schedule/forcepublish.php";i:18;s:50:"google-analytics-for-wordpress/googleanalytics.php";i:19;s:81:"google-sitemap-generator-ultimate-tag-warrior-tags-addon/UTWgoogleSitemaps2_1.php";i:20;s:36:"google-sitemap-generator/sitemap.php";i:21;s:24:"headspace2/headspace.php";i:22;s:29:"my-link-order/mylinkorder.php";i:23;s:27:"php-code-widget/execphp.php";i:24;s:43:"post-plugin-library/post-plugin-library.php";i:25;s:35:"post-to-twitter/post-to-twitter.php";i:26;s:28:"profile-pics/profile-pic.php";i:27;s:27:"redirection/redirection.php";i:28;s:42:"scripts-to-footerphp/scripts-to-footer.php";i:29;s:29:"sem-dofollow/sem-dofollow.php";i:30;s:33:"seo-automatic-links/seo-links.php";i:31;s:23:"seo-slugs/seo-slugs.php";i:32;s:41:"seo-super-comments/seo-super-comments.php";i:33;s:31:"similar-posts/similar-posts.php";i:34;s:21:"sociable/sociable.php";i:35;s:44:"strictly-autotags/strictlyautotags.class.php";i:36;s:16:"text-control.php";i:37;s:19:"tidy-up/tidy_up.php";i:38;s:37:"tinymce-advanced/tinymce-advanced.php";i:39;s:33:"tweet-old-post/tweet-old-post.php";i:40;s:33:"w3-total-cache/w3-total-cache.php";i:41;s:44:"widget-settings-importexport/widget-data.php";i:42;s:54:"wordpress-23-related-posts-plugin/wp_related_posts.php";i:43;s:23:"wp-minify/wp-minify.php";i:44;s:27:"wp-optimize/wp-optimize.php";i:45;s:33:"wp-post-to-pdf/wp-post-to-pdf.php";i:46;s:29:"wp-postviews/wp-postviews.php";i:47;s:55:"wp-simple-paypal-donation/wp-simple-paypal-donation.php";i:48;s:46:"wp-social-seo-booster/wpsocial-seo-booster.php";i:49;s:31:"wptouch-pro-3/wptouch-pro-3.php";} | yes      |

Copy and paste this CVS format data to a text file or a Word document for later reference ..

To restore back to normal only active WordPress plugins, first launch following SQL query to disable all enabled wordpress plugins:

UPDATE wp_options SET option_value = 'a:0:{}' WHERE option_name = 'active_plugins';

To restore above "backupped" list of active WP plugins you have to copy paste the saved content and paste it into above UPDATE query substituting option_value=' ' with the backupped string.

P.S. – This query should work on WordPress 3.x on older wordpress ver 2.x use instead:

UPDATE wp_options SET option_value = ' ' WHERE option_name = 'active_plugins';

Because pasting the backupped Active plugins list CSV is a messy and unreadable from command line it is recommended for clarity to use PHPMyAdmin frontend (whenever it is available) on server. This little hint is a real time-saver and saves a lot of headaches. Before proceeding to any Db UPDATE SQL queries always backup your Blog database, with time structure of WordPress data changes!, so in future releases this method might not be working, however if it helped you and works on your version please drop a comment with WordPress version on which this helped you.

Enjoy! 🙂


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Optimize WordPress Pictures with EWWW Image Optimizer, Async JS and CSS and Autoptimize for better Search Engine Ranking

Tuesday, December 9th, 2014



While optimizing picture performance with console tools optipng, jpegoptin, jpegtran, pngcrush (could save you a lot of server space and make pictures downloads faster (and hence increase your website responsiveness and SEO – check out), still for Blogs and WebSites based on WordPress its not worthy to loose time with console acrobatics but simply use EWWW Image Optimizer to Optimize all old or new uploaded Images.

To work EWWW Image Optimizer needs jpegtran, optipng, pngout and gifsicle to be installed on the Linux / BSD server. EWWW Image Optimizer can load the command line tools also from a Cloud, if a cloud service is running on the server. Once installed the plugin does scan all the imported WordPress Media files and can be run to optimize picture files on present blog psot / pages.

EWWW Image Opitimizer plugin does a good job in reducing file size on  NextGEN, GRAND FlAGallery galleries.


Here is how EWWW Image Optimizer works taken from plugin's website:
How are JPGs optimized?

Lossless optimization is done with the command jpegtran -copy all -optimize -progressive -outfile optimized-file original-file. Optionally, the -copy switch gets the 'none' parameter if you choose to strip metadata from your JPGs on the options page. Lossy optimization is done using the outstanding JPEGmini utility.
It is better if the server has not the jpegtran, pngout, gifsicle utilities installed as the plugin provides an uptodate static compiled Linux binaries.

How are PNGs optimized?

There are three parts (and all are optional). First, using the command pngquant original-file, then using the commands pngout-static -s2 original-file and optipng -o2 original-file. You can adjust the optimization levels for both tools on the settings page. Optipng is an automated derivative of pngcrush, which is another widely used png optimization utility.

How are GIFs optimized?

Using the command gifsicle -b -O3 –careful original file. This is particularly useful for animated GIFs, and can also streamline your color palette. That said, if your GIF is not animated, you should strongly consider converting it to a PNG. PNG files are almost always smaller, they just don't do animations. The following command would do this for you on a Linux system with imagemagickconvert somefile.gif somefile.png


Some othe plugins that could strenghten your WordPress Search Engine Optimization ranking worthy to check are:

  • Async JS and CSS

Most importantly plugin solves "Render-blocking JavaScript and CSS" warning shown during site audit with  Google Developers PageSpeed InsightBy the way Google PageSpeed Insight is a precious tool so I recommend you check if you already haven't, Google's suggestions could often double or triple daily site visitors 

What Async JS and CSS does is:

Converts render-blocking CSS and JS files into NON-render-blocking, improving performance of web page


The plugin makes ALL scripts loaded by other plugins to be loaded in asynchronous. All CSS files will be inserted inline into the document code or moved from the document beginning to the end, just before closing BODY tag (or just where you placed wp_foot() function). There are various methods to do that via plugin configuration page.

  • Autoptimize





Autoptimize speeds up your website and helps you save bandwidth by aggregating and minimizing JS, CSS and HTML.

What does the plugin do to help speed up site?

It concatenates all scripts and styles, minifies and compresses them, adds expires headers, caches them, and moves styles to the page head, and scripts to the footer. It also minifies the HTML code itself, making your page really lightweight. Autoptimize is very much like WP Mnify (CSS / JS) minifaction WP plugin. The only difference and reason why you might want to use WP Mnify is it does HTML minification – something that WP Minify does not. Both plugins play nice together the only thing to be careful is not to configure CSS / JS minification in both Autoptimize and WP Minifyas this might slower instead of fasten the WP site.

A great bunch of other useful WP plugins to make a WordPress Blog friendly to Search Engines is here.

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How to determine WordPress blogs with most spam on multiple blog hosting server

Thursday, November 27th, 2014

If you're a hosting company that is hosts Joomla / WordPress / ModX websites (each) on separate servers and thus you end up with servers hosting multiple WordPress customer Blogs only, lets say (100+ WP blogs per host) soon your MySQL blogs databases will be full (overfilled) with spam comments. Blogs with multitude of spam comments reduces the WordPress site attractiveness, takes useless disk space, makes wp databases hard to backup and slowing drastically the SQL server.

As our duty as system administrators is to keep the servers optimized (improve performance) and prevent spam-bots to hammer your Linux servers, its is always a good idea to keep an eye on which hosted blogs attract more spammers and cause server overheads and bad hardware optimization.

WordPress blogs keeps logged comments under database_name.wp_comments  (table) thus the quickest way to find out blogs with largest comments tables is to use Linux's find command and print out only comments tables larger than set size.

Here is how:

find /var/lib/mysql/ -type f -size +1024k -name "*_comments.MYD" -exec ls -lh {} ; | awk '{ print $9 ": " $5 }'

/var/lib/mysql/funny-blog/wp_comments.MYD: 15,7M
/var/lib/mysql/wordblogger/wp_comments.MYD: 5,3M
/var/lib/mysql/loveblog/wp_comments.MYD: 50,5M

A comments database of 1MB means about at least 500+ comments, thus the blog loveblog's wp_comments.MYD = 50,5 Mbs contains probably about 10000! comments and should be definitely checked in a browser, if its overfilled with spam because of bad anti-spam policy or missing currently best wordpress spam catcher plugin Akismet. In cases of lack of client to protect his spam you can write quickly a script to auto mail him and ask him kindly to check / fix his blog spam.
In some cases it is useful to write a few liners bash script to automatically disable users with extraordinary blog spam comments databases (quickest way to do it is to move users blog data under quarantine directory and adding a Blog Suspended static html webpage with text like "Please contact support for more info".

1024k find arguments is 1MB, on a big hosted blogs this might be low and you might want to use (100Mb) = 102400kbytes.
You should note that *_comments.MYD in above find cmd is because though standardly wordpress sets wp_ as a prefix to its created skele table structures it is not always the case. 

In above command example find looks for spam comments in /var/lib/mysql (because this is a Debian Linux server), however on other MySQL custom installs, it might be in another dir i.e. /usr/local/mysql/data etc.

It is useful to set the wp_comments statistics output to execute at least once a day as a cronjob:

crontab -u root -e 00 24 * * * /usr/sbin/

vim /usr/

Set a script like:

find /var/lib/mysql/ -type f -size +1024k -name "*_comments.MYD" -exec ls -lh {} ; | awk '{ print $9 ": " $5 }' | tee -a /var/log/blogs_with_most_spam_comments.log

Though above commands is to run on GNU / Linux, for Windows servers based hosting you can  install GNUWin tools and adapt above cmd using windows standard commands or PowerShell to do the same.
Finally you can might want to use some other SQL script to clear blogs with enormously large tables from spam or clear all unapproved spam comments

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