Fumiki Takahashi

TAROSKY INC.

Kunoichi INC

<p>Have you ever seen an error log like the one below?</p>
<blockquote>
<p>PHP Fatal error: Allowed memory size of xxxxxx bytes exhausted (tried to allocate xxx bytes) in /var/www/wordpress/wp-includes/wp-db.php on line 2007</p>
</blockquote>
<p>This means that <a href="https://www.php.net/manual/en/ini.core.php#ini.memory-limit" rel="nofollow ugc">PHP memory limit</a> is exhausted while retrieving data from a database. In any case, this happens when your site has big data and makes insane loops inside.</p>
<p>But we want to know that <strong>which plugin tried to retrieve data?</strong></p>
<p>Hagakure adds extra information to error.log file when <code>wp-db.php</code> causes memory limit error:</p>
<pre>[08-May-2019 10:28:37 UTC] wpdb Error Backtrace:
#1      Kunoichi\Hagakure\DbLogger->filter_query()      /app/public/wp-includes/class-wp-hook.php       Line 286
#2      WP_Hook->apply_filters()        /app/public/wp-includes/plugin.php      Line 208
#3      apply_filters   /app/public/wp-includes/wp-db.php       Line 1871
#4      wpdb->query()   /app/public/wp-includes/wp-db.php       Line 2579
#5      wpdb->get_results()     /app/public/wp-includes/class-wp-query.php      Line 2979
#6      WP_Query->get_posts()   /app/public/wp-includes/class-wp-query.php      Line 3387
#7      WP_Query->query()       /app/public/wp-includes/post.php        Line 1961
#8      get_posts       /app/public/wp-content/plugins/hagakure/hagakure.php    Line 34
#9      {closure}       /app/public/wp-includes/class-wp-hook.php       Line 286
#10     WP_Hook->apply_filters()        /app/public/wp-includes/class-wp-hook.php       Line 310
#11     WP_Hook->do_action()    /app/public/wp-includes/plugin.php      Line 465
#12     do_action       /app/public/wp-includes/template-loader.php     Line 13
#13     require_once    /app/public/wp-blog-header.php  Line 19
#14     require /app/public/index.php   Line 17
#15     URI: /?p=1</pre>
<p>This log will always follow the memory limit Fatal Error by <code>wp-db.php</code>. Now you can find <code>#8</code> calls <code>get_posts</code> repeatedly.</p>
<p>We recommend watching logs with notification services like <a href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/WhatIsCloudWatchLogs.html" rel="nofollow ugc">CloudWatch Logs</a>.<br />
This error occurs in the productional environment, and you may not have a chance to see it occurs.<br />
We use Hagakure with our <a href="https://hosting.kunoichiwp.com/" rel="nofollow ugc">hosting service</a>, please look forward to seeing <a href="https://kunoichiwp.com/blog" rel="nofollow ugc">our blog published</a> and describing the integration!</p>
<p>This plugin also adds debug backtrace to error logs. To modify the error level to a detailed backtrace, define the constant in <code>wp-config.php</code> or somewhere else:</p>
<pre>define( 'HAGAKURE_ERROR_LEVEL', E_NOTICE | E_USER_WARNING | E_WARNING | E_USER_ERROR );</pre>
<p>Besides that, if <code>SAVEQUERIES</code> is set <code>true</code>, the slow query log will be logged with PHP debug backtrace. This helps you to debug.</p>
<h3>Acknowledgements</h3>
<p>The base text for dummy content is “Three Ghost Story” by Charles Dickens. The text file is modified the one of <a href="https://www.gutenberg.org/ebooks/1289" rel="nofollow ugc">Project Gutenberg</a>.</p>


Hagakure – Yet Another Error Reporter

This plugin makes it easy to find the root cause of PHP Fatal error: Allowed memory size of xxxxxx bytes exhausted error. AWESOME.


Great

Looks good

A WordPress plugin to clarify meaningless errors like "Allowed memory size of xxxxxxxx bytes exhausted".

Code Machine

<h4>Purpose</h4>
<p>Detect WordPress Plugins ‘Fatal Errors’ that might block/prevent site admins from accessing WordPress admin interface in order to deactivate the Plugin that caused the issue! UBP then report/notify (sedning email) site admin with a secure link that valid for 24 hours from which site admin can deactivate the target Plugin by simply clicking the link!</p>
<p>For development state and issue tracking follow the Plugin on <a href="https://github.com/xpointer/ubp" rel="nofollow ugc">GitHub Respository</a></p>
<h4>Mechanism</h4>
<p>The mechanism of the Plugin is to always put itself as the first Plugin to be executed by WordPress Plugins system! The Plugin then just stay away and never get itself involved until the execution of all the other scripts is then terminated! UBP Plugin role is comes when the script is terminated. It then check if the script is terminated with error. If the script if terminated with error UBP send admin mail with backup link that has a secure key by which UBP give the link owner the permission to disable the target Plugin.</p>
<h4>Advantages</h4>
<ul>
<li>There is no need to access throught FTP to force WordPress deactivate the Plugin. You can always use this Plugin to deactivate the target Plugin only with the link sent with the mail.</li>
<li>Load minimum codes/scripts that required only to get involved (listen to errors). Load code required to functional only when error detcted.</li>
</ul>
<h4>Notes</h4>
<ul>
<li>Whenever you active or deactive a Plugin, UBP will always put itself as the first Plugin in WordPress active Plugins queue.</li>
<li>The Plugin won’t install itself while the site is already blocked by the error.</li>
<li>UBP must be installed first while the site is fully functional and then it’ll help you backing up your site if any newly Plugin produced an error.</li>
<li>It Won’t help you on all type of errors you’ve in your WordPress site however it can always give you the chance to get your site functional again after installing any Plugin that prevent you from accessing your backend.</li>
<li>It has no admin user interface and therefor not configurable, however next versions will do.</li>
<li>Send admin mail whatever ‘fatal errors’ is detected and it doesn’t matter if this error blocked your site or not. It’ll also report fatal errors that might happened in a secondary request that doesn’t block you from deacivating the Plugin yourself.</li>
</ul>
<h4>Proof Of Concept</h4>
<p>I still have many useful ideas and feature to add to the Plugin however the Plugin need users reviews to proof that its really helping and its really need to be improved.</p>


Uninterrupted Backup

Detect fatal errors that might be produced by the installed active Plugins, provide secure backdoor for deactivating the target Plugin.

Hagakure – Yet Another Error Reporter vs Uninterrupted Backup