David

Hi @lovingbro ,

Thanks for the clarification and for pointing out that the fix is included in WooCommerce 10.3.2. I really appreciate the quick follow-up.

Since this is a production site, I’ll hold off on testing beta builds, but it’s good to know that the issue has already been addressed.

Thanks again for the update!

Best,
David

Hi @inpsydekrystian ,

Thank you for providing the download link to a version with the fix. I’ve been using it for a few days now and haven’t noticed a problem. And the warnings have disappeared. Thanks again!

Hi @qtwrk ,

I checked it with the server support, redis mem limit is set to 16GB on our server, so 4.4 GB should still be ok. I also tried your proposal and disabled Redis in LiteSpeed temorarily but the issue still occured. Just with a new error message:

PHP Fatal error:  Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class "LiteSpeed\Thirdparty\Aelia_CurrencySwitcher" not found in /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php:324

Stack trace:
#0 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#1 /var/www/vhosts/example.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#2 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php(379): do_action()
#3 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(324): LiteSpeed\Core->load_thirdparty()
#4 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#5 /var/www/vhosts/example.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#6 /var/www/vhosts/example.com/httpdocs/wp-settings.php(665): do_action()
#7 /var/www/vhosts/example.com/httpdocs/wp-config.php(96): require_once('...')
#8 /var/www/vhosts/example.com/httpdocs/wp-load.php(50): require_once('...')
#9 /var/www/vhosts/example.com/httpdocs/wp-blog-header.php(13): require_once('...')
#10 /var/www/vhosts/example.com/httpdocs/index.php(17): require('...')
#11 {main}
  thrown in /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php on line 324

PHP Fatal error:  Uncaught Error: Class "LiteSpeed\Utility" not found in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/control.cls.php:637

Stack trace:
#0 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php(572): LiteSpeed\Control->finalize()
#1 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php(487): LiteSpeed\Core->send_headers()
#2 [internal function]: LiteSpeed\Core->send_headers_force()
#3 {main}
  thrown in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/control.cls.php on line 637

PHP Fatal error:  Uncaught Error: Class "LiteSpeed\File" not found in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php:437

Stack trace:
#0 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php(569): LiteSpeed\Core->_check_is_html()
#1 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(324): LiteSpeed\Core->send_headers()
#2 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#3 /var/www/vhosts/example.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#4 /var/www/vhosts/example.com/httpdocs/wp-includes/load.php(1260): do_action()
#5 [internal function]: shutdown_action_hook()
#6 {main}
  thrown in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/core.cls.php on line 437

Any other idea what could cause this?
Thank you.

Hi @bisratlearn

Please pass this topic on to the developers and please don’t just paste this standard ChatGPT answer everywhere, thanks

Hi @qtwrk,

Thank you for your response. I added the logging as you mentioned and received the following during today’s incident:

LiteSpeed Cache Warning: Undefined $res. Key – 24ac5options.alloptions, Data – a:1:{s:4:”data”;a:1167:{s:20:” … Here a huge block of data continues, followed by about 1500 lines of website html. Unfortunately it did not track any Expire.

Apart from that, it was recorded much better today how the error builds up from the warning message to a critical error. This is the sequence of events from the log. If you could provide me with further assistance based on this, I would be very grateful.

LiteSpeed Cache Warning: Undefined $res. Key - 24ac5options.alloptions, Data ...

PHP Warning: Undefined variable $res in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php on line 490

PHP Notice: Redis::setex(): send of 8192 bytes failed with errno=11 Resource temporarily unavailable in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php

PHP Notice: Redis::setex(): Send of 4410762 bytes failed with errno=11 Resource temporarily unavailable in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php on line 470
...

Undefined variable $res in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php on line 490

PHP Fatal error: Uncaught RedisException: read error on connection to localhost:6379 in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php:434 Stack trace: #0 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php(434): Redis->get() #1 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object.lib.php(777): LiteSpeed\Object_Cache->get() #2 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object.lib.php(160): WP_Object_Cache->get() #3 /var/www/vhosts/example.com/httpdocs/wp-includes/option.php(599): wp_cache_get() #4 /var/www/vhosts/example.com/httpdocs/wp-includes/option.php(845): wp_load_alloptions() #5 /var/www/vhosts/example.com/httpdocs/wp-includes/cron.php(1242): update_option() #6 /var/www/vhosts/example.com/httpdocs/wp-includes/cron.php(523): _set_cron_array() #7 /var/www/vhosts/example.com/httpdocs/wp-cron.php(156): wp_ in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/litespeed-cache/src/object-cache.cls.php on line 434

Hi @qtwrk

Thank you for your response.

I further analysed this issue. While the warning about the undefined $res variable is consistent, I’ve observed a couple of other errors occurring around the time of the memory spikes:

The first is related to Wordfence:

PHP Fatal error: Uncaught Error: Class "WordfenceLS\Controller_DB" not found in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/wordfence/modules/login-security/classes/model/settings/db.php:73

This error suggests there might be a compatibility issue with Wordfence, specifically with the login security module.

Another error I encountered is related to a third-party integration with LiteSpeed:

PHP Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class "LiteSpeed\Thirdparty\Aelia_CurrencySwitcher" not found in /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php:310

To answer your questions:

• The issue has occurred several times, and I have not tried disabling the object cache due to its importance for my site’s performance.
• Regarding the debug log code before the undefined $res warning, I have not noticed any logs indicating the value it tries to set. If there’s a specific logging method or level you recommend, I can certainly implement it to gather more detailed information during these events.

Based on these additional errors, it does seem like there could be a compatibility issue at play. Any further insights or assistance you can provide would be greatly appreciated.

Additionally, I have two follow-up questions that could help me

1. Is there a way to limit the memory consumption of the LiteSpeed Cache plugin directly? If a setting or a tweak could prevent the plugin from using a certain amount of memory, it would be a great interim solution.
2. Does LiteSpeed Cache have a feature to automatically flush all caches if a certain memory usage threshold is hit? An automatic cache purging mechanism under specific conditions might prevent the server from reaching a critical state

Thank you for your help.

Hi @stevejburge

Thanks for getting back to me so quickly. I just actiated the previous version in order to see whats missing and it looks like the complete left section is missing now. I will attach you before and after screenshots.
Before: https://imgur.com/a/0LXrkDV
Now: https://imgur.com/a/gpV4w2S

Thanks for checking this!

Hi @qtwrk

report number is FZATUYBA. Its a single site. Thanks for looking into this.