Super Cache hanging until max execution time during garbage collection

[dominic-p]

Impacted plugin

Super Cache

Quick summary

I have noticed some critical errors in my PHP logs that seem to be related to WP Super Cache. The log entries look like this:

Maximum execution time of 30 seconds exceeded
{
    "error": {
        "type": 1,
        "file": "/srv/public_html/wp-content/plugins/wp-super-cache/wp-cache-phase2.php",
        "line": 2673
    },
    "remote-logging": true,
    "backtrace": [
        {
            "file": "/srv/public_html/wp-content/plugins/woocommerce/includes/class-woocommerce.php",
            "line": 413,
            "function": "critical",
            "class": "WC_Logger",
            "type": "->"
        },
        {
            "function": "log_errors",
            "class": "WooCommerce",
            "type": "->"
        }
    ]
}

The woocommerce file is just the one that is capturing the log message. I looked at line 2673 and that appears to be calling is_dir(). I'm not sure how that could be hanging for 30 seconds, but that appears to be what's going on.

This error is happening intermittently, but regularly according to the logs. It looks like it happened once every 4 hours yesterday. Interestingly, I have the Garbage Collection set to run on a schedule every 14400 seconds (4 hours).

Possibly relevant environment info:
WP Super Cache version: 2.0.0
PHP version: 8.1.31
Server: Apache

Steps to reproduce

I'm not sure.

Site owner impact

Fewer than 20% of the total website/platform users

Severity

Minor

What other impact(s) does this issue have?

No revenue impact

If a workaround is available, please outline it here.

No response

Platform (Simple and/or Atomic)

Self-hosted

[github-actions]

OpenAI suggested the following labels for this issue:

• [Feature Group] Support: The issue relates to a functionality problem in a plugin that users may need support for.
• [Feature] Error Reporting: The issue involves critical errors being logged, which is directly related to error reporting functionality.
• [Feature] WP Super Cache: The issue specifically mentions the WP Super Cache plugin, which is experiencing hanging and execution time errors.