The cache grows too large

POM Cache keeps generated files until invalidation or manual clearing removes them. It does not have an age-based garbage collector, so storage growth must be understood in terms of public URL and JSON variants.

Determine which store is growing

Open Settings → POM Cache → General and compare:

• Cache Contents for static HTML;
• Progressive JSON Cache Contents for JSON.

Record count and size at two or more times under representative traffic. On multisite, repeat for each site because the counters are current-site values.

Also monitor filesystem free space and inodes through the hosting platform. POM Cache's panels are content inventories, not capacity alerts.

Common HTML causes

HTML can grow because of:

• more public paths being visited;
• old slugs or permalink structures;
• multiple host aliases reaching WordPress without canonical redirects;
• language prefixes;
• inconsistent trailing slash or scheme handling;
• a storage-location migration that left the old tree;
• invalidation disabled for changes that retire URLs.

Meaningful query strings are normally not cached as static HTML. Do not mark them as tracking parameters to reduce storage unless they are guaranteed to produce the same representation.

Common JSON causes

Progressive JSON may have independent files for:

• locale;
• archive post type;
• pagination or progressive batch;
• public faceted filters;
• context hashes or key versions.

A deployment that changes the JSON key scheme does not automatically remove the preceding layout. Clear the current-site JSON store after confirming that the new scheme works.

Reset and measure the steady state

1. Record the current counts and deployed cache location.
2. Confirm that WordPress, Apache, and CDN use that same location.
3. Clear only the growing current-site store through POM Cache.
4. Exercise a representative route set.
5. Let normal traffic repopulate the cache.
6. compare the new growth curve with the expected URL and variant inventory.

If growth resumes without matching public variants, inspect canonical redirects and application-generated progressive paths.

Capacity planning

Allow space for:

• the steady-state artifacts;
• temporary files used for safe writes;
• short-term regrowth during deployments or traffic peaks;
• filesystem metadata and inode consumption.

Alert on both free bytes and inodes. Many small JSON files can exhaust inodes before they consume the expected byte capacity.

Remove obsolete storage safely

The POM Cache actions remove the configured current site's active store. If an old cache root remains outside it:

1. prove that current PHP and Apache configuration no longer references it;
2. identify its exact site and product scope;
3. back it up if rollback is required;
4. remove it through a reviewed hosting operation.

Never run a broad recursive deletion against wp-content, a shared cache root, or an unresolved variable. Do not remove another multisite site's tree.

If the active store grows correctly but the filesystem is too small, increase capacity or reduce valid public variants at the application-design level. Repeated cron deletion would turn normal visitors into perpetual cold misses without fixing the cause.