README

After a deploy or a cache flush the full page cache is empty, and the first visitor of every page waits while Magento builds it (half a second to several seconds; a cached page answers in tens of milliseconds). This module requests the pages visitors open most, once, before they do.

Install

Requires Magento Open Source 2.4.7–2.4.9 and PHP 8.2–8.4 with the GD extension built with WebP (php -r 'var_dump(function_exists("imagewebp"));' says true; Magento's own PHP requirements cover the rest). Without WebP in GD, Zero skips its WebP image copies and serves the originals.

composer require zerofront/module-zero-cache-warmer
bin/magento setup:upgrade
bin/magento setup:di:compile           # production mode
bin/magento setup:static-content:deploy # production mode
bin/magento cache:flush

Composer installs zerofront/module-zero-core with it.

Part of zerofront/zero, which installs the Zero theme and every Zero module at once.

What it warms

For each active store view, by priority:

the home page;
the top-level categories;
the deeper categories, top levels first; with 2. up to Categories per Store View (default 500: 2 000 categories took an hour to warm, one at a time);
the CMS pages (not the home page's own URL, not no-route);
the paths in Also Warm (default brands, blog);
the products: the best sellers of the last 90 days, then the newest, up to Products per Store View (default 30).

The order goes by priority across the store views, not store view by store view: every storefront's home page first, then every top-level category, and so on, one page of each storefront in turn within a level. So the last store views no longer wait minutes for the first ones' products. A URL is asked once per run: store views that share an address (default, europe_eur, arabic_rtl and luma_compare on one domain) share its cache entries.

URLs come from url_rewrite, so stores served under a path (/shop/) and their own domains are covered. Rewrites that can only answer 404 are left out at the query: categories outside the store view's root category, and URLs with an empty URL key (/.html). Pages are warmed as a guest sees them; a signed-in customer group or another currency has its own cache entry and is not warmed.

When

After a deploy: scripts/after_install.sh runs bin/magento zero:cache:warm --later (queues a full warm and returns); a deploy that changes only some store views can queue just those (--later --store=…).
After Flush Magento Cache / Flush Cache Storage in the admin.
After a save: a product (with its categories), a category or a CMS page is warmed again (setting Warm a Page After It Is Saved). Up to 500 pages per type are queued, so an import doesn't queue thousands.

The queue lives in the flag table (zero_cache_warmer_queue); the cron job zero_cache_warmer_run (every minute) does what it holds. One run at a time: the cron and the command share a lock.

How

With Varnish (Stores > Configuration > Advanced > System > Full Page Cache = Varnish and http_cache_hosts in env.php), requests go to Varnish itself with the page's Host and X-Forwarded-Proto — the same cache entry the public HTTPS server would make, without CloudFront, TLS or the crawlers' speed limit in between. With Magento's own cache, the store's URL is requested directly.
One request at a time, Pause Between Requests (default 100 ms) between them; while the 1-minute load average is above Wait While the Load Is Above (0: the number of CPU cores, read from /proc/cpuinfo) it waits, 5 s at a time, up to 5 minutes. Visitors come first.
User agent ZeroCacheWarmer/1.0. A run ends with one line in var/log/system.log: pages, seconds, cached, not found, failed.

Command

bin/magento zero:cache:warm                 # every store view, now
bin/magento zero:cache:warm --store=default,german --products=100 -v
bin/magento zero:cache:warm --dry-run       # only list the URLs
bin/magento zero:cache:warm --later         # leave it to the next cron run
bin/magento zero:cache:warm --later --store=german # only those store views, next cron run

A queued warm of some store views and a queued one of every store view together warm every store view; two of some store views warm both lists.

Settings

Stores > Configuration > Zero > Cache Warmer (default scope): Enabled, Categories per Store View, Products per Store View, Also Warm, Warm a Page After It Is Saved, Pause Between Requests, Wait While the Load Is Above.

Tests

Test/Unit: the Varnish request (Host, scheme, ports), the queue (once per page, the cap, full, full of some store views), outcomes, paths kept once in order, the tiers and the 404 filters of the queries (UrlsTest), the order across store views and a URL once (WarmerTest), --later --store (WarmCommandTest), the Also Warm setting cleaned. Measured on a demo store, time to first byte: locally (built-in cache) cold 0.1–1.0 s (home 0.38 s), warm 37–88 ms, 73 pages warmed in 30 s; on production (Varnish, m7i.large) a page Magento builds takes 0.5–0.7 s the first time, 0.2 s with its block caches warm, 0.09–0.11 s from Varnish (most of it the network from Europe to us-east-1).

What changed in each release: CHANGELOG.md.

License

OSL-3.0 or AFL-3.0, your choice: see NOTICE.md.

Zero is made by Fixstacks in partnership with Vilmate, a software development company. Documentation: https://zerofront.dev/docs. Demo store: https://demo.zerofront.dev.

zerofront / module-zero-cache-warmer

Package info

Security

Statistics