Limit cache key length #35
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This appears to have been fixed by Automattic for WordPress.com VIP customers in the copy of this plugin at https://github.com/Automattic/vip-go-mu-plugins/tree/develop/drop-ins/wp-memcached as part of Automattic/vip-go-mu-plugins@da8a798. The @WPprodigy Is there a timeline for when these are folded back in? The patches there don't look like breaking, large, or high-frequency changes so I wonder what led to the copy being preferred, or what risk there would be with committing them here instead (and updating the submodule). In any event, in the interim, merging these two fixes and a release for these and previously merged fixes, would be great! |
Follows-up 875339c, which explored apcu. Note that php-apcu in puppet was only ever installed. The WordPress apcu object-cache.php plugin was only tested locally on staging servers and has long since been removed. The problem with apcu in WordPress is that it isn't supported by WP-CLI currently (it is unable to purge the same logical keys, it would probably require the apcu WordPress plugin to implement some kind of WP-CLI endpoint over HTTP to relay purges). This could be worked around by having Puppet restart php-fpm after any WP-CLI command(s), but there is a simpler and arguably better solution which is to use the official memcached plugin. The state of memcached plugins is a bit of a mess at the moment: * https://wordpress.org/plugins/memcached/ https://github.com/Automattic/wp-memcached/ This is the oldest and most mature plugin, and has the benefit of being maintained by a first-party WordPress contributor (Automattic). Downsides: - Uses the older php-memcache client, instead of php-memcached. The latter is based on the seemingly more complete, widely used, and more actively maintained libmemcache (including support for igbinary). - Last release was 2 years ago. Improvements for recent WordPress versions (implement get_multiple) and recent PHP versions (fix PHP 8.2 deprecation warnings) are waiting to be released. - The GitHub repo has diverged from the WordPress.org SVN repo. The last change in the WordPress.org repo is https://plugins.trac.wordpress.org/changeset/2820882/memcached/trunk which is in fact missing from https://github.com/Automattic/wp-memcached/ The dozens of other changes in the GitHub repo are likewise missing from the SVN repo. - The maintainers have seemingly stopped using it themselves in favour of two internal forks, one at https://github.com/Automattic/wp-cache-memcached and another at https://github.com/Automattic/vip-go-mu-plugins/tree/develop/drop-ins/wp-memcached Neither seems committed to unforking and folding work back into the wordpress.org plugin. - Ref Automattic/wp-memcached#35 - Various forks and PRs exist to add php-memcached support, but nothing has made it into the repo to date. * https://wordpress.org/plugins/memcached-redux/ Forked from wp-memcached in 2012 to switch from php-memcache to php-memcached. Downsides: - Last release was even longer ago, 4 years ago. - Missing recent improvements and fixes, e.g. missing get_multple, and missing fixes for PHP 8.2 warnings about "Creation of dynamic property $cache_misses", etc. * Neither supports automatic installation, which is probably why their wordpress.org stats are so unbelievably low ("300+" and "30+" respectively), because people just copy the file by hand rather than installing via wp-admin or WP-CLI. Ref jquery/jquery-wp-content@fff52b7
Follows-up 875339c, which explored apcu. Note that php-apcu in puppet was only ever installed. The WordPress apcu object-cache.php plugin was only tested locally on staging servers and has long since been removed. The problem with apcu in WordPress is that it isn't supported by WP-CLI currently (it is unable to purge the same logical keys, it would probably require the apcu WordPress plugin to implement some kind of WP-CLI endpoint over HTTP to relay purges). This could be worked around by having Puppet restart php-fpm after any WP-CLI command(s), but there is a simpler and arguably better solution which is to use the official memcached plugin. The state of memcached plugins is a bit of a mess at the moment: * https://wordpress.org/plugins/memcached/ https://github.com/Automattic/wp-memcached/ This is the oldest and most mature plugin, and has the benefit of being maintained by a first-party WordPress contributor (Automattic). Downsides: - Uses the older php-memcache client, instead of php-memcached. The latter is based on the seemingly more complete, widely used, and more actively maintained libmemcache (including support for igbinary). - Last release was 2 years ago. Improvements for recent WordPress versions (implement get_multiple) and recent PHP versions (fix PHP 8.2 deprecation warnings) are waiting to be released. - The GitHub repo has diverged from the WordPress.org SVN repo. The last change in the WordPress.org repo is https://plugins.trac.wordpress.org/changeset/2820882/memcached/trunk which is in fact missing from https://github.com/Automattic/wp-memcached/ The dozens of other changes in the GitHub repo are likewise missing from the SVN repo. - The maintainers have seemingly stopped using it themselves in favour of two internal forks, one at https://github.com/Automattic/wp-cache-memcached and another at https://github.com/Automattic/vip-go-mu-plugins/tree/develop/drop-ins/wp-memcached Neither seems committed to unforking and folding work back into the wordpress.org plugin. - Ref Automattic/wp-memcached#35 - Various forks and PRs exist to add php-memcached support, but nothing has made it into the repo to date. * https://wordpress.org/plugins/memcached-redux/ Forked from wp-memcached in 2012 to switch from php-memcache to php-memcached. Downsides: - Last release was even longer ago, 4 years ago. - Missing recent improvements and fixes, e.g. missing get_multple, and missing fixes for PHP 8.2 warnings about "Creation of dynamic property $cache_misses", etc. * Neither supports automatic installation, which is probably why their wordpress.org stats are so unbelievably low ("300+" and "30+" respectively), because people just copy the file by hand rather than installing via wp-admin or WP-CLI. Ref jquery/jquery-wp-content@fff52b7
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Hi! So the newer plugin is mainly built for the I do agree though, it would be good to port over the |
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@WPprodigy Yeah, I'm aware of the difference in PECL extensions used. I believe numerous forks and PRs exist that add support for that. Are you open to that direction still, where both are supported and auto-detected together, keeping this plugin as the main plugin? (I'd favour, like you probably, to check the libmemcached-based php-memcached, first, in case both are installed for some reason.). It seems like that would be doable without a compat break, and fairly minimal code complexity increase. Basically a handful of "if" statements (or, if we prefer composition, by invoking one of two compatible sub classes in |
Memcache has a key length limit of 250 characters. Problems can arise if a cache key greater than this is used. It seems memcache truncates the key so it is very possible to have collisions and unexpected behavior. Other object caches can handle very large keys so this object cache should check if a key is too long and hash it with md5 or similar to prevent problems.
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