Support » Plugin: WP Super Cache » [Plugin: WP Super Cache] option descriptions are incomprehensible

  • option descriptions are incomprehensible.

    Don’t cache pages for known users. (Logged in users and those that comment)

    i can understand this this way: it mean don’t cache at all i.e. even do not use wp-cache for them. i think it can be needed to always show most correct content to them.

    Cache rebuild. Serve a supercache file to anonymous users while a new file is being generated. Recommended for very busy websites with lots of comments. Makes “directly cached pages” and “Lockdown mode” obsolete.

    this is checked by default.
    and i do not understand this.
    why it is called “Cache rebuild”?
    “Serve a supercache file to anonymous users while a new file is being generated.” hm. what is “a supercache file” that exists while “a new file is being generated” -> it is old version of file that is being generated -> the corresponding page content is just updated and for that the cache files (gz and html) are being updated, before they are ready, old versions are served to “guests”(“anonymous”). what happen if this is unchecked -> the files are somehow checked ie locked when content is updated and when they are requested by anonymous, they are not served, but page is generated with php. this is as i [can] understand it.
    <q>Makes “directly cached pages” and “Lockdown mode” obsolete.</q> – why? and what does this mean? this like turns off “directly cached pages” and “Lockdown mode”? why? why directly cached pages cannot work with this option? i think they can (, as understand this option). why “Lockdown mode” cannot work? i think it can, and even this option itself can become then like not correct, so obsolte.
    so maybe i understand this option not correctly.

    Coarse file locking. You probably don’t need this but it may help if your server is underpowered. Warning! May cause your server to lock up in very rare cases!

    hm. what is “Coarse file locking” and “usual” wp-super-cache locking? and when locking is used? when that file is updated?

    List the newest cached pages (may be expensive to run on busy sites, use with caution.)

    where to list? in dashboard?

    Mobile device support.

    it is unchecked. but i see “Mobile rewrite rules detected”. so, if rules are detected, why it ie support is unchecked? ahh.. rewrite rules are turning off cache for mobile devices. i understand this, but do not delete this paragraph, for some readers of this post.
    6. “Garbage Collection” – what is this? i do not understand. why it is needed, what it does? is there garbage? how? i think there cannot be garbage ie incorrect, obsolete files because files are immediately updated (with usual and default configuration) when corresponding content is changed – new comment is made or post edited. also when post is deleted or made private, probably cache file is immediately deleted.

Viewing 10 replies - 1 through 10 (of 10 total)
  • Plugin Author Donncha O Caoimh


    1. Yes, you understand it correctly.
    2. It serves a slightly out of date supercache file while a new supercache file is being generated for a given page. If 10 people hit a page at the same time, the first request handled will start generating a new cache page. Meanwhile the other 9 people get the slightly out of date file that already exists for that page. Only if the file is less than 30 seconds old however. Otherwise your server will try to create 10 new cache files for the same page. That’s why it makes the other caching options obsolete. It boosts performance by a huge amount!
    3. It’s a lock put around the whole cache file creation process and a legacy of wp-cache. The plugin now creates cache files with temporary filenames so there’s very little chance of collision during cache creation. This option will likely disappear before 1.0 is released.
    4. On the supercache admin page.
    5. Needs to be improved.
    6. GC removes old cache files. Files aren’t immediately updated unless an external action (like a comment being made) is taken. The GC cleans out those files older than a configurable age.

    directly cached pages saves cache files in root directory, how does it increase performance? maybe rewrite rules are not used? btw directly cached pages option has disappeared in my wp super cache admin page, maybe because i clicked “restore default config”.
    lockdown mode can still (while “Cache rebuild” is enabled) give additional performance, i think, because time of generating new cache files is saved.

    GC. i think, there can be content change in some pages, maybe for example if new category or tag added and added to some pages, so category menu should be updated on all pages. so if GC works it can check all files like by cron every 10 minutes or some period and delete all files that are written more than “expiry time” ago, regardless, whether they have unupdated content like new category in sidebar or not. (i assume here that wp super cache does not delete all cached pages immediately after new category addition and addition a post to it so it show up, i assume empty category is not visible in sidebar)
    “If … garbage collection will be done every 10 minutes” – there is said “every” and there – “otherwise it will happen 10 seconds after the expiry time above.” – is said “after” , why, in second case it happens only one time (once)? it sounds like that for me.
    “but it’s expensive leaving them there too” – why ? if expired files need not updating, leaving them will increase performance without any disadvantage, for example without need to work/rebuild something hardly/{more hard} later.
    “Aim to have less than 500 cached files if possible.” – why? more pages cached – more pages work fastly, is not it?
    i think you should list what editions update cache files and what not in readme, like that new comment or content edit immediately update it and index page, but addition or deleting categories or tags or changing tag size in tag cloud do not update all pages in which categories menu and tag cloud is visible in sidebar, it need to be updated with GC or deleting all cache.

    and what is expire time? it confuses, whether it is for http expire header or just for GC?

    expire time is not http expire time, http expire header is given/written in “.htaccess” file which is in folder of cache and it is “300” ie 5 minutes.

    “half on” ie “wp-cache” mode and “on” ie “super cache” mode work with different principle, also have different cache files, so, i think, they should be explained separately, and cache options should be separated in the plugin’s admin panel.

    btw seems donncha redesigns admin panel: .

    in i have written a comment, with link to this topic, that post has not appeared! why?

    Plugin Author Donncha O Caoimh


    I can’t see a comment from you, but there’s no need to post a link to this thread. I’m already well aware of it 🙂

    comment is not only for you, link is because other people has written to same topic there and i have already have written to that topic here, i should not copy what i said from here to there, instead i just post link. And there was cite of my last suggestion/critic. I have saved my comment, I can repost. But maybe it’s in some spam trap’s basket?

    Plugin Author Donncha O Caoimh


    I can’t find your comment anywhere, in pending or spam. If you like, please post it again and I’ll certainly let it through to the post.

    i have just now posted it, it again have not appeared immediately.
    i have modified it, not exact copy of what i posted day before yesterday.

Viewing 10 replies - 1 through 10 (of 10 total)
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