Is there any documentation about what should happens exactly with the followings bolded, how they exactly interact each-other:
in /admin/config/system/boost
Cache HTML output, usually a webpage of type text/html
Cache Enabled
Filename Extension
text/html - Maximum Cache Lifetime
text/html - Minimum Cache Lifetime
in /admin/config/system/boost/expiration
Ignore a cache flush command if cron issued the request.
Remove old cache files on cron.
in /admin/config/development/performance
Minimum cache lifetime
Cached pages will not be re-created until at least this much time has elapsed.
Expiration of cached pages
The maximum time an external cache can use an old version of a page.
I'm not sure that #1430942: All caches are flushed on every cron is solved for me.
It seems I've got cache flushed before expiration date.
Per exemple, is the file expiration calculated when created or when compared to parameters in the settings? In first case, changing the setting after the file creation don't affect its expiration date.
| Comment | File | Size | Author |
|---|---|---|---|
| #3 | boost-1450516-ui-doc.patch | 1.51 KB | bgm |
Comments
Comment #1
gnal commentedAfter having a look at the code, this is what I understand:
Boost cache:
"Ignore a cache flush command if cron issued the request": drupal_flush_all_caches() is drupal's function that clears all caches (Clear button on the Performance page or whenever it is invoked). Boost will clear its cache whenever this function is called, except if cron has made the call and this option is enabled. Cron calls the function at "Minimum cache lifetime" intervals.
"Remove old cache files on cron": if enabled, each time cron runs boost will check each cached page and will delete those that have expired. To see when a page expires see the comment that boost adds to the bottom of the html pages it creates.
"Maximum Cache Lifetime": used by cron to calculate the expiration date/time of each page.
"Minimum Cache Lifetime": I don't know about this one, it does not seem to be implemented.
Drupal's core cache:
"Minimum cache lifetime": drupal's core cache lifetime. Cron checks if this much time has passed since the last time the cache was cleared and accordingly issues a drupal_flush_all_caches().
"Expiration of cached pages": This only applies for external caching mechanisms, for example your browser cache or Varnish (see http://blog.merge.nl/20120118/how-does-caching-work-drupal)
Can someone confirm that the above are correct?
Also, in drupal 6 the boost module automatically disables core drupal caching when it is enabled. Is it best to have the core cache disabled in d7 also?
Comment #2
rondev commentedThank you that helps a lot.
"To see when a page expires see the comment that boost adds to the bottom of the html pages it creates."
Then the expiration date is defined when the page is created. That is what I supposed.
Correction:
No a date is written in the cached page as a comment. But the expiration date may change if you change the expiration time in the parameters as boos calculate the ellapsed time
and then compare it to the lifetime given
"Remove old cache files on cron": it seems I had a cache pages deleted even if this one was unchecked. I have to control again.
Comment #3
bgm commentedYes, otherwise your boost cache may never be generated if Drupal manages to cache the page before boost.
Minimum cache lifetime: right, it's not really used by Boost. Seems to be there as an option in case other modules want to implement hook_boost_storage_types().
Based on the descriptions in #1, here is a patch to improve the admin interface. What do you think?
* Ignore a cache flush command if cron issued the request.: 'Drupal will flush all caches when cron is executed, depending on the core minimum cache lifetime setting. To ignore the request to flush the cache on cron runs, enable this option. If enabled, pages in the Boost cache will be flushed only when their Boost maximum cache lifetime expires.'
* Remove old cache files on cron.: 'If enabled, each time cron runs Boost will check each cached page and delete those that have expired (maximum cache lifetime). The expiration time is displayed in the comment that Boost adds to the bottom of the html pages it creates. This setting is recommended for most sites.'
Comment #4
rondev commentedIt is right for me.
Comment #5
bgm commentedCommitted to 7.x-1.x.