WebCache

Web page caching

Some pages on your project's web site are accessed often and require lots of database access to generate. To keep this from bogging down your server, BOINC caches these pages. This cache is in PROJECT/html/cache/*; a one-level hashed directory hierarchy is used to deal with large-directory performance problems.

Caching configuration

The file html/project/cache_parameters.inc contains a number of parameters related to caching:

TEAM_PAGE_TTL

Cache life of team pages; default 1 hour

USER_PAGE_TTL

Cache life of user pages; default 1 hour

USER_HOST_TTL

Cache life of user host list; default 1 hour

USER_PROFILE_TTL

Cache life of profiles; default 1 hour

TOP_PAGES_TTL

Cache life of user/team/host lists; default 12 hours

INDEX_PAGE_TTL

Cache life of main page; default 1 hour

MAX_CACHE_USAGE

Max cache size; default 100 MB

MIN_FREE_SPACE

Min free space on device; default 100 MB

CACHE_SIZE_CHECK_FREQ

Check cache size on every N user accesses to cached pages; default 1000

Caching and translation

BOINC uses several web-page caching systems, which support language translation in different ways.

• Pre-generated: Pages are updated from time to time, and do not support translation. The system used for building profiles is a pre-generated cache.
• Fullpage cache: This cache system simply takes the output of a page and saves it for the future. It uses the start_cache() and end_cache() functions in cache.inc. The pages may not be translation-aware (otherwise some users will see the wrong language).
• Fullpage cache with translation: You can make the language part of the cache filename. (To do this, you need to adapt the code in cache.inc). This can be inefficient because it stores a separate copy of the page for each language.
• Object cache: This stores the data used to create the page and recreates the page every time (using any language you'd like). Use get_cached_data() in cache.inc. This is perfect for pages that are accessed commonly and by people from many nationalities (currently the top-X pages support it).

If something shows up in the wrong language it's probably because a page that was previously not being translated got translation abilities but wasn't moved to the proper cache type. Also if a page-piece that is included is now translatable, all pages that make use of this piece should now either use fullpage caching with translation, or use an object cache (nicer but takes a few more lines of coding).