2020-02-07 22:40:11 +00:00
|
|
|
Notes for any sites which require extra performance
|
|
|
|
|
===================================================
|
|
|
|
|
|
|
|
|
|
Image Serving
|
|
|
|
|
-------------
|
|
|
|
|
Firstly, make sure your webserver is configured properly and nice URLs are
|
|
|
|
|
enabled, so that images will be served straight from disk by the webserver
|
|
|
|
|
instead of via PHP. If you're serving images via PHP, then your site might
|
|
|
|
|
melt under the load of 5 concurrent users...
|
|
|
|
|
|
2020-02-07 22:42:12 +00:00
|
|
|
Add a Cache
|
|
|
|
|
-----------
|
|
|
|
|
eg installing memcached, then setting
|
|
|
|
|
`define("CACHE_DSN", "memcache://127.0.0.1:11211")` - a bunch of stuff will
|
|
|
|
|
get served from the high-speed cache instead of the SQL database.
|
|
|
|
|
|
2020-02-07 22:40:11 +00:00
|
|
|
`SPEED_HAX`
|
|
|
|
|
-----------
|
|
|
|
|
Setting this to true will make a bunch of changes which reduce the correctness
|
|
|
|
|
of the software and increase admin workload for the sake of speed. You almost
|
|
|
|
|
certainly don't want to set this, but if you do (eg you're trying to run a
|
|
|
|
|
site with 10,000 concurrent users on a single server), it can be a huge help.
|
|
|
|
|
|
|
|
|
|
Notable behaviour changes:
|
|
|
|
|
|
|
|
|
|
- Database schema upgrades are no longer automatic; you'll need to run
|
|
|
|
|
`php index.php db-upgrade` from the CLI each time you update the code.
|
|
|
|
|
- Mapping from Events to Extensions is cached - you'll need to delete
|
|
|
|
|
`data/cache/shm_event_listeners.php` after each code change, and after
|
|
|
|
|
enabling or disabling any extensions.
|
|
|
|
|
- Tag lists (eg alphabetic, popularity, map) are cached and you'll need
|
|
|
|
|
to delete them manually when you feel like it
|
|
|
|
|
- Anonymous users can only search for 3 tags at once
|
|
|
|
|
- We only show the first 500 pages of results for any query, except for
|
|
|
|
|
the most simple (no tags, or one positive tag)
|
|
|
|
|
- We only ever show the first 5,000 results for complex queries
|
|
|
|
|
- `ParseLinkTemplateEvent` is disabled
|
|
|
|
|
- Only comments from the past 24 hours show up in /comment/list
|
|
|
|
|
- Web crawlers are blocked from creating too many nonsense searches
|
|
|
|
|
- The first 10 pages in the index get extra caching
|
|
|
|
|
- RSS is limited to 10 pages
|
|
|
|
|
- HTML for thumbnails is cached
|
|
|
|
|
|
|
|
|
|
`WH_SPLITS`
|
|
|
|
|
-----------
|
|
|
|
|
Store files as `images/ab/cd/...` instead of `images/ab/...`, which can
|
|
|
|
|
reduce filesystem load when you have millions of images.
|
|
|
|
|
|
|
|
|
|
Multiple Image Servers
|
|
|
|
|
----------------------
|
|
|
|
|
Image links don't have to be `/images/$hash.$ext` on the local server, they
|
|
|
|
|
can be full URLs, and include weighted random parts, eg:
|
|
|
|
|
|
|
|
|
|
`https://{fred=3,leo=1}.mysite.com/images/$hash.$ext` - the software will then
|
|
|
|
|
use consistent hashing to map 75% of the files to `fred.mysite.com` and 25% to
|
|
|
|
|
`leo.mysite.com` - then you can install Varnish or Squid or something as a
|
|
|
|
|
caching reverse-proxy.
|
|
|
|
|
|
|
|
|
|
Profiling
|
|
|
|
|
---------
|
|
|
|
|
`define()`'ing `TRACE_FILE` to a filename and `TRACE_THRESHOLD` to a number
|
|
|
|
|
of seconds will result in JSON event traces being dumped into that file
|
|
|
|
|
whenever a page takes longer than the threshold to load. These traces can
|
|
|
|
|
then be loaded into the chrome trace viewer (chrome://tracing/) and you'll
|
|
|
|
|
get a breakdown of page performance by extension, event, database, and cache
|
|
|
|
|
queries.
|
