The do_send_messages() populates the user_presences data structure
for process_new_message(), so that Tornado code never needs to hit
the database or memcached to get the user presence info.
(imported from commit 194aeaead8fa712297a2ee8aff5aa773b92f1207)
This reduces the number of memcached calls we make in our time-
slice-limited tornado event handler.
(imported from commit 8903ce4ac754ba82d57e04d1b0356be7533edee2)
We found that since bugdown processes are threaded, the cost of
doing a db query in a markdown processor is quite high---each
thread must start up a new db connection including a SSL handshake
etc. We should strive to keep our rendering pipeline free of mandatory
DB queries.
(imported from commit 555066bd03da6c681b74ce6137acc264eb41c55d)
This needs to be deployed to both staging and prod at the same
off-peak time (and the schema migration run).
At the time it is deployed, we need to make a few changes directly in
the database:
(1) UPDATE django_content_type set app_label='zerver' where app_label='zephyr';
(2) UPDATE south_migrationhistory set app_name='zerver' where app_name='zephyr';
(imported from commit eb3fd719571740189514ef0b884738cb30df1320)
Steve Howell
Leo Franchi
Jessica McKellar
Tim Abbott