Deployment instructions: I think all the queue workers get
restarted automatically, so there is probably nothing special
to do here in the deploy itself, but we will want to monitor
it closely, and the change should make our number of locks go
down.
QueueProcessingWorker.start() now calls consume_and_commit(),
which ensures that we don't hold locks after work actions
by using Django's commit_on_success() decorator.
Obviously, workers that override start() will not call consume_and_commit()
through this code path. SlowQueryWorker calls commit_on_success()
in its start() method now, and I hope to address MissedMessageWorker soon.
(imported from commit f3f38a7f45730eee8f3b5794371ba5b994017676)
These are some queries on API usage, desktop usage, and
Android usage that would be of interest to Waseem. These
will eventually be subsumed into /activity, but some interim
data issues may make them easier to keep separate for now.
(imported from commit 697a8496cbf4447d557a3fc89f64c1c4d3e67e70)
In order to support iOS Push Notifications, we need to keep track
of a device's unique APNS Token. These are delivered to our iOS
code after registering for remote notifications
(imported from commit bbe34483e1380dc20a1c93e3ffa1fcfdb9087e67)
Use the commit_on_success() context manager around the call
to internal_send_message() inside of SlowQueryWorker's polling
loop, so that the pending SELECT statement from
get_status_dict_by_realm() gets committed. If we don't do
this, postgres will hold locks on zerver_userprofile, and other
tables, for a long time, which can interfere with migrations.
This is an interim solution until we switch postgres's default
commit behavior. Right now the default transaction isolation
is "read committed," so SELECT statements lead to AccessShareLocks
that do no get closed until the transaction finishes.
(imported from commit f72aeffbbe71a731e327459f15bd7dbebaf9e0b8)
Trac #1162
The process_fence method replaces code blocks with placeholders, so
indexes stored before the replacement are incorrect. However, because
the closed code blocks have been replaced, we can simply search the
whole string for any remaining opening code block markers.
(imported from commit 6a9e6924840f8f3ca5175da7c52a905e27c1fabd)
I added filter() statements to do_update_message_flags().
Here is some context:
Steve Howell: Case 1, have AND clause to reduce work for DB.
humbug=> update zerver_usermessage set flags = (flags & ~1) where id > 9000;
UPDATE 382
humbug=> select count(*) from zerver_usermessage where (flags & 1) = 0;
count
-------
382
(1 row)
humbug=> explain analyze update zerver_usermessage set flags = (flags | 1) where (flags & 1) = 0;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
Update on zerver_usermessage (cost=0.00..266.85 rows=47 width=27) (actual time=5.727..5.727 rows=0 loops=1)
-> Seq Scan on zerver_usermessage (cost=0.00..266.85 rows=47 width=27) (actual time=0.045..2.751 rows=382 loops=1)
Filter: ((flags & 1::bigint) = 0)
Rows Removed by Filter: 9000
Total runtime: 5.759 ms
(5 rows)
humbug=> select count(*) from zerver_usermessage where (flags & 1) = 0;
count
-------
0
(1 row)
Leo Franchi: Sounds reasonable, but I know way less than zev about DBs so I'll defer to his judgement :)
Steve Howell: Case 2, how the code works now:
humbug=> update zerver_usermessage set flags = (flags & ~1) where id > 9000;
UPDATE 382
humbug=> select count(*) from zerver_usermessage where (flags & 1) = 0;
count
-------
382
(1 row)
humbug=> explain analyze update zerver_usermessage set flags = (flags | 1);
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------
Update on zerver_usermessage (cost=0.00..243.28 rows=9382 width=27) (actual time=362.075..362.075 rows=0 loops=1)
-> Seq Scan on zerver_usermessage (cost=0.00..243.28 rows=9382 width=27) (actual time=0.008..6.138 rows=9382 loops=1)
Total runtime: 362.105 ms
(3 rows)
humbug=> select count(*) from zerver_usermessage where (flags & 1) = 0;
count
-------
0
(1 row)
Steve Howell: In both trials, we set it up so that only 382 of 9382 rows need to be updated. The first trial runs about 63x as fast. The second trial, if my theory is correct, is doing 24x as many writes as it needs. Both trials are reading all 9382 rows.
Steve Howell: The expense of the update statement seems to be proportional to the number of rows you "update", not the number of rows that you actually change.
Steve Howell: For now I created #1869.
Zev Benjamin: That sounds like a reasonable explanation. The disk IO can be expensive
(imported from commit d9090daee1f81cad76c430de0956f9bd504da075)
Handled by the queue processor for signups. Added a management command
that accomplishes the same task, in case it's needed for manually added users,
or in case we goof and need to remove queued emails for a given user.
This addresses Trac #1807
(imported from commit 6727b82a07fa6a3ea3d827860c9e60fd0602297a)
We want to avoid opening a DB connection in the markdown thread
as its DB connection might live for a long time
(imported from commit 7700b2ca793ee5e9add7f071b92f22a4bf576b3d)
This will hopefully incentivize people to click one and get back into
the app.
We'll also need this for digest emails.
(imported from commit 57191c3fcca3b12df93a81e4692bb7eb8ccc83b2)
This requires renaming the account in Google Apps at the time we
deploy this; we'll probably want to do this during off hours to avoid
any user-visible downtime.
This also updates some related email addresses.
(imported from commit fce7629b359a4f278bbf7815c8d177a8fa0484fe)
This may require just doing an mv on the home directory, plus changing
the home directory in /etc/passwd. It should of course be done carefully.
(imported from commit 660997d897ee6d33563af74f0fc5d4267a911755)
A few "slow" tests aren't as slow any more, for whatever reason,
so we're setting a higher bar going forward.
(imported from commit 642137cebb7826f4512b5635da9d7b75bd5c35f4)
Steve Howell
Jessica McKellar
Leo Franchi
Kevin Mehall
Tim Abbott
Zev Benjamin
acrefoot
Luke Faraone