Commit Graph

11 Commits

Author SHA1 Message Date
Erik Johnston 19b15d63e8
Use autocommit mode for single statement DB functions. (#8542)
Autocommit means that we don't wrap the functions in transactions, and instead get executed directly. Introduced in #8456. This will help:

1. reduce the number of `could not serialize access due to concurrent delete` errors that we see (though there are a few functions that often cause serialization errors that we don't fix here);
2. improve the DB performance, as it no longer needs to deal with the overhead of `REPEATABLE READ` isolation levels; and
3. improve wall clock speed of these functions, as we no longer need to send `BEGIN` and `COMMIT` to the DB.

Some notes about the differences between autocommit mode and our default `REPEATABLE READ` transactions:

1. Currently `autocommit` only applies when using PostgreSQL, and is ignored when using SQLite (due to silliness with [Twisted DB classes](https://twistedmatrix.com/trac/ticket/9998)).
2. Autocommit functions may get retried on error, which means they can get applied *twice* (or more) to the DB (since they are not in a transaction the previous call would not get rolled back). This means that the functions need to be idempotent (or otherwise not care about being called multiple times). Read queries, simple deletes, and updates/upserts that replace rows (rather than generating new values from existing rows) are all idempotent.
3. Autocommit functions no longer get executed in [`REPEATABLE READ`](https://www.postgresql.org/docs/current/transaction-iso.html) isolation level, and so data can change queries, which is fine for single statement queries.
2020-10-14 15:50:59 +01:00
Patrick Cloke e4f72ddc44
Move additional tasks to the background worker (#8458) 2020-10-07 11:27:56 -04:00
reivilibre 36efbcaf51
Catch-up after Federation Outage (bonus): Catch-up on Synapse Startup (#8322)
Signed-off-by: Olivier Wilkinson (reivilibre) <olivier@librepush.net>
Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

* Fix _set_destination_retry_timings

This came about because the code assumed that retry_interval
could not be NULL — which has been challenged by catch-up.
2020-09-18 14:59:13 +01:00
Patrick Cloke 8a4a4186de
Simplify super() calls to Python 3 syntax. (#8344)
This converts calls like super(Foo, self) -> super().

Generated with:

    sed -i "" -Ee 's/super\([^\(]+\)/super()/g' **/*.py
2020-09-18 09:56:44 -04:00
reivilibre 576bc37d31
Catch-up after Federation Outage (split, 4): catch-up loop (#8272) 2020-09-15 09:07:19 +01:00
reivilibre 17fa4c7ca7
Catch up after Federation Outage (split, 2): Track last successful stream ordering after transmission (#8247)
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
2020-09-04 15:06:51 +01:00
reivilibre 58f61f10f7
Catch-up after Federation Outage (split, 1) (#8230)
Signed-off-by: Olivier Wilkinson (reivilibre) <olivier@librepush.net>
2020-09-04 12:22:23 +01:00
Patrick Cloke 5c03134d0f
Convert additional database code to async/await. (#8195) 2020-08-28 07:54:27 -04:00
Patrick Cloke 9b7ac03af3
Convert calls of async database methods to async (#8166) 2020-08-27 13:38:41 -04:00
Patrick Cloke a3a59bab7b
Convert appservice, group server, profile and more databases to async (#8066) 2020-08-12 09:28:48 -04:00
Erik Johnston a7bdf98d01
Rename database classes to make some sense (#8033) 2020-08-05 21:38:57 +01:00