zitadel/cmd/setup/40/postgres/02_func.sql
Silvan dab5d9e756
refactor(eventstore): move push logic to sql (#8816)
# Which Problems Are Solved

If many events are written to the same aggregate id it can happen that
zitadel [starts to retry the push
transaction](48ffc902cc/internal/eventstore/eventstore.go (L101))
because [the locking
behaviour](48ffc902cc/internal/eventstore/v3/sequence.go (L25))
during push does compute the wrong sequence because newly committed
events are not visible to the transaction. These events impact the
current sequence.

In cases with high command traffic on a single aggregate id this can
have severe impact on general performance of zitadel. Because many
connections of the `eventstore pusher` database pool are blocked by each
other.

# How the Problems Are Solved

To improve the performance this locking mechanism was removed and the
business logic of push is moved to sql functions which reduce network
traffic and can be analyzed by the database before the actual push. For
clients of the eventstore framework nothing changed.

# Additional Changes

- after a connection is established prefetches the newly added database
types
- `eventstore.BaseEvent` now returns the correct revision of the event

# Additional Context

- part of https://github.com/zitadel/zitadel/issues/8931

---------

Co-authored-by: Tim Möhlmann <tim+github@zitadel.com>
Co-authored-by: Livio Spring <livio.a@gmail.com>
Co-authored-by: Max Peintner <max@caos.ch>
Co-authored-by: Elio Bischof <elio@zitadel.com>
Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>
Co-authored-by: Miguel Cabrerizo <30386061+doncicuto@users.noreply.github.com>
Co-authored-by: Joakim Lodén <Loddan@users.noreply.github.com>
Co-authored-by: Yxnt <Yxnt@users.noreply.github.com>
Co-authored-by: Stefan Benz <stefan@caos.ch>
Co-authored-by: Harsha Reddy <harsha.reddy@klaviyo.com>
Co-authored-by: Zach H <zhirschtritt@gmail.com>
2024-12-04 13:51:40 +00:00

83 lines
2.4 KiB
PL/PgSQL

CREATE OR REPLACE FUNCTION eventstore.commands_to_events(commands eventstore.command[]) RETURNS SETOF eventstore.events2 VOLATILE AS $$
SELECT
c.instance_id
, c.aggregate_type
, c.aggregate_id
, c.command_type AS event_type
, cs.sequence + ROW_NUMBER() OVER (PARTITION BY c.instance_id, c.aggregate_type, c.aggregate_id ORDER BY c.in_tx_order) AS sequence
, c.revision
, NOW() AS created_at
, c.payload
, c.creator
, cs.owner
, EXTRACT(EPOCH FROM NOW()) AS position
, c.in_tx_order
FROM (
SELECT
c.instance_id
, c.aggregate_type
, c.aggregate_id
, c.command_type
, c.revision
, c.payload
, c.creator
, c.owner
, ROW_NUMBER() OVER () AS in_tx_order
FROM
UNNEST(commands) AS c
) AS c
JOIN (
SELECT
cmds.instance_id
, cmds.aggregate_type
, cmds.aggregate_id
, CASE WHEN (e.owner IS NOT NULL OR e.owner <> '') THEN e.owner ELSE command_owners.owner END AS owner
, COALESCE(MAX(e.sequence), 0) AS sequence
FROM (
SELECT DISTINCT
instance_id
, aggregate_type
, aggregate_id
, owner
FROM UNNEST(commands)
) AS cmds
LEFT JOIN eventstore.events2 AS e
ON cmds.instance_id = e.instance_id
AND cmds.aggregate_type = e.aggregate_type
AND cmds.aggregate_id = e.aggregate_id
JOIN (
SELECT
DISTINCT ON (
instance_id
, aggregate_type
, aggregate_id
)
instance_id
, aggregate_type
, aggregate_id
, owner
FROM
UNNEST(commands)
) AS command_owners ON
cmds.instance_id = command_owners.instance_id
AND cmds.aggregate_type = command_owners.aggregate_type
AND cmds.aggregate_id = command_owners.aggregate_id
GROUP BY
cmds.instance_id
, cmds.aggregate_type
, cmds.aggregate_id
, 4 -- owner
) AS cs
ON c.instance_id = cs.instance_id
AND c.aggregate_type = cs.aggregate_type
AND c.aggregate_id = cs.aggregate_id
ORDER BY
in_tx_order;
$$ LANGUAGE SQL;
CREATE OR REPLACE FUNCTION eventstore.push(commands eventstore.command[]) RETURNS SETOF eventstore.events2 VOLATILE AS $$
INSERT INTO eventstore.events2
SELECT * FROM eventstore.commands_to_events(commands)
RETURNING *
$$ LANGUAGE SQL;