While load testing our user creation code path in production, we
identified that executing the DB statement to update the `Group#user_count` column within a
transaction is creating a bottleneck for us. This is because the
creation of a user and addition of the user to the relevant groups are
done in a transaction. When we execute the DB statement to update
`Group#user_count` for the relevant group, a row level lock is held
until the transaction completes. This row level lock acts like a global
lock when the server is creating users that will be added to the same
group in quick succession.
Instead of updating the counter cache within a transaction which the
default ActiveRecord `counter_cache` option does, we simply update the
counter cache outside of the committing transaction.
Co-authored-by: Rafael dos Santos Silva <xfalcox@gmail.com>
Co-authored-by: Rafael dos Santos Silva <xfalcox@gmail.com>
If a user was granted a trust level, joined a group that granted a trust
level and left the group, the trust level was reset. This commit tries
to restore the last known trust level before joining the group by
looking into staff logs.
This commit also migrates old :change_trust_level user history records
to use previous_value and new_value fields.
Before, whispers were only available for staff members.
Config has been changed to allow to configure privileged groups with access to whispers. Post migration was added to move from the old setting into the new one.
I considered having a boolean column `whisperer` on user model similar to `admin/moderator` for performance reason. Finally, I decided to keep looking for groups as queries are only done for current user and didn't notice any N+1 queries.
* DEV: use active record `save!` instead of mini sql.
The "save" method will trigger the before_save callback "match_primary_group_changes" for User model. Else `flair_group_id` won't be removed from the user.
* check whether the method `match_primary_group_changes` called or not.
If a user always read all group messages, we will never update the
`first_pm_unread_at` column since the previous query will not return the
group_user. Instead, we should update `first_pm_unread_at` to the
current timestamp if the user has read everything.
Follow-up to 9b75d95fc6
For sites that are configured to mute some or all categories and tags
for users by default, groups can now be configured to set members'
notification level to normal from the group manage UI.
* FEATURE: set notification levels when added to a group
This feature allows admins and group owners to define default
category and tag tracking levels that will be applied to user
preferences automatically at the time when users are added to the
group. Users are free to change those preferences afterwards.
When removed from a group, the user's notification preferences aren't
changed.
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Introduce new patterns for direct sql that are safe and fast.
MiniSql is not prone to memory bloat that can happen with direct PG usage.
It also has an extremely fast materializer and very a convenient API
- DB.exec(sql, *params) => runs sql returns row count
- DB.query(sql, *params) => runs sql returns usable objects (not a hash)
- DB.query_hash(sql, *params) => runs sql returns an array of hashes
- DB.query_single(sql, *params) => runs sql and returns a flat one dimensional array
- DB.build(sql) => returns a sql builder
See more at: https://github.com/discourse/mini_sql
By default in Discourse, if a group grants a user a particular trust
level that is locked even if they are removed from the group.
With this new setting, when a user is removed from a group their
trust level is set to either the next highest trust level based on group
membership, or they are unlocked and promoted based on the default
mechanisms.
Group owners are regular users that can add or remove users to a group
The Admin UX allows admins to appoint group owners
The public group UX will display group owners first and unlock UI to
add and remove members
Group owners can only be appointed on non automatic groups
Group owners may not appoint another group owner