When a user disconnects from the hub, we would spawn off a goroutine
which would make a cluster request, and then update the user status
as offline in the DB.
This was another case of unbounded concurrency where the number of
goroutines spawned was user controlled. Therefore, we would see
a clear spike in DB connections on master when a lot of users
would suddenly disconnect.
To fix this, we implement concurrency control in two areas:
1. In making the cluster request. We implement a counting semaphore
per-hub to avoid making unbounded cluster requests.
2. We use a buffered channel with a periodic flusher to process
status updates.
We also add a new store method to upsert multiple statuses
in a single query. The statusUpdateThreshold is set to 32, which means
no more than 32 rows will be upserted at one time, keeping the
SQL query load reasonable.
https://mattermost.atlassian.net/browse/MM-64298
```release-note
We improve DB connection spikes on user disconnect
by processing status updates in batches.
```
* MM-61947 Run DND expiry job more often and round expiry time to match interval
* Move comment to make it godoc-compatible
* Change truncateDNDEndTime to work with seconds
---------
Co-authored-by: Mattermost Build <build@mattermost.com>
It was a good decision in hindsight to keep the public module as 0.x
because this would have been a breaking change again.
https://mattermost.atlassian.net/browse/MM-53032
```release-note
Changed the Go module path from github.com/mattermost/mattermost-server/server/v8 to github.com/mattermost/mattermost/server/v8.
For the public facing module, it's path is also changed from github.com/mattermost/mattermost-server/server/public to github.com/mattermost/mattermost/server/public
```
https://mattermost.atlassian.net/browse/MM-52079
```release-note
We upgrade the module version to 8.0. The new module path is github.com/mattermost-server/server/v8.
```
Co-authored-by: Doug Lauder <wiggin77@warpmail.net>
