We monitor the health of DB replicas, and on a fatal error,
take them out of the pool.
On a separate goroutine, we keep pinging the unhealthy replicas,
and on getting a good response back, we add them back to the pool.
https://mattermost.atlassian.net/browse/MM-50427
```release-note
Mattermost is now resilient against DB replica outages and will
dynamically choose a replica if it's alive.
Also added a config parameter ReplicaMonitorIntervalSeconds
whose default value is 5. This controls how frequently unhealthy
replicas will be monitored for liveness check.
```
Co-authored-by: Mattermost Build <build@mattermost.com>
Mockery started to throw errors like "Unexpected package creation during export data loading".
This was consistently reproducible locally and on upgrade, it has gone away.
```release-note
NONE
```
* MM-49564: Upsert in the Store vs App layer
Refactor drafts so that Upserting a draft would happen in the DB and not
in the app layer.
* Fixes mocks
* Fixes tests
* Fixes translations
* Fixes tests
* Update tests
* Fixes tests
* Addresses review comments
- renames Save => Upsert
- removes Sleep from tests
* Fixes flaky test
---------
Co-authored-by: Mattermost Build <build@mattermost.com>
* MM-45956: Optimize FileInfo stats query
We Denormalize Post.ChannelId on FileInfo.ChannelId
```release-note
The file info stats query is now optimized by denormalizing the channelID column into the table itself. This will speed up the query to get the file count for a channel on clicking the RHS.
Migration times:
On a MySQL 8.0.31 DB with
1405 rows in FileInfo and 11M posts, it took around 0.3s
On a Postgres 12.14 DB with
1731 rows in FileInfo and 11M posts, it took around 0.27s
```
https://mattermost.atlassian.net/browse/MM-45956
