### Sublogger levels not adjusted on reload ((#sublogger-levels-unchanged-on-reload))

#### Affected versions

This issue affects all Vault Community and Vault Enterprise versions.

#### Issue

Vault does not honor a modified `log_level` configuration for certain subsystem
loggers on SIGHUP.

The issue is known to specifically affect `resolver.watcher` and
`replication.index.*` subloggers.

After modifying the `log_level` and issuing a reload (SIGHUP), some loggers are
updated to reflect the new configuration, while some subsystem logger levels
remain unchanged.

For example, after starting a server with `log_level: "trace"` and modifying it
to `log_level: "info"` the following lines appear after reload:

```
[TRACE] resolver.watcher: dr mode doesn't have failover support, returning
...
[DEBUG] replication.index.perf: saved checkpoint: num_dirty=5
[DEBUG] replication.index.local: saved checkpoint: num_dirty=0
[DEBUG] replication.index.periodic: starting WAL GC: from=2531280 to=2531280 last=2531536
```

#### Workaround

The workaround is to restart the Vault server.
