When I queried `system.metrics` table, I found some negative values which hint to some potential internal overflows.

```
SELECT *
FROM system.metrics
FORMAT Vertical

...

Row 31:
───────
metric:      MemoryTrackingInBackgroundProcessingPool
value:       -580863171
description: Total amount of memory (bytes) allocated in background processing pool (that is dedicated for backround merges, mutations and fetches). Note that this value may include a drift when the memory was allocated in a context of background processing pool and freed in other context or vice-versa. This happens naturally due to caches for tables indexes and doesn't indicate memory leaks.

Row 32:
───────
metric:      MemoryTrackingInBackgroundMoveProcessingPool
value:       0
description: Total amount of memory (bytes) allocated in background processing pool (that is dedicated for backround moves). Note that this value may include a drift when the memory was allocated in a context of background processing pool and freed in other context or vice-versa. This happens naturally due to caches for tables indexes and doesn't indicate memory leaks.

Row 33:
───────
metric:      MemoryTrackingInBackgroundSchedulePool
value:       -4461308831
description: Total amount of memory (bytes) allocated in background schedule pool (that is dedicated for bookkeeping tasks of Replicated tables).

...

56 rows in set. Elapsed: 0.003 sec.
```

Server version: 20.8.2.3.
{
    auto lock = getLock();
    shared->flags_path = path;
}
void Context::setUserFilesPath(const String & path)
{
    auto lock = getLock();
    shared->user_files_path = path;
}
void Context::setDictionariesLibPath(const String & path)
{
    auto lock = getLock();
    shared->dictionaries_lib_path = path;
}
void Context::setConfig(const ConfigurationPtr & config)
{
    auto lock = getLock();
    shared->config = config;
    shared->access_control_manager.setExternalAuthenticatorsConfig(*shared->config);
}
const Poco::Util::AbstractConfiguration & Context::getConfigRef() const