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();
    return shared->user_files_path;
}
String Context::getDictionariesLibPath() const
{
    auto lock = getLock();
    return shared->dictionaries_lib_path;
}
VolumePtr Context::getTemporaryVolume() const
{
    auto lock = getLock();
    return shared->tmp_volume;
}
void Context::setPath(const String & path)
{
    auto lock = getLock();
    shared->path = path;
    if (shared->tmp_path.empty() && !shared->tmp_volume)
        shared->tmp_path = shared->path + "tmp/";
    if (shared->flags_path.empty())
        shared->flags_path = shared->path + "flags/";
    if (shared->user_files_path.empty())
        shared->user_files_path = shared->path + "user_files/";
    if (shared->dictionaries_lib_path.empty())
        shared->dictionaries_lib_path = shared->path + "dictionaries_lib/";
}
VolumePtr Context::setTemporaryStorage(const String & path, const String & policy_name)